ANALYSIS OF THE LIFE CYCLE IMPACTS AND
POTENTIAL FOR AVOIDED IMPACTS
ASSOCIATED WITH
SINGLE-FAMILY HOMES
SEPA
United States
Environmental Protection
Agency
-------
Disclaimer
Reference herein to any specific company or commercial products, process, or service by trade name, trademark, manufacturer, or otherwise,
does not constitute or imply its endorsement, recommendation or favoring by the United States Government.
-------
TABLE OF CONTENTS
Table of Contents iii
Background vi
Executive summary xii
1. Introduction 1
1.1 Definition of Average 1-Unit Residential Structure 2
1.1.1 New Home Construction 2
1.1.2 Occupancy and Demolition/Deconstruction 4
1.2 Estimating Life Cycle Environmental Impacts 7
1.2.1 Life Cycle Assessment - An Overview 7
1.2.2 LCA Alternatives 9
2. Life Cycle Analysis Methodology 11
2.1. Overview 11
2.2. I-O LCA and Contribution Analysis 12
2.2.1 Scope and System Boundary 12
2.2.2 Impact Categories 13
2.2.3 LCA Methodology: Contribution Analysis 14
2.2.4 Defining "Direct" and "Indirect" Impacts 16
2.3 Vector Analysis 17
2.3.1 Pre-Occupancy 17
2.3.2 Occupancy 18
2.3.3 Post-Occupancy 19
2.4 Supplemental Contribution Analysis of Selected Direct Inputs 19
2.5 Data Sources 20
2.5.1 Comprehensive Environmental Data Archive (CEDA) 20
2.5.2 Supplemental Material Use and Waste Data 20
2.5.3 Occupancy-phase Energy Use, Water Consumption, and GHG Emissions Data 20
2.5.4 Occupancy Phase Material Replacement Data 21
2.5.5 Post-Occupancy Phase Data 23
3. Results: Life Cycle Impact Analysis of Direct Inputs to Single-family Homes 25
3.1 Overvi ew 25
3.1.1 About Carpets and Rugs and Cotton 25
3.2 Overall Life Cycle Impact 26
iii
-------
3.2.1 Total Life Cycle Impacts and Impacts by Phase 26
3.2.2 Locus of Impact: Pre-Occupancy and Occupancy Phases 28
3.2.3 Comparison with Previous Studies 29
3.3 Input Contribution Analysis 30
3.3.1 Pre-Occupancy Phase 30
3.3.2 Occupancy Phase 36
3.4 Supplemental Contribution Analysis for Selected Inputs 38
3.4.1 Fiberglass and Mineral Wool (Insulation) 39
3.4.2 Ready-mixed Concrete 40
3.4.3 Wood Shingle Siding 41
3.4.4 Reconstituted Wood Products 42
3.4.5 Brick and Structural Clay Tile 43
4. Results: Output Contribution Analysis 47
4.1 Overview 47
4.2 Pre-Occupancy Phase 47
4.3 Occupancy Phase 51
4.4 Summary of Results - Output Contribution Analysis 53
5. Avoided Impacts Analysis 55
5.1 Overvi ew 55
5.2 Methodology for Analysis of Potential for Avoided Impacts 55
5.2.1 End-Use Energy Efficiency 55
5.2.2 Material Reuse and Recycling 57
5.3 Results 60
5.4 Extended Sustainability Benefits - Environmental Justice and Equity 64
6. Summary of Findings and Conclusions 71
6.1 Summary of Findings 71
6.1.1 Overall life cycle impacts of single-family homes 71
6.1.2 Direct Inputs - Pre-Occupancy and Occupancy Phases 72
6.1.3 Supplemental Analysis of Selected Inputs 72
6.1.4 Upstream Supply Chain Processes 73
6.1.6 Environmental Justice 74
6.2 Conclusions 75
6.2.1 The Use of Life Cycle, Multi-Impact Analysis in Support of SMM 75
iv
-------
6.2.2 Opportunities for Integrated Environmental Decision-Making in Support of SMM 77
6.2.3 Analytical Tools in Support of SMM 78
6.2.4 Additional Studies Others Could Undertake 79
APPENDICES
A - Single-Family Home Construction and Renovation Data
B - Input-Output Life Cycle Impact Analysis Definitions
C - Vector Analysis Methodology
D - Overall results summary
E - Input Contribution Analysis Results
F - Rationale for Selecting Direct Inputs for Supply Chain Analysis
G - Output Contribution Analysis Results
H - Report on Life Cycle Impacts of New Commercial Building Construction
I - Environmental Justice and Equity
v
-------
BACKGROUND
The construction sector is a key industrial economic sector engaged to construct, modify, renovate, and
demolish buildings and infrastructure. It is composed of establishments that build and prepare sites for
residential, industrial and commercial buildings as well as sewers, roads, bridges, and other infrastructure
projects. The construction sector responds to the nation's population and economic growth pressures,
produces needed buildings and infrastructure, provides diverse jobs and incomes, and helps maintain the
economic vitality of the small business sector.
Benefits of Construction
In 2008, construction yielded over 9 million jobs, making it one of the United States' largest industrial
and economic sectors.: Construction provides an array of jobs to individuals of diverse educational and
technical backgrounds, including truck drivers, accountants, engineers, economists, contractors,
managers, and business owners.2 Construction is a robust industry partly due to the existence of a variety
of market niches that enable small businesses to thrive. For example, in 2007, 62% of establishments
within the construction sector employed fewer than five employees.3
The vitality of the construction sector is also a key indicator of the health of the U.S. economy. The
Economics and Statistics Administration (ESA) recognizes twelve Principal Federal Economic Indicators,
two of which examine construction activity: Construction Spending and New Residential Construction.
The U.S. Census Bureau and Bureau of Economic Analysis tracks overall construction, but also, the
construction of private residential structures, such as single-family homes and apartment buildings.4 This
information can be used to identify national economic trends or to estimate the vitality of single-family
home construction.
Single-family home construction in the U.S. is a significant economic activity. In 2007, single-family
home construction accounted for 33% of the overall work value in the construction sector.5 Single-
family home construction provides economic benefits similar to those of the building construction sector
at large, such as job creation and the generation of tax revenues from worker incomes, business owner
profits, material sales, building permit approvals and extensions of utility services.6
1 Career Guide to Industries, 2010-11 Edition, Bureau of Labor Statistics, United States Department of Labor,
http://www.bls.gov/oco/cg/cgs003.htnrfemply. Accessed May 04, 2011
2 Ibid.
3 Sector 23: EC0723SG02: Construction: Summary Series: General Summary: Selected Statistics for Establishments
by Employment Size Class: 2007, 2007 Economic Census, U.S. Census Bureau,
http://factfinder.census.gov/servlet/IBQTable ?_bm=y&-_clearIBQ=Y&-ds_name=EC0723SG02&-
ib_type=NAICS2007&-_lang=en. Accessed May 04, 2011
4 About Economic Indicators, Economics and Statistics Administration, United States Department of Commerce,
http://www.esa.doc.gov/about-economic-indicators. Accessed May 04, 2011
5 Sector 23: EC0723SG05: Construction: Summary Series: General Summary: Value of Construction Work for
Establishments by Geographic Area and Type of Construction: 2007, 2007 Economic Census, U.S. Census Bureau,
http://factfinder.census.gov/servlet/IBQTable? bm=y&- clearDBQY&-ib tvpe=NAICS2007&-
ds_name=EC0723SG05&-NAICS2007=236115&-_lang=en), Accessed May 04, 2011
6 Economic Benefits of New Home Construction, Housing's Economic Impact, National Association of Home
Builders, http://www.nahb.org/fileUpload details.aspx?contentID= 155811. Accessed May 04, 2011
vi
-------
The Green Building Movement
While construction meets economic growth demands and provides an array of economic and societal
benefits, it is also a resource-intensive activity. The environmental impacts associated with buildings do
not end with their construction, but continue throughout their use, renovation, and end of life. At end of
life, building demolition materials embody all the upstream impacts associated with delivering and
operating buildings, including soil erosion, top soil loss, habitat disruption, natural resource depletion,
water and air pollution, climate disruption and land expenditure. Since the early 1990s, stakeholders have
been investing efforts to conceptualize and guide ways in which to lessen building impacts. Early
milestones in the U.S. include:
• Committee on the Environment, formed by the American Institute of Architects (AIA) (1989)
• Environmental Resource Guide, published by the AIA, funded by the EPA (1992)
• ENERGY STAR program, launched by the EPA & the U.S. Department of Energy (1992)
• First local green building program, introduced in Austin, TX (1992)
• U.S. Green Building Council (USGBC), founded (1993)
• "Greening of the White House", launched by the Clinton administration (1993)
• Leadership in Energy and Environmental Design (LEED) version 1.0 pilot program, launched by
the USGBC (1998)7
Green building introduced the concept of sustainability into the design, construction, operation,
maintenance, renovation, and demolition processes. The result has been high-efficiency structures derived
through more sustainable processes. Green buildings consume less energy, water and other resources,
protect occupant health, pollute less, and generate less waste. For example, green buildings may
incorporate sustainable materials in their construction (e.g., reused, recycled-content, or made from
renewable resources); create healthy indoor environments with minimal pollutants (e.g., reduced product
emissions); and/or feature landscaping that uses less water (e.g., native plants that survive without extra
watering).8
In 2006, the Associated General Contractors of America (AGC; http://www.agc.org) created an
Environmental Agenda, which lists seven goals. Four of these goals relate directly to materials
management:
1. Encourage environmental stewardship through education, awareness and outreach.
2. Recognize environmentally responsible construction practices.
3. Identify opportunities to reduce the impact that construction practices have on the environment,
including:
• Facilitating members' efforts to recycle or reduce construction and demolition debris.
• Identifying and maximizing the contractor's role in "green" construction
7 Green building, U.S. Environmental Protection Agency, http://www.epa.gov/greenbuilding/pubs/about.htm.
Accessed May 06, 2011
8 Ibid.
vii
-------
4. Identify ways to measure and report environmental trends and performance indicators of such
trends.
In 2010, AGC released its Building a Green Future report, which "outlines measures designed to
stimulate demand for green construction projects, boost infrastructure capacity, improve building
efficiency and green construction practices." Other efforts undertaken by the construction industry to
reduce the impacts of the sector include the following:
• The National Association of Home Builders (NAHB; http://www.nahb.org) issued Green Home
Building Guidelines that contractors can follow to make their homes more "green," including
reducing, reusing, and recycling construction waste. They also host an annual Green Building
Conference that brings together contractors and researchers to discuss new "green" construction
techniques. The NAHB Research Center also pursued research in the area of C&D materials
recycling, such as using the material on-site.
• The Building Materials Reuse Association (BMRA; http://www.buildingreuse.org) facilitates
building deconstruction and the reuse and recycling of recovered building materials. They
produce information on deconstruction techniques and information on how to make a successful
deconstruction or reuse business. They convene annually to transfer this knowledge among
contractors, government representatives, and researchers.
• The Construction Materials Recycling Association (CMRA; http://www.cdrecycling.org) aids
their members in the appropriate methods for processing material to ensure environmental
protectiveness, as well as producing a high-value product. They have developed websites to reach
out to any recyclers, users of recycled materials, and regulators in order to provide a better
understanding of C&D materials recycling. They have developed websites that contain research
and practical information for the recycling of concrete (http://concreterecycling.org), drywall
(http://drywallrecycling.org), and asphalt shingles (http://shinglerecvcling.org).
• The National Demolition Association (NDA; http://www.demolitionassociation.com) actively
promotes recycling and reuse of the materials generated during a demolition. They released a
report titled, "Demolition Industry Promotes C&D Recycling," in which they describe ways that
the industry and government can work together to overcome recycling barriers. The "members of
the National Demolition Association are committed to increasing the recycling and reuse of the
material generated" on their jobsites. They state that "recycling is good for the environment, good
for the nation's economy, a positive use of valuable commodity, and good for the country."
Today, various LEED initiatives including legislation, executive orders, resolutions, ordinances, policies
and incentives can be found in 45 states, including 442 localities, 35 state governments, 14 federal
agencies or departments, and numerous public school jurisdictions and institutions of higher education
across the United States.9 In addition, green building was projected to contribute $554 billion to the U.S.
9 USGBC: Policy and Government Resources: http://www.us gbc.org/DisplavPage.aspx?CMSPageID=1779.
Accessed October 03, 2011
viii
-------
gross domestic product between 2009 and 2013, and the green building industry was expected to generate
7.9 million jobs through 2013.10
Environmental Justice
While the impacts that buildings cast on human health and natural environment have been largely
recognized, their meaning for low-income strata has not consistently stayed in the forefront. Pursuing
green building goals with awareness and regard for the implications on low-income households can
advance environmental justice in the future.
The concept of environmental justice calls for the protection of vulnerable populations by preventing
environmental threats. Unfair land use patterns place some people in proximity to pollution from
industrial and non-industrial facilities. The lack of affordable housing opportunities for low-income
households in new-construction markets tends to keep them in these polluted environments and/or older,
existing structures. A negative effect of residing in older structures is the increased exposure to toxic
building materials, mold and allergens. Prior to 1978, lead was commonly used for products such as home
paint or plumbing and furniture. Chipping lead-based paint is the most common source of lead poisoning
in children because of how easily it is ingested. If in good condition, lead paint may not be an issue, but
under substandard conditions where paint is peeling or chipping around windows and doors, railings and
fences, the presence of lead is a genuine risk.11
Considering that the means of exposure of low-income strata include proximity to pollution from
industrial and non-industrial facilities and exposure to potentially toxic materials, mold, and allergens
inside older homes, green building goals become even more important. Reducing the demand for new
materials, minimizing the production of new materials through salvage and recycling, producing materials
that are derived through cleaner production processes, and phasing out the use of toxic materials target
some of the environmental injustices described above. Additional environmental justice goals met by the
practice of green building may include safe distancing of residential land uses from polluting facilities
and landfills, educating vulnerable communities about potential hazards and ways to protect themselves,
educating home dwellers on proper home operation and maintenance, and better positioning minority and
low-income households in new construction markets.
EPA & Sustainable Materials Management: The Road Ahead
In 1976, Congress enacted the Resource Conservation and Recovery Act (RCRA) to initiate efforts to
manage municipal and industrial solid waste generated nationwide. RCRA's goals are:
• To protect human health and the environment from the potential hazards of waste disposal
• To conserve energy and natural resources
• To reduce the amount of waste generated; and
• To ensure that wastes are managed in an environmentally sound manner.
10USGBC: Information: https://www.usgbc.org/ShowFile.aspx?DocumentID= 1991. Accessed October 03, 2011
1! http://www.epa.gov/lead/pubs/leadinfo .htm#
ix
-------
Over its initial two decades, RCRA programs have accomplished considerable achievements. For
example, post-consumer municipal and industrial solid waste recycling rates have risen, uncontrolled
dumping of hazardous waste had been curtailed, and a large portion of contaminated sites have been
cleaned up.12 However, critics of RCRA have indicated that the program has not sufficiently focused on
actions to prevent upstream pollution.13
In 2003, in Beyond RCRA: Prospects for Waste and Materials Management in the year 2020 (2020
Vision), after a joint analysis with state environmental officials, EPA introduced anew direction for
RCRA. RCRA's focus was to shift from waste management to materials management. The rationale for
the change stood in the need to become more resource efficient, and the efficient use of resources would
require wastes under RCRA to become resources (materials), where possible. Thus, within such a system,
RCRA programs would need to focus on managing materials, not wastes, to ensure the protection of
human health and the environment. Life cycle analysis would become the main feature of materials
management since it would provide insight into where in the life cycles of these resources, risks from the
chemicals could emerge or how and when materials would truly become waste.
In 2009, EPA released Sustainable Materials Management: The Road Ahead, which provides an analysis
of the major materials, products, and services in the U.S. economy and their associated environmental
impacts. The report ranks 480 materials, products and services based on 17 environmental impact
categories (EPA, 2009). EPA identified the construction of new single-family homes as one of the most
significant sources of life cycle environmental and resource use impacts in the U.S. To better understand
this finding and identify strategic opportunities for reducing or avoiding the life cycle impacts associated
with single-family homes, EPA conducted a further detailed analysis of the sources, types, and relative
magnitudes of these impacts.
About this Study14
The purpose of this study, Analysis of the Life Cycle Impacts and Potential for Avoided Impacts
Associated with Single-Family Homes, was to identify strategic opportunities for reducing or avoiding life
cycle impacts associated with single-family homes. It is documented that the dominant contributor to
most environmental impacts of single-family homes across a life cycle is energy use (Oregon DEQ,
2010). Energy efficiency has long been a topic of research and an area of focus when identifying
opportunities for reducing the impacts of single-family homes.15 However, materials also matter.
The first objective for this study was to quantify the environmental impacts embodied in materials,
products and services consumed during the life cycle of single-family homes, and rank-order these inputs
12 Beyond RCRA, Waste and Materials management in the Year 2020, United States Environmental Protection Agency,
Office of Solid Waste, 2003. http://www.epa.gov/osw/inforesources/pubs/vision.pdf. Accessed on May 9,2011
13 Ibid.
14This study focuses on single-family housing, but in July 2010, the EPA funded development of another follow-on report
to the Sustainable Materials Management Relative Ranking Analysis that analyzes the life cycle impacts associated with
"new office, industrial and commercial building construction." The full report is included in Appendix H.
15 Two examples at the federal level include the Energy Star program and associated Energy Star Qualified New Homes,
which was launched by the U.S. EPA and the Department of Energy (DOE) to recognize homes that were substantially
more energy efficient than the model energy code. DOE developed a number of other programs through the Office of
Energy Efficiency and Renewable Energy (EERE). See Homes: energy.gov,
http://www.energy.gov/energyefficiency/homes.htm. Accessed May 13,2011
-------
according to the magnitude of their embodied impacts. Several of the top-ranked materials and products
were analyzed to pinpoint the specific supply-chain processes where their most significant impacts in the
context of single-family homes were occurring. In addition to analyzing the upstream processes for a
select group of top-ranking materials and products, EPA analyzed the impacts of all of the supply-chain
processes needed to deliver and operate new single-family homes in the U.S.
The second objective for this study was to propose example changes and reveal the potential for reducing
impacts across diverse environmental impact categories if these changes were to be incorporated on a
national scale. Proposed changes encompassed optimizing the end-use energy efficiency of homes as well
as increasing recycling and reuse of select building materials.
The third objective for the study was to state environmental justice and affordable housing issues as they
pertained to the results of the analysis. Increasing the recycling and reuse of building materials may
reduce the pollution burdens that disadvantaged households face due to their proximity to polluting
facilities. This environmental strategy also helps reduce housing costs, which in turn, should increase
low-income households' access to sustainable, green housing. The environmental justice discussion also
relayed potential human health and worker safety considerations involved with providing green homes at
a lower cost.
XI
-------
EXECUTIVE SUMMARY
Over 110 million residences exist in the United States, almost 70% of which are single-family homes.
The range of materials, goods, and services used to construct, maintain, repair, and renovate these homes
is complex, involving—directly or indirectly—almost every sector of the U.S. economy. In the report
Sustainable Materials Management: The Road Ahead, EPA identified the construction of new single-
family homes as one of the most significant sources of life cycle environmental and resource use impacts
in the U.S.
To better understand this finding and identify strategic opportunities for reducing the life cycle impacts
associated with single-family homes, EPA conducted a more detailed analysis of the sources, types, and
relative magnitudes of these impacts. This detailed analysis considers all of the life cycle phases—pre-
occupancy, occupancy, and post-occupancy—and provides a national, economy-wide strategic view of
the environmental impacts associated with single-family homes.16
Methodology
An I-O LCA tool was used to analyze life cycle environmental impacts associated with each life cycle
phase of single-family homes and to quantify the potential for avoiding those impacts. Life cycle impacts
were characterized using the following 17 environmental impact categories from the 2020 Vision Relative
Ranking Analysis (EPA, 2009):
1. Abiotic depletion potential (ADP)
2. Land use competition (LUC)
3. Global warming potential (GWP)
4. Stratospheric ozone depletion potential (ODP)
5. Human toxicity potential (HTP)
6. Freshwater aquatic ecotoxicity potential (FAETP)
7. Marine aquatic ecotoxicity potential (MAETP)
8. Terrestrial ecotoxicity potential (TETP)
9. Freshwater sediment ecotoxicity potential (FSETP)
10. Marine sediment ecotoxicity potential (MSETP)
11. Photochemical ozone creation potential (POCP)
12. Acidification potential (AP)
13. Eutrophication potential (EP)
14. Energy consumption (EC)
15. Water consumption (WC)
16. Material input (MTL)
17. Waste (WST)
The analysis consisted of the following general steps:
16 This analysis also provides a method for scaling-up the results of site- or unit-focused analyses to evaluate their
potential to have a nationally significant impact. The analysis did not attempt to assess the effects of unit- or site-
level changes in residential building methods. Rather, it was used to develop insights into where such additional
analyses could best be focused.
xii
-------
1. Identification and analysis of top-ranted supply chain processes, materials, products, and
services:
• Input contribution analysis was used to evaluate and identify the materials, products, and services
directly consumed during the construction and use of single-family homes ("direct inputs") that
contribute most significantly to overall life cycle environmental impacts.
• Supplemental contribution analyses were conducted for selected direct inputs to characterize the
supply chain processes contributing most significantly to the life cycle impacts associated with
these selected direct inputs.
• An output contribution analysis was conducted to holistically identify the upstream supply chain
processes in the economy where the most significant sources of life cycle environmental impacts
associated with new single-family homes occur.
• In conjunction with input and output analyses, vector analyses were used to rank order either the
direct inputs based on their relative contributions to the overall life cycle impacts of single-family
homes, or the upstream supply chain processes associated with the delivery and operation of new
single-family homes in the U.S.
2. Estimation of the potential for avoided impacts:
• Results of the I-O LCA, supplemental contribution analyses, and vector analyses were reviewed
and hypothetical scenarios for avoided impacts were identified based on their potential to reduce
material and resource intensity and/or illustrate the range of policy actions available to address
the environmental footprint of single-family homes. The analyzed scenarios can be grouped into
two broad groups: energy-efficiency improvement scenario and increased recovery and utilization
of recovered materials scenario.
Summary of Findings
Overall Lifecycle Impacts
The analysis of the overall life cycle impacts associated with single-family homes indicates the following:
• The majority of life cycle impacts associated with single-family homes occurs during the
occupancy phase. The one exception to this finding is that the majority of life cycle material
input occurs during the pre-occupancy phase.
• Life cycle impacts associated with the post-occupancy phase are relatively insignificant for all but
the waste impact category. However, this finding should not be interpreted to imply that choices
regarding the management of building demolition/deconstruction material have an insignificant
effect. In fact, when viewed across the life cycle or product boundaries, the recycling and reuse of
construction and demolition materials can significantly offset impacts associated with the input of
virgin material into construction and renovation of single-family homes, other buildings and
infrastructure. Section 5.3 of the report explores several pathways by which increased recycling
and reuse of products and materials recovered from single-family homes offset impacts of various
other products and industries.
• For the pre-occupancy and occupancy phases, most of life cycle impacts associated with single-
family homes are indirect—they result from upstream supply chain processes and are embodied
xiii
-------
in the direct inputs to the single-family home. Thus, a policy perspective focused solely on direct
inputs (e.g. brick, concrete, wood) without an understanding of the upstream supply chain
processes (e.g. manufacturing, distribution) and the associated connections may miss
opportunities to effectively reduce the environmental impacts of single-family homes.
Input Contribution Analysis of Life Cycle Impacts of Direct Inputs17
The input contribution analysis was conducted to estimate the life-cycle impacts of direct inputs to the
pre-occupancy and occupancy phases of single-family homes. The direct inputs were ranked based on
their relative contributions to the overall life cycle impacts associated with single-family homes.
• Pre-Occupancy Phase
A diverse mix of direct inputs contributes to the overall life cycle impacts of single-family homes,
including building materials (e.g., brick and structural clay tile, ready-mixed concrete,
reconstituted wood products), more highly engineered products (e.g., miscellaneous plastic
products), and services (e.g., trucking and courier services).
Depending on the impact category, impacts associated with the top 10 inputs account for
anywhere from just below 2% to just above 16% of the total life cycle impact associated with
single-family homes . For some impact categories, the overall life cycle impacts associated with
inputs into this phase are the accumulation of impacts across a diverse range of inputs. For other
impact categories, the overall life cycle impacts are embodied in a more limited set of inputs.
• Occupancy Phase.
The input contribution analysis for the occupancy phase of single-family homes was focused on
energy and water inputs and materials and products replaced during the life span of homes. The
analysis highlighted electric services and natural gas distribution as well as insulation and siding
as some of the top most highly ranked direct inputs.
Depending on the impact category, top 6 most highly ranked direct inputs contribute anywhere
from 20% to 90% of the total life cycle impact associated with single-family homes, with electric
services (utilities) typically contributing the highest percentage. Thus, opportunities exist to
significantly reduce overall life cycle impacts of single-family homes by focusing on a narrow set
of inputs used in the occupancy phase, and the most significant reductions could be realized
through reductions in electricity consumption and/or impacts associated with upstream supply
processes needed for electricity generation and distribution.
Supplemental Analyses of Selected Materials and Products
Select materials, products, and services representing direct inputs to single-family homes were identified
for further supplemental analyses based on the results of the input contribution and vector analyses and
whether they represented a clearly-defined material or product—i.e., a material or product for which an
SMM-oriented policy response could be feasible.
17 Contribution analyses were conducted for the pre-occupancy and occupancy phases. They were not conducted for
the post-occupancy phase due to the limited scope and contribution of impacts associated with this phase relative to
the overall life cycle impact associated with single-family homes. See Section 2.3 for additional discussion.
xiv
-------
• Fiberglass and mineral wool insulation - The input contribution analyses highlight the significant
contribution of fiberglass and mineral wool insulation to the overall stratospheric ozone depletion
potential (ODP) life cycle impacts of single-family homes. The supplemental analysis suggests
that nearly half of the ODP impacts associated with these products occur as a result of the
manufacturing phase of fiberglass and mineral wool insulation.
• Ready-mixed concrete - The input contribution analysis suggests that ready-mixed concrete
contributes significantly to a diverse set of life cycle impacts associated with single-family
homes, including global warming, photochemical ozone creation, acidification, eutrophication,
abiotic depletion, energy consumption, material input, and waste. The supplemental contribution
analysis suggests that hydraulic cement manufacturing is a key source of embodied impacts in the
upstream supply chain, as well as that the manufacture of ready-mixed concrete itself is
significant due to the associated direct emissions.
• Wood Shingle Siding- The occupancy-phase input contribution analysis suggests that wood
shingle siding contributes to the life cycle impacts associated with single-family homes primarily
based on the land use competition (LUC) factor. Forestry products and related services contribute
most significantly to the LUC impacts embodied in wood shingle siding, reflecting the
geographic footprint of forests managed for wood production. Other embodied impacts of wood
shingle siding are associated with electric services and sawmills and planing mills.
• Reconstituted wood products - The input analysis suggests a broad range of impacts associated
with reconstitutedwood products, particularly across the natural resources and land use and
pollution impacts. The supplemental analysis suggests that energy consumption and waste
impacts can be attributed to the reconstituted wood products manufacturing process. Embodied
natural resources and land use impacts can be attributed to forestry products and related services
and electric services.
• Brick & Structural Clay Tile - The input contribution analyses suggest that brick and structural
clay tile contribute significantly to the overall life cycle toxicity impacts associated with single-
family homes, particularly human toxicity, marine aquatic ecotoxicity, and freshwater sediment
ecotoxicity. The supplemental contribution analysis suggests that direct emissions from the
manufacturing of brick and structural clay tile account for close to half of these toxicity impacts.
Output Contribution Analysis of Upstream Supply Chain Processes
Whereas the input contribution analysis focuses on the relative contribution of direct inputs to the overall
life cycle impacts, the output contribution analysis disaggregates these impacts to their original sources in
the upstream supply chain of single-family homes. The output contribution analysis was conducted for the
pre-occupancy and occupancy phases of single-family homes, and it highlights energy and related supply
chain processes across both of these life cycle phases of single-family homes.
• Pre-Occupancy Phase
The pre-occupancy phase output contribution analysis highlights the supply chain processes of
materials, products and services associated with new building construction (e.g., brick and
structural clay tile, sand and gravel, mineral wool, electric services, trucking and courier
services, crude petroleum and natural gas andcoa/).
xv
-------
Depending on the impact category, impacts associated with the top 10 supply chain processes
utilized in the pre-occupancy phase account for anywhere from less than 3% to almost 60% of the
total life cycle impact associated with single-family homes. The analysis highlights the relative
differences in perspectives offered by input and output contribution analysis. The output
contribution analysis highlights that about 10% of the overall abiotic depletion potential (ADP)
impacts associated with the supply-chain processes of the pre-occupancy phase can be attributed
to crude petroleum and natural gas and coal production. From an input contribution perspective,
around 2% of the overall ADP impacts associated with the inputs into the pre-occupancy phase
can be explained by the top 10 ranked ones. This suggests that petroleum, natural gas, and coal
production are part of a number of different supply chains.
• Occupancy Phase
The occupancy phase output contribution analysis highlights supply chain processes associated
with replacement materials, e.g., agriculture, forestry, and fishery services, paper and
paperboard mills, anaplasties materials and resins as inputs to replacement wood products.
Fiberglass and mineral wool insulation is a rare example of a product for which supply chain
processes were highlighted by both pre-occupancy and occupancy phase output analysis; this
impactful product is used not only in new construction but also for home maintenance and
renovation. Broadly, however, materials associated with new building construction are less
important in the supply chain associated with home use. Both pre-occupancy and occupancy
phase analyses highlight energy services and related materials.
Depending on the impact category, impacts associated with the top 10 supply chain processes
utilized in the occupancy phase account for anywhere from about 15% to 95% of the total life
cycle impacts of single-family homes.
Potential for Avoided Impacts Scenarios
Environmental Impact
Additional analyses were conducted to analyze the potential for avoiding impacts through reduced
material and resource use. Included were the following scenarios:
Table ES-1
Avoided Impacts Scenarios Analyzed
Product Category
End-use electricity
End-use natural
gas
Ready-mixed
concrete
Carpets and Rugs
Scenario
Efficiency improvements associated with
electric water heating, space heating, space
cooling, refrigeration, and lighting
Efficiency improvements associated with
natural gas water heating and space heating
Ready-mixed concrete from demolished/
deconstructed single-family homes processed
and used as aggregate for roadway
construction.
Carpets and rugs removed from single-
family homes as a result of renovation and/or
demolition/deconstruction processed and
used as resin for manufacturing of various
synthetic materials.
Improvements
Efficiency improvements ranging from
12% to 50%, depending on end use
Efficiency improvements ranging from 6%
to 12%, depending on end use
20% increase in recycling of ready -mixed
concrete from current levels, resulting in
1% reduction in sand and gravel used as
aggregate for roadway construction
5% increase in recycling of carpets and
rugs from current levels, resulting in a
0.65% reduction in resin from other
sources used to manufacture various
synthetic materials
XVI
-------
Brick and
structural clay tile
Reconstituted
wood products
Brick from demolished/deconstructed single-
family homes reused in new construction
Reconstituted wood products from
demolished/ deconstructed single-family
homes burned as fuel for power generation in
paper and wood products industry
15% increase in reuse of old brick in new
buildings relative to current levels
Wood recovery rates increased to a level
equivalent to replacing 5% of coal
currently consumed by wood and paper
products industry
The results of the avoided impacts analysis suggest the following:
• Combined, the energy efficiency improvements and material reuse/recycling scenarios considered
in the avoided impacts analysis could result in 5-28% reductions in the life cycle impacts
associated with single-family homes.
• Improving efficiencies in lighting, space heating, space cooling and water heating could result in
reductions of 12-27% in the life cycle impacts associated with single-family homes across a range
of natural resource use, toxicity, and pollution impact categories. The most significant
contributions to avoided impacts would result from the efficiency improvements in natural gas
water and space heating, lighting, and electric space cooling.
• Improvements in material reuse and recycling rates considered in the analysis could result in
reductions of 6-14% in life cycle impacts associated with single-family homes across a range of
natural resource, toxicity, and pollution impact categories. The recycling of carpets and rugs into
resin for various synthetic materials accounted for most of the potential avoided impacts,
including 9-13% reductions in life cycle stratospheric ozone depletion potential (ODP) and three
categories of ecotoxicity impacts. The increased recycling of salvaged reconstituted wood
products as an energy source could offset 7% of life cycle abiotic depletion potential (ADP) and
5% of the life cycle waste (WST) impacts associated with single family homes. While reductions
in life cycle impacts could be achieved through increased recycling of concrete and reuse of
brick, the contribution of the scenarios considered to reducing overall life cycle impacts
associated with single-family homes would be small. However, it is important to note that even if
an offset impact for a single material could be small, the sum of such small impacts across the
many materials used in single-family homes should result in more significant environmental
savings overall.
Environmental Justice & Equity
The avoided impact scenarios quantified the environmental benefits that can accrue from using recovered
materials as replacements for virgin materials and improving energy efficiency. The analysis
demonstrated how these strategies can help single-family homes perform better environmentally over
their life cycles. However, the benefits from implementing the two strategies extend beyond those
benefits that can be measured purely by environmental impact categories; use of recovered materials in
construction and improvements to home energy efficiency reduce housing costs and environmental
pollution and thus, provide social, economic and health benefits to disadvantaged communities. Other co-
benefits that result from increasing the recycling and reuse of materials include job creation in local
deconstruction and recycling/reuse industries as well as overall community revitalization from any
associated economic activity.
xvn
-------
Recovered materials are often less expensive than traditional construction materials and their increased
incorporation can help reduce both upfront and renovation housing costs in attempts to provide and
maintain affordable, green homes. However, for recovered materials to be of service to low-income
households, they need to be chosen judiciously. One caution is that potentially harmful materials that had
historically circulated in the construction and maintenance of buildings could be reintroduced. The U.S
EPA works to promote safe reuse and has gathered useful information, e.g., on how reuse stores and their
customers can safely manage older building materials that may contain lead-based paint.18 Second
concern is that depending on the application, the structural and energy-efficiency performance of certain
recovered materials may not be adequate. For example, building codes may not allow salvaged lumber for
structural applications due to concerns over structural integrity, or a salvaged single-pane window for
exterior applications due to energy inefficiency.19 Finally, for repair and maintenance costs not to
overcome the upfront savings, recovered materials need to be sufficiently durable. Materials salvaged
from the structures of periods that boasted construction of better quality may be preferential.20
Conclusions
The national-scale life cycle analysis uses the I-O LCA approach to consider all of the life cycle phases
and provides a national, economy-wide strategic view of the nature, source, and locus of life cycle
impacts associated with a key economic activity - construction of single-family homes. The I-O LCA
approach provides a method for scaling-up the results of site- or unit-focused analyses to evaluate their
potential to have a nationally significant impact.
Broadly, the analysis demonstrates relationships among supply chain processes and suggests the
interconnectivity among producers, service providers, and consumers—individuals, businesses, and
governments—in the economy. Policy interventions require integrated environmental decision making so
as to occur at multiple points in a supply chain, involve multiple stakeholders and policy instruments.
Varying levels of coordination across environmental programs could be necessary to address life-cycle
impacts associated with specific inputs. For example, if a material, product, or service contributes
significantly to overall life cycle impacts through impact categories that encompass diverse environmental
media, a coordinated response among environmental programs, using different authorities, could yield the
best approaches. Conversely, if an input contributes significantly to overall life cycle impacts through
impact categories affecting a limited number of environmental media, a directed response through a
single program or a limited set of authorities might be more effective.
From the perspective of life cycles and products, it is important to consider opportunities to preserve
natural capital by reusing and recycling materials at the end-of-life as inputs to upstream supply chain
processes associated with production or use phases (e.g., reuse of bricks or hardwood flooring). It is also
18 U. S EPA, Pollution Prevention and Toxics, 2011, Frequent Questions, General Information about Lead, 2011:
http://toxics.supportportal.com/link/portal/23002/23019/Article/32411/Building-material-reuse-stores-sometimes-
accept-older-materials-which-have-been-coated-with-lead-based-paint-and-could-pose-a-lead-poisoning-hazard-In-
particular-older-windows-and-doors-are-likelv-to-. Accessed August 15, 2011.
19 King County Department of Natural Resources and Parks, Solid Waste Division & City of Seattle Department of
Planning and Development, 2006. {Green home remodel} salvage & reuse:
http://vour.kingcountv.gov/solidwaste/greenbuilding/documents/Green home remodel-salvage.pdf. Accessed
August 15, 2011.
20 Ibid.
xviii
-------
important to consider opportunities for avoiding impacts in another economic sector (e.g., recycling of
carpets and rugs into resin for various synthetic products or recycling of wood panels as fuel).
The affordability and environmental justice discussions suggest that policies or strategies that involve
reducing material or energy inputs into single-family homes have the potential to result in co-benefits for
low-income communities. These environmental strategies provide meaningful ancillary benefits to help
resolve social problems and as such should garner interest and support of various public entities.
xix
-------
1. INTRODUCTION
The U.S. housing stock includes over 110 million units, almost 70% of which are single-family
homes.21 The range of materials, goods, and services used to construct, maintain, repair, and
renovate these homes is complex, involving—directly or indirectly—almost every sector of the
U.S. economy. In the report Sustainable Materials Management: The Road Ahead22, EPA ranked
the construction of new residential 1-unit structures23 among the top 10 products of the U.S.
economy in terms of relative life cycle environmental and resource use impact.24 The analysis
supporting this conclusion considered the life cycle impacts associated with single-family home
construction. Additional impacts are associated with the occupancy and demolition or
deconstruction of these buildings.
To better understand these findings and identify strategic opportunities for reducing or avoiding
the life cycle impacts associated with single-family homes, EPA conducted a more detailed
analysis of the sources, types, and relative magnitudes of these impacts. This more detailed
analysis considers all of the life cycle phases—pre-occupancy, occupancy, and post-occupancy—
and provides a national, economy-wide strategic view of the environmental impacts associated
with single-family homes. It identifies the supply-chain processes, materials, products, and
services associated with the greatest life cycle impacts and begins to quantify the impacts that
could be avoided by reducing the amount of material and resources consumed over the life cycle
of a single-family home.
The following report provides additional context, describes the methodology and data sources,
and presents results of analyses of the life cycle impacts and the potential for avoided impacts
associated with single-family homes. The remainder of this section provides additional
background regarding the materials and resources used throughout the life cycle of the "typical"
single-family home and describes the general sources of the life cycle impacts. Section 2
describes the methodology and data sources used for the life cycle impact analyses, Sections 3
and 4 respectively, present the results of input and output, more detailed life cycle impact
analyses, of the national stock of single-family homes; Section 5 describes the methodology and
21 According to the American Community Survey (ACS), the U.S. housing stock as of 2009 included 112
million housing units, 63.1% of which were 1-unit detached structures and 5.8% of which were 1-unit
attached structures. Attached structures include "town homes or row homes where each housing unit is
separated by a ground-to-roof wall and where no housing units are constructed above or below." (DOC,
2009)
22 For a copy of the report, visit: http://www.epa.gov/epawaste/inforesources/pubs/vision.htm
23 The U.S. Bureau of Economic Analysis (BEA) input-output tables refer to the economic sector that is the
subject of this report as "new residential 1-unit structures" (BEA code 110101). This report uses the term
"single-family homes" interchangeably with the BEA definition.
24 The findings of the report were based on the 2020 Vision Relative Ranking Analysis, which ranked the
relative impact of the 480 materials, products, and services included in the U.S. Economic Accounts based
on 13 environmental impact categories, including, for example, climate impacts, human toxicity, and
ecological toxicity, and four other categories of impact, specifically, material use, waste, water use, and
energy use (EPA, 2009).
1
-------
results of the avoided impacts analysis, and Section 6 summarizes this information and concludes
the report.
1.1 DEFINITION OF AVERAGE I-UNIT RESIDENTIAL STRUCTURE
The 2020 Vision Relative Ranking Analysis, the study used to develop the conclusions of the
Sustainable Materials Management report, used an input-output life cycle analysis (I-O LCA)
methodology employing economic data available from the U.S. Bureau of Economic Analysis
(BEA), as described in Section 1.2. This current analysis adopts a similar approach. The most
recent year for which BEA data were available in the Comprehensive Environmental Data
Archive (CEDA) tool used to conduct the analysis, was 1998.25 Therefore, 1998 was used as the
reference year for the analysis of life cycle impacts associated with single-family homes.
1.1.1 New Home Construction
In 1998, there were an estimated 104 million residential homes in the U.S., 1.16 million of which
were newly built in that year.26 Wooden structures dominated and continue to dominate the U.S.
single-family housing stock. The average size single-family home built in 1998 was 2,190 square
feet (sf). In comparison, the average size home built in 1973 was 1,660 sf, and the average size
home built in 2009 was 2,392 sf (DOC, 2010). The average size of a single-family home has
generally increased over this period, though since a peak in 2007-2008, the average home size has
trended downward.
The types and quantities of materials used in single-family home construction vary widely,
influenced by factors such as local conditions (e.g., climate, cultural history), building codes,
architectural trends, and economic factors (e.g., cost of building materials). Table 1-1 presents a
summary of the average quantity of materials used in a single-family home built around 1998.
Table 1-1
Average Quantities of Materials Used in Construction of a Single-family Home in 2000
Item Average Quantity
Lumber 13,837 board feet
Sheathing 13,118 square feet
Concrete 19 tons
Exterior siding material 3,206 square feet
Roofing material 3,103 square feet
Insulation 3,061 square feet
Wall material 6,050 square feet
Ceiling material 2,335 square feet
Ducting 226 linear feet
Windows 19 units
25 Although the 2002 BEA data are available now, they were still under development at the time this
analysis was conducted.
26 DOE (2011), Tables 2.2.1 and 2.5.1.
-------
Table 1-1
Average Quantities of Materials Used in Construction of a Single-family Home in 2000
Item Average Quantity
Exterior doors 4 units (3 hinged, 1 sliding)
Flooring material 2,269 square feet
Interior doors 12 units
Closet doors 6 units
Garage doors 2 units
Fireplace 1 unit
Bathroom fixtures 3 toilets, 2 bathtubs, 1 shower, 3 sinks
Kitchen fixtures 1 sink
Kitchen appliances 1 range, 1 refrigerator, 1 dishwasher, 1 garbage
disposal, 1 range hood
Laundry appliances 1 washer, 1 dryer
Heating and cooling system 1 system
Source: NAHB (2004)
In addition to material inputs, single-family home construction involves labor, engineering and
inspection services, financial services (e.g., banking, insurance), services associated with
employee benefits, etc. Table 1-2 summarizes information provided by NAHB regarding the cost
breakdown of the average 2,150 sf single-family homes built around 1998.
Table 1-2
1998 Cost Breakdown of a 2,150-Square-Foot, New Single-Family Home27
Cost Component
USD ($2009) Contribution to total
Finished Lot 64,622 24%
Construction Cost
Inspection/Fees 4,223 2%
Shell/Frame
Framing 30,925 11%
Windows/Doors 10,271 4%
Exterior Finish 11,304 4%
Foundation 16,130 6%
Wall/Finish Trim 28,210 10%
Flooring 7,210 3%
Equipment
Plumbing 8,837 3%
Electrical Wiring 5,638 2%
27 Based on a NAHB Survey asking builders to provide a detailed breakdown of the cost of constructing a
2,150 SF home with 3 or 4 bedrooms on a 7,500 to 10,000 sf lot. For a comparison, average sales price of a
new home in 42 surveyed markets was $226,680 in $1998 (DOE, 201 la, Table 2.5.8), which is the price
paid by the consumer including profit, fees and commissions. The actual average price of a single-family
home built in 1998 was $158,620 in producer's price, which does not include profit, fees and commissions
(calculated based on the BEA 1998 input-output table). Differences among the NAHB survey, DOE data
and BEA data are due to differences in the scope of the sample and in the price definitions (i.e., consumer
vs. producer price) as well as differences in base years.
3
-------
Table 1-2
1998 Cost Breakdown of a 2,150-Square-Foot, New Single-Family Home27
Cost Component
Lighting Fixtures
HVAC
Appliances
Property Features
Other Costs
Financing
Overhead & General Expenses
Marketing
Sales Commission
Profit
Total
Cost
USD ($2009) Contribution
1,560
6,170
2,165
17,566
5,151
15,644
3,840
9,238
25,161
273,865
to total
1%
2%
1%
6%
2%
6%
1%
3%
9%
100%
1.1.2 Occupancy and Demolition/Deconstruction
NAHB data indicate that the average lifespan of a single-family home in the U.S. is on the order
of 50 years. In their analysis of the residential construction sector, the Oregon Department of
Environmental Quality (DEQ), assumed an average lifespan of 70 years for homes built in the
Portland, OR area. This assumption was based on a scan of American Housing Survey data,
which indicated that lifespan is a function of the period when the home was built and typically
ranges from 50 to 200 years (Oregon DEQ, 2010). In the absence of definitive statistics on the
life-spans of single-family homes, the analysis adopted O'Connor's (2004) results of a survey on
service lives for non-residential North American buildings. These buildings were demolished
between 2000 and 2003 in a major North American city of Minneapolis/St. Paul. According to
the survey, service life of non-residential wood structures was 51.6 years. This life span was
adopted as a proxy for the life span of U.S. single-family homes because of the similarity between
the non-residential wood structures and U.S. single-family homes in the use of wood as the
dominant construction material. Nevertheless, just as 70 years was admittedly an uncertain
number in the Oregon DEQ study, so is 51.6 years here. Firstly, a meaningful relationship
between home age and likelihood of demolition does not exist (Oregon DEQ, 2010). For
example, even when a home is not old, but is small, raising land values may motivate a developer
to demolish it and replace it with a new, bigger and more expensive home so as to maximize his
potential for profit. Conversely, in certain circumstances, homebuyers may find older homes
aesthetically appealing or extremely affordable for the neighborhood and through continuous
resale extend their service lives. In both examples, longevity is independent of the reasonably
anticipated durability of a structure obscuring the relationship between home age and likelihood
of demolition. It should be recognized, however, that the purpose of the lifespan figure is to
obtain an overall average, and not the range of lifespans associated with individual circumstances.
Secondly, these factors that affect service lives and extend beyond just longevity of structural
materials, e.g. functional obsolescence, community planning or neighborhood conditions, may
not equally affect non-residential and residential structures (O'Connor, 2004). This limits the
applicability of the non-residential service life to residential structures. However, since the
4
-------
analysis aims to project into the future and anticipate future longevity of homes, data on
residential structures that have already been demolished would not be fully applicable either
(Oregon DEQ, 2010).
During the occupancy phase of a single-family home, the period after the home has been built and
before it is demolished or deconstructed, resource inputs, such as electricity, natural gas, and
water, are required to operate appliances and other systems. In addition, materials are used to
replace worn out or outdated components of the home and remodel or renovate the structure.
Table 1-3 describes examples of the types of components typically replaced in a single-family
home and average lifespans of common components, which correspond to replacement periods.
Based on information provided in the study by the Oregon DEQ (2010), costs for replacements
during the life-time of a standard residential home are on the order of $180,000 ($2010) (see
Appendix Al). By comparison, the life-time energy costs for operating the average home built in
1998 would be on the order of $90,000 ($2010).28
Examples
Home Component
Table 1-3
of Average Life Expectancies of Home Components
Avg. Years to
Replacement*
Appliances and HVAC
Dishwasher 9
Range 13-15
Clothes washer/dryer 10-13
Water heaters 10-11
Boilers and furnaces 13-21
Cabinetry
Kitchen and other cabinets 3 8
Medicine cabinets 32
Doors and Windows
Exterior doors 33
Aluminum windows 15-20
Wood windows 30+
Electrical and lighting
Wiring Lifetime
Electrical fixtures 38
Electrical controls 10+
Flooring
Hardwood floors >50
Carpet 8-10
Linoleum flooring 17
Vinyl flooring 26
Tile flooring >50
Ref.
0)
0)
0)
0)
0)
(2)
Home Component
Footings and Foundations
Poured concrete
Concrete block
Waterproofing
Framing, engineered lumber
Timber frame homes
Engineered trusses
Wood Panels
Oriented Strand Board
Plywood
Insulation
Cellulose
Fiberglass
Roofing
Asphalt
Slate
Siding, trim and accessories
Brick siding
Cement shingle siding
Other siding materials
Trim
Shutters (wood exterior)
Walls, Ceilings and Finishes
Standard gypsum
Avg. Years to
Replacement*
Lifetime
Lifetime
10
Lifetime
Lifetime
25-30
>50
>50
>50
20
>50
Lifetime
31
19
25
20
Lifetime
Ref.
0)
0)
0)0)
28 FromDOE (2011a), Table 2.3.9. The average annual energy expenditure associated with a home built in
1998 is $1,671 in $2009. Assuming a 51.6-year lifespan and adjusting for inflation, this equates to a life-
time energy cost of $87,600 in $2010.
-------
* Lifetime means for the full lifespan of the home.
Sources:(1) NAHB and Bank of America (2007)
(2) Oregon DEQ (2010), Appendix 4
In addition to the materials and resources associated with construction and use, additional
materials and resources are required when a single-family home is demolished and/or
deconstructed29. These include the equipment and labor inputs required to remove the building,
stabilize the site, and landfill or recycle demolition waste.
Construction and demolition (C&D) materials are generated during all 3 phases of a single-family
home, construction, renovation, and demolition/deconstruction. EPA estimated that nationwide,
renovation generated the majority of C&D materials associated with residential buildings in 2003.
EPA further estimated that approximately 14.4 million tons of material was generated from
demolition/deconstruction of single-family homes in 2003. On a weight basis, concrete
contributed the largest fraction of this material, comprising as much as 68% of the total weight of
C&D materials for homes with a full basement and garage (EPA, 2003a). Recovered and recycled
C&D materials can be a source of material for single-family home construction and renovation.
Table 1-4 lists typical components of C&D materials.
Table 1-4
Typical Components of C&D Materials
Material Components
Wood
Drywall
Metals
Plastics
Roofing
Masonry
Glass
Miscellaneous
Cardboard
Concrete
Asphalt pavement
Content Examples
Forming and framing lumber, stumps/trees, engineered wood
Sheetrock (wallboard)
Pipes, rebar, flashing, wiring, framing
Vinyl siding, doors, windows, flooring, pipes, packaging
Asphalt, wood, slate, and tile shingles, roofing felt
Cinder blocks, brick, masonry cement
Windows, mirrors, lights
Carpeting, fixtures, insulation, ceramic tile
From newly installed items such as appliances and tile
Foundations, driveways, sidewalks, floors, road surfaces
Sidewalks and road structures made with asphalt binder
Source: EPA 2003a
29 Deconstruction, the systematic dismantling of a structure, can be used in various degrees in order to
salvage usable materials. Techniques can range from reuse of an entire structure or foundation, to select
assemblies and systems, to the careful removal of specific materials or items. See:
http://www.epa.gov/osw/conserve/rrr/imr/cdm/reuse.htm
-------
1.2 ESTIMATING LIFE CYCLE ENVIRONMENTAL IMPACTS
1.2.1 Life Cycle Assessment — An Overview
Life Cycle Assessment (LCA) is a tool used to quantify the environmental impacts of a product
system throughout its life cycle—from raw material acquisition, manufacturing, transportation,
assembly, use and disposal. LCA can be used to assess impacts in terms of a single environmental
concern, such as climate change, or across multiple environmental impacts. Figure 1-1 illustrates
the concept of a product life cycle, where the "product" in this case is the single-family home.
Figure 1-1
Material Flows, Resource Withdrawals, and Emissions
In the Life Cycle of a Home
Energy,
Water
inputs
Resource
Extraction
Material return flows
Energy,
Water
inputs
Material
Processing
Product
Manufacturing
I Energy,
[ Water
I inputs
Home
Construction
Energy,
Water
inputs
Home Use
(Occupancy)
Energy,
Water
inputs
Home
Demolition/
Deconstruction
Energy,
Water
inputs
C&D Material
Disposal
Transportation
Emissions to Air, Water, and Land
Impacts to Environmental State and Receptors
Source: Adapted from EPA (2009)
Construction of a single-family home includes the delivery and installation of a variety of
materials. For example, construction could include pouring a concrete foundation or slab; framing
with lumber and engineered wood products; constructing exterior elements including the roof,
siding, windows, and doors; installing electrical, plumbing and other systems; finishing the
interior with floors, walls, carpet, cabinets and trim; and installing appliances. During
construction the builder will use natural resources, such as petroleum and electricity to power
equipment, and the construction activity could generate "emissions" in the form of pollution and
-------
waste.30 These emissions translate into impacts to the environmental state (e.g., contaminated air
or water) and impacts to receptors (e.g., health effects, ecosystem degradation).
In Figure 1-1, resource withdrawals (i.e., energy and water inputs) and emissions are represented
by the dotted arrows entering and exiting the box labeled "home construction." Material flows,
which in this case represent materials, products, and services delivered to the job site—are
represented by the solid arrows entering this box.
More traditional perspectives on the residential construction sector would characterize the
resource use and emissions associated with home construction as only those directly used and
created by the construction activity, respectively—i.e., the arrows directing entering and exiting
the "home design and construction" box. LCA, on the other hand, looks at the resources used and
emissions associated with the "supply chain" of materials, products, and services used to build the
home, which includes emissions generated in order to extract, manufacture, and deliver these
materials, products and services to the job site.
For example, whereas a more traditional view would suggest that installation of kitchen cabinets
generates a limited scope of emissions (e.g., to run power saws to cut trim for the cabinets), a life
cycle view would consider a much broader scope. In LCA, the scope considers all of the
emissions generated in the cabinet supply chain. These "upstream" emissions would include those
associated with harvesting timber, milling, assembling the cabinets, and delivering the cabinets to
the job site, including emissions associated with transportation during all of these steps. A similar
view would apply to the resources used to manufacture and deliver the cabinets. LCA looks at all
of the materials, products, and services used to build the home—the "direct inputs" to the
construction—and conducts a similar analysis of all of the upstream resource withdrawals and
emissions associated with these inputs.
In addition to assessing the impacts associated with manufacturing, delivering, and installing
home components, LCA assesses the resources used and emissions associated with the use and
end-of-life of those components, where the latter could include reuse, recycling, or disposal. For
example, if during the life of a home, the kitchen cabinets were replaced, LCA would consider
the emissions associated with removing and disposing of the old cabinets and the emissions
associated with manufacturing, delivering, and installing the new cabinets in the home. If the
cabinets were simply refinished, LCA would consider the emissions associated with stripping the
original finish and applying a new finish. This could include the stripping waste and upstream
emissions associated with the chemicals used to strip the finish as well as the upstream emissions
associated with the new finish.
In this way, LCA attempts to characterize the full impact of a product system Environmental
emissions and natural resource withdrawals quantified using LCA represent the environmental
pressures created by the consumption of a product system. These environmental pressures result
in changes in environmental state and eventually result in impacts to receptors, which can be
30 In this report and in LCA in general, the term "emissions" is used generally to describe the release of
material back to the environment via air emissions, discharges to water, disposal of waste on land, etc.
-------
measured in terms such as human health, ecosystem health, and natural resources degradation.
LCA uses "characterization models" to quantify the relative environmental impact of different
environmental pressures. For example, the impact of greenhouse gas (GHG) emissions is
quantified based on the radiative forcing of GHGs, known as their Global Warming Potential
(GWP).31
The use of characterization models is particularly important when assessing the life cycle impacts
of a complex product system like the single-family home. By expressing impacts using a common
metric (e.g., GWP), direct and upstream impacts can be summed across disparate materials,
products, and services. For example, the use of the radiative forcing approach allows for
summing the impacts from emissions associated with the timber extraction, milling, and delivery
of original and replacement kitchen cabinets, emissions associated with the original cabinet
finish, stripping chemicals, and new finish, transportation of removed cabinets for processing or
disposal, etc. These summed impacts represent the "embodied" GWP impacts associated with
kitchen cabinets.
1.2.2 LCA Alternatives
To provide a national, economy-wide strategic view of the environmental impacts associated with
materials, products, and services consumed in the U.S., an input-output life cycle analysis (I-O
LCA) approach was used, but supplemented with additional information to address use and end-
of-life phases and help quantify the potential for avoided impacts.
A number of methods are used for conducting LCA. They include "process" LCA, input-output
LCA, and hybrids of these methods. "Process," or "bottom-up," LCA is performed by gathering
and analyzing process-specific data on inputs (resources, materials, goods and services) and
outputs (products and emissions) of the target product system over its life cycle. An alternative to
process LCA is input-output life cycle analysis (I-O LCA). I-O LCA incorporates detailed data
describing the economic transactions between industries within an economy. In the U.S., these
data are available through BEA and are used, for example, by the Federal Reserve to formulate
monetary policy and the U.S. Government to formulate fiscal policy (DOC, 2006).
A reasonably complex product system can involve several hundred inputs and outputs,
particularly when viewed from a life cycle perspective, which includes all upstream supply chain
processes and associated resource withdrawals and emissions. Collecting data on each input and
output is a challenge and leads to a long-standing issue in process LCA known as the "truncation
problem" (Lave et al., 1995; Joshi, 1999; Lenzen, 2001; Suh and Huppes, 2002; Suh et al., 2004;
Suh and Huppes, 2005). Given the economy-wide scope of the I-O data, I-O LCA results in
31 Radiative forcing is the change in the balance between solar radiation entering the atmosphere and the
Earth's radiation going out. On average, a positive radiative forcing tends to warm the surface of the Earth
while negative forcing tends to cool the surface. Greenhouse gases have a positive radiative forcing
because they absorb and emit heat (http://www.epa.gov/climatechange/science/recentac.htmlX For a more
detailed technical definition, including practical issues with this definition, see IPCC (2001), Chapter 6.
-------
practically no truncation and is capable of characterizing inputs and impacts associated with
complex and variable product systems.
In addition, where there is great variation among methods used in a product system, it can be
difficult to draw general conclusions based on a limited set of process LCAs. For example,
adjustments would need to be made to generalize the results of a process LCA that assumes one
type of residential building construction to the full range of construction methods actually used. I-
O LCA accounts for this variation. However, as a trade-off, the economic I-O data used in I-O
LCA is generally more aggregated than is necessary to hone in on specific issues or mitigating
actions. Also, I-O LCA focuses on impacts associated with delivering a product to the consumer
and does not explicitly address use and disposal phases associated with a product system.
The limitations of I-O LCA can be addressed by using multiple perspectives and focused supply
chain analyses and by using hybrid approaches that selectively integrate within the I-O LCA
model process-specific data for key inputs and processes (Suh et al., 2004). Process LCA and
input-output LCA share a common analytical approach and, when integrated thoughtfully (e.g.,
where the interfaces between the models use consistent product definitions, the models use the
same data sources or sources of similar quality, etc.), they are complementary. Combining these
approaches can improve the quality of the analysis.
Given the objectives of the analysis of life cycle impacts associated with single-family homes, an
I-O LCA approach was used, employing multiple perspectives and focused supply chain analyses,
supplemented with additional information to address use and end-of-life phases and help quantify
the potential for avoided impacts. I-O LCA provides a national, economy-wide strategic view of
the environmental impacts associated with product systems and has been used in the U.S. and
Europe for similar purposes. The specific methodology used and the results of the analyses are
described in the following sections.
10
-------
2. LIFE CYCLE ANALYSIS METHODOLOGY
2.1. OVERVIEW
An I-O LCA approach was used to develop a national, economy-wide strategic view of the life
cycle environmental impacts associated with single-family homes. This method focused on
identification and analysis of top-ranked supply chain processes, materials, products, and services
used in the pre-occupancy, occupancy and post-occupancy phases of single-family homes and the
potential for avoiding impacts through reductions in material and resource intensity. The analysis
did not attempt to assess the effects of unit- or site-level changes in residential building methods.
Rather, it was used to develop insights into where such additional analyses could best be focused.
It also provides a method for scaling-up the results of site- or unit-focused analyses to evaluate
their potential to have a nationally significant impact.
The analysis consisted of the following steps:
• Identification and analysis of top-ranked supply chain processes, materials, products, and
services:
- Sources were researched and data were collected regarding occupancy and post-
occupancy phases of single-family homes; data were integrated with I-O data to
support the analysis of the full life cycle of single-family homes.
- I-O LCA of residential 1 -unit structures were conducted using input and output
contribution analysis methods, where impacts were characterized using the 17
environmental impact categories used in the 2020 Vision Relative Ranking Analysis
(EPA, 2009).
- A vector analysis was used to rank supply chain processes, materials, products, and
services based on their relative contributions to the overall life cycle impacts
associated with single-family homes.
- Supplemental, focused output contribution analyses were conducted to identify
supply chains processes contributing most significantly to the life cycle impacts
associated with selected materials, products and services.
• Avoided impacts analysis:
- Results of the I-O LCA, supplemental output contribution analyses, and vector
analyses were reviewed and hypothetical scenarios for avoided impacts were
identified based on their potential to reduce material and resource intensity and/or
illustrate the range of policy actions available to address the environmental footprint
of single-family homes.
- Supplemental data were collected regarding key determinants of avoided impacts
(e.g., recycling rates, energy consumption associated with recycling, etc.) and were
11
-------
integrated with the pre-occupancy, occupancy, and post-occupancy data to support
analysis of the overall avoided life cycle impacts.
- I-O LCA was conducted for each of the scenarios and the potential for avoided
impacts was quantified.
Additional information regarding the LCA methodologies used to identify and analyze top-ranked
supply chain processes, materials, products, and services is presented in the remainder of this
section. Sections 3 and 4 present the results of the input and output life cycle impact analyses and
Section 5 describes the methodology and results of the avoided impacts analysis.
2.2. I-O LCA AND CONTRIBUTION ANALYSIS
At the heart of the analysis is the I-O model used to characterize material flows throughout the
life cycle of the single-family home, including flows associated with the pre-occupancy,
occupancy, and post-occupancy phases of the home. These flows form the structure by which
emissions and impacts are characterized through the supply chain processes associated with
single-family homes. This section reviews the methods used to construct the basic I-O model,
including defining the system scope and boundaries, specifying impacts of interest, and
incorporating supplemental use and end-of-life data.
2.2.1 Scope and System Boundary
The life cycle of a single-family home encompasses the following phases:
• Pre-occupancy phase - This phase includes all inputs to the construction of a single-
family home (e.g., framing lumber, windows and doors, cabinets and carpets), including
all upstream supply-chain processes that provide inputs (e.g., forestry and milling, glass
and synthetic fibers manufacturing, transportation) to residential building construction. It
also includes on-site activities during the residential building construction, capturing the
energy and other resource inputs required to construct the building, install components,
etc. and the associated emissions.
• Occupancy phase - The use, or occupancy phase, includes all resources and materials
used in the components of the home (e.g., heating systems, plumbing fixtures, kitchen
and laundry appliances) and to maintain the structure and components, including repairs
and renovations. It also includes all upstream supply-chain processes associated with
these inputs (e.g., electricity generation, replacement cabinet manufacturing) and
emissions associated with the use and maintenance of the home.
• Post-occupancy phase - This phase includes building demolition and/or deconstruction.
It includes the C&D materials, where those materials that are disposed of are considered
"waste" and those that are recycled or reused are considered "products" of this phase. It
also includes the upstream supply-chain processes that provide inputs (e.g., demolition
equipment, energy) to demolish or deconstruct the home and the emissions and waste
generated by this on-site activity.
12
-------
Figure 2-1 illustrates the scope and system boundaries associated with each of these phases.
Combined, these represent the overall scope and system boundary of the life cycle of a single-
family home considered in this analysis.
f All upstream supply chain
Raw Material
Services
Energy
Manufacturing
V Pre-Occupancy Phase J
f All upstream supply chain
Raw Material
Services
Energy
Manufacturing
Occupancy Phase J
f All upstream supply chain
Raw Material
Services
Energy
Manufacturing
Services
Residential
building
end-of-life
Post-Occupancy Phase )
Figure 2-1. The scope of the analysis: system boundary
2.2.2 Impact Categories
The 17 impact categories used in the 2020 Vision Relative Ranking Analysis were used to
conduct this analysis. These include 13 environmental impact categories evaluated using the
CML32 characterization models incorporated in the Comprehensive Environmental Data Archive
(CEDA)33 and four additional categories addressing material use and waste and resource
consumption. Table 2-1 lists the environmental impact categories used in this study. Detailed
descriptions of each impact category are included in Appendix Bl.
32 Leiden University, Institute of Environmental Sciences (Centrum voor Milieuwetenschappen, CML).
33 Characterization of the 13 environmental impact categories (the 17 categories used in this analysis
exclusive of energy and water consumption, material input and waste) is based on the characterization
models developed by the Leiden University Institute for Environmental Sciences (CML). See Suh (2004)
and Guinee et al. (2002).
13
-------
Table 2-1
Impact Categories and Units Used in This Study*
Impact category Units
Abiotic depletion potential (ADP) kg antimony eq.
Land use competition (LUC) million nf*yr
Global warming potential (GWP) kg CO2 eq.
Stratospheric ozone depletion potential (ODP) kg CFC-11 eq.
Human toxicity potential (HIP) kg 1,4-dichlorobenzene eq.
Freshwater aquatic ecotoxicity potential (FAETP) kg 1,4-dichlorobenzene eq.
Marine aquatic ecotoxicity potential (MAETP) niton 1,4-dichlorobenzene eq.
Terrestrial ecotoxicity potential (TETP) kg 1,4-dichlorobenzene eq.
Freshwater sediment ecotoxicity potential (FSETP) niton 1,4-dichlorobenzene eq.
Marine sediment ecotoxicity potential (MSETP) kg 1,4-dichlorobenzene eq.
Photochemical ozone creation potential (POCP) kg ethylene eq.
Acidification potential (AP) kg SCh eq.
Eutrophication potential (EP) kg PO4 eq.
Energy consumption (EC) million BTU
Water consumption (WC) thousand gallons
Material input (MIL) niton
Waste (WST) niton
* See Appendix B1 for definitions of impact categories.
2.2.3 LCA Methodology: Contribution Analysis
Based on the objectives of the analysis, a contribution analysis was conducted to better
understand the sources of significant life cycle impact associated with single-family homes and
help identify strategic opportunities for reducing or avoiding these impacts. Contribution analysis
examines the relative contributions of different inputs to a product system, including direct inputs
and upstream supply chain processes, to the overall life cycle impact associated with the product
system In this way, contribution analysis can highlight those inputs and supply chain processes
that contribute most significantly to the overall impact of single-family homes and, thus, can
provide useful insights for developing strategic actions to address these impacts.
One of the hallmarks of I-O LCA is its ability to support analysis from multiple perspectives once
the fundamental relationships among material flows, emissions, and impacts have been defined.
Taking advantage of this attribute, two types of contribution analysis were completed for this
study: 1) input contribution analysis and 2) output contribution analysis. Input contribution
analysis analyzes the relative contribution of direct inputs to the overall life cycle impacts of the
product system Output contribution analysis, on the other hand, associates impacts with their
original source in the upstream supply chain of the product system. The two approaches offer
different ways to disaggregate the overall life cycle impact and can provide different insights into
sources of impact and approaches for addressing impact.
For the single-family home "product system," input contribution analysis includes impact
estimates and resource withdrawals associated with each of the "direct inputs" to the home. This
14
-------
includes an estimate of the impacts and resource use associated with each of the materials and
products delivered to the job site (pre-occupancy phase) and/or delivered to the home as
replacements (occupancy phase). It also includes each of the services provided in support of the
home construction and/or renovation and work completed on the job site and/or during the
renovation. These include, for example, the impacts associated with wood kitchen cabinets
delivered to the site plus impacts associated with running the machinery to install the cabinets in
the home (e.g., to run power saws to cut trim for the cabinets).
In the results of the input contribution analyses, the impacts and resource use associated with each
direct input are a compilation of all of the impacts and resources embodied in those inputs. For
example, in the case of wood kitchen cabinets, all of the impacts associated with the upstream
supply chain processes used to manufacture and deliver the cabinets to the job site would roll-up
to the wood kitchen cabinet product category (BEA code 200502). This would include, for
example, all of the impacts and resources used in association with harvesting timber, milling,
assembling the cabinets, and transporting the cabinets to the job site.
In contrast, the output contribution analysis disaggregates, or separates out, the impacts and
resource withdrawals to their original source in the supply chain. In the case of wood kitchen
cabinets, all of the impacts upstream of the cabinet manufacturer would be disaggregated—e.g.,
impacts associated with logging would be included in BEA category 200100, logging; impacts
associated with transporting the logs to planning mills would be included in BEA category
650301, trucking and courier services; impacts associated with sawing/planing the logs would be
included under BEA category 200200, sawmills and planing mills, etc. In the results of the output
contribution analysis, the only impacts associated with the wood kitchen cabinets category would
be those associated with emissions generated and resources used during the actual cabinet
manufacturing operations.
In a product system as complex as a single-family home, some upstream supply chain processes
will be associated with more than one direct input. For example, sawmills could be a process in
the supply chain for both framing lumber and wood kitchen cabinets. In the input contribution
analysis, the impacts associated with operating the sawmill would be distributed to framing
lumber and kitchen cabinets (and other products associated with sawmills) in proportion to the
contribution of these direct inputs to the overall home construction. In the output contribution
analysis, these impacts would not be disaggregated but, rather, would be reported together in
association with the sawmill category.
Figure 2-2 illustrates these two approaches to contribution analysis and the relationships of input
and output contribution analysis to total life cycle impacts associated with a product system
This dual approach to the analysis was selected to help elucidate the possible effects of different
policy options and/or external trends on the overall life cycle impact associated with single-
family homes. Input contribution analysis provides a perspective on materials selection in single-
family home construction, use, and end-of-life and highlights those materials used by the
residential construction industry that embody the greatest impacts. Output contribution analysis,
15
-------
on the other hand, highlights how changes in a supply-chain process, (e.g. emissions associated
Figure 2-2
Illustration of Input and Output Contribution Analyses
Values calculated
using Input
Contribution
Analysis
Values calculated using Output
Contribution Analysis
1
i
Logging
i
Sawmills
i
Logging
Sawmills
r 1
Manufacturing of
kitchen cabinets
used in single
family houses
1
Logging
;
-
Sawmills
r i
Manufacturing of
framing lumber
used in single
family houses
Sum of logging impacts
associated with products
1 used in single family houses
*
Sum of sawmill impacts
associated with products
*
Manufacturing of
other wood-related
products used in
single family
hni RPR
Sum of manufacturing
impacts associated with
kitchen cabinets, framing
lumber and other wood-
related products used in
single family houses
Sum of embodied Sum of embodied Sum of embodied Total life cycle impacts
impacts associated impacts associated impacts associated associated with kitchen
with kitchen * with framing lumber * with other wood- ^ cabinets, framing lumber
cabinets used in used in single family related products and other wood-related
single family houses used in single family products used in single
houses
houses family houses
with sawmill operations), could affect the life cycle impacts associated with single-family homes.
2.2.4 Defining "Direct" and "Indirect" Impacts
As discussed above, the input contribution analysis of, for example, the pre-occupancy phase of a
single-family home includes impact estimates and resource withdrawals associated with each of
the materials and products delivered to the job site and each of the services provided in support of
the home construction. The output contribution analysis disaggregates these impacts and resource
withdrawals to their original source in the supply chain.
The I-O LCA described herein labels impacts and resource withdrawals that take place during the
construction or use of the home as "direct" impacts or resource withdrawals. Impacts and
resource withdrawals associated with upstream supply chain processes are labeled "indirect." For
example, sediment runoff from the site during the construction of a home could result in
eutrophication impacts, which would be classified as "direct" impacts in this analysis. On the
other hand, eutrophication impacts embodied in ready-mixed concrete used to build the
foundation for the home (e.g., impacts associated with nitrogen-containing compounds emitted
during cement production) would be considered "indirect."34
34 Eutrophication describes a condition where nutrient enrichment causes shifts in species composition and
elevated biomass production in aquatic and terrestrial ecosystems (see Appendix Bl). Run-off from
16
-------
Impacts associated with some direct inputs, are represented in the I-O LCA in terms of both an
"environmental impact" and a "resource withdrawal." For example, when diesel fuel is
combusted in construction vehicles on-site, the I-O LCA accounts for this in terms of both the
environmental impact associated with combustion emissions and energy consumption, which is a
resource withdrawal. In addition, to prevent double-counting the I-O LCA measures energy
consumption based on the point of combustion. Diesel fuel combusted in construction vehicles on
site is considered "direct" energy consumption. The combustion of coal and other fossil fuels to
generate electricity that is used during construction is considered "indirect" energy consumption.
The consumption of these fossil fuels is embodied in the electric services input to single-family
home construction. For additional information and figures illustrating the relationships among the
direct and indirect impacts in the pre-occupancy and occupancy phases, see Appendix B2.
2.3 VECTOR ANALYSIS
The vector analysis approach developed for the 2020 Vision Relative Ranking Analysis was used
to rank the supply chain processes, materials, products and services based on their contributions
to the overall life cycle impacts of single-family homes. Vector analysis provides a transparent
approach for characterizing impacts across multiple and disparate impact categories without
embedded weighting. It tends to highlight those supply chain processes, materials, products and
services whose impacts differ significantly from the average across one or more impact categories
and provides readily available information regarding the impact categories driving the ranking.
A more detailed discussion of the vector analysis methodology and rationale for each of these
steps is included in EPA (2009). An overview of how the vector analysis was used in this analysis
of single-family homes is presented below. Appendix C provides additional technical detail, an
applied example of vector analysis in the context of this LCA as well as a brief discussion of
strengths and weaknesses of the vector analysis approach.
2.3.1 Pre-Occupancy
For the purpose of assessing the life cycle impacts associated with single-family homes, separate
vector analyses were conducted on the input contribution analysis results and output contribution
analysis results for the pre-occupancy phase. The following steps were employed:
• CEDA output data (see section 2.5.1) were compiled for each of the supply chain
processes, materials, products, and services and for each impact category. Supply chain
processes, materials, products, and services that did not indicate contribution to life cycle
impacts associated with the pre-occupancy phase of single-family homes were eliminated
from the analysis.
construction sites can contain nitrogen that can affect the nutrient balance in nearby water bodies. It can
also result in sedimentation, which can affect the bio mass balance by affecting sunlight penetration of the
water column. Emissions of nitrogen-containing compounds during cement production, such as nitrogen
oxides (NOX) and ammonia (NH3) can affect the nitrogen load in terrestrial and aquatic ecosystems.
17
-------
• The average (mean value) for each criterion was computed and subtracted from the
criterion value for each of the supply chain processes, materials, products, and services
retained in the analysis, the standard deviation for each impact category was calculated,
and the mean-centered values were normalized by the standard deviation.
• Vector magnitudes were calculated by taking a square root of the sum of the individual
standard deviations squared; vector magnitudes were calculated as the basis for ranking
supply chain processes, materials, products and services.
Vector analyses were conducted for all 17 impacts - the 13 environmental impact categories from
the Comprehensive Environmental Data Archive (CEDA) and four additional categories
addressing material use and waste and resource consumption. In addition, for the pre-occupancy
phase, vector analyses were also conducted for the following groupings of impacts:
1. Natural Resources and Land Use - waste (WST), abiotic depletion potential (ADP), energy
consumption (EC), water consumption (WC), land use competition (LUC), and material input
(MTL);
2. Toxicity - human toxicity potential (HTP), freshwater aquatic ecotoxicity potential (FAETP),
marine aquatic ecotoxicity potential (MAETP), terrestrial ecotoxicity potential (TETP),
freshwater sediment ecotoxicity potential (FSETP), and marine sediment ecotoxicity potential
(MSETP); and
3. Pollution Impacts - stratospheric ozone depletion potential (ODP), global warming potential
(GWP), acidification potential (AP), euthrophication potential (EP), and photochemical
ozone creation potential (POCP).
2.3.2 Occupancy
For the occupancy phase, 13 specific products/materials and one "other" material/product
category were considered in the analysis of life cycle impacts associated with replacement of
home components during the occupancy phase (see Section 2.5). In addition, the occupancy-
phase analysis considered overall life cycle impacts associated with electric services, natural gas
distribution, and petroleum refining used during occupancy. Therefore, the input contribution
analysis of the occupancy phase considered the embodied impacts associated with these 17 direct
inputs. The output contribution analysis, on the other hand, disaggregated these impacts to
upstream supply chain processes, and indicated that 450 upstream supply chain processes are
associated with the production and delivery of these 17 occupancy-phase inputs.
Vector analysis is an appropriate methodology for providing insights when the array of inputs and
impacts is too broad to be understood using simpler techniques. The output contribution analysis
for the occupancy phase of a single-family home generated 7,650 impact estimates (450 supply
chain processes over 17 impact categories). Therefore, the full vector analysis methodology, as
described above for the pre-occupancy phase, was used to analyze the occupancy-phase output
contribution results.
18
-------
The input contribution analysis generated 289 impact estimates (17 supply chain processes over
17 impact categories). The initial vector analysis of these results suggested that certain supply
chain processes consistently ranked other than the rest across impact categories and that the
conditions under which vector analysis works most effectively in this context were not met.35
Therefore, for the input contribution analysis of the occupancy phase, the contribution of each
input to the life cycle impacts associated with this phase was considered on a factor-by-factor
basis.
2.3.3 Post-Occupancy
For the inputs used in the post-occupancy phase, neither the input contribution analysis nor the
vector analysis was conducted. Existing literature suggests that the impacts of inputs used in the
post-occupancy phase represent a relatively small percentage of the overall life cycle impacts
associated with single-family homes (Ramesh et el., 2010; Oregon DEQ, 2010). Based on this
and the limited scope of impacts considered, a separate output contribution analysis also was not
completed for the processes used in the post-occupancy phase. Post-occupancy phase impacts
were only included in the overall analysis of life cycle impacts associated with single-family
homes (see Section 3.2). For more detailed explanation of the assumptions associated with the
post-occupancy phase, see Section 2.5.5.
2.4 SUPPLEMENTAL CONTRIBUTION ANALYSIS OF SELECTED DIRECT
INPUTS
The results of the vector analysis of the input contribution results were reviewed to identify
highly ranked direct inputs to single-family homes for further review. Supplemental contribution
analyses were conducted to identify the "hotspots" in the supply chains of these direct inputs,
where "hotspots" were defined as the supply chain processes contributing most significantly to
the overall life cycle impact of the direct input.
The data sources and methodologies used to analyze the life cycle impacts associated with these
inputs were the same as those used to analyze life cycle impacts associated with single-family
homes. See Sections 2.2.3 through 2.5 for more detailed descriptions of applicable data sources
and methodologies.
35 As part of the 2020 Vision Relative Ranking Analysis, the distributions of impact estimates about the
mean for each impact criterion were analyzed to evaluate whether one or more criteria imparted an
inordinate influence on the overall vector ranking results (EPA, 2009, pp. 19-20). The analysis indicated
that the estimates within each impact category tended to cluster around the mean impact estimate and that
the materials, products, and services that differed most significantly from the mean did so in a positive
direction (i.e., estimated impact was much greater than the average). This allows for the efficient
interpretation of vector analysis results, as the criteria driving relatively high rankings represent criteria for
which the material, product, or service is relatively more impactful. For the occupancy-phase input
contribution analysis, impact estimates were more normally distributed around the mean, and, thus, the
conditions that lend clarity to the vector analysis approach in multiple dimensions were violated.
19
-------
2.5 DATA SOURCES
The contribution analyses were conducted using the environmentally extended input-output
databases incorporated in CEDA, supplemented with additional data to incorporate material use
and waste impact categories and occupancy and post-occupancy phases of single-family homes.
2.5.1 Comprehensive Environmental Data Archive (CEDA)
CEDA covers a comprehensive list of environmental interventions36 for a range of natural
resource types (e.g., fossil fuels, water, metals ores and minerals), and emissions of a range of
substances to air, water and soil.37 CEDA quantifies natural resource use and environmental
emissions of products throughout their pre-consumer life cycles by connecting input-output
tables, which represent the entire supply-chain network of an economy, with a comprehensive list
of environmental interventions. The U.S. version of CEDA contains over 3 million data points,
distilled from raw data sources containing tens of millions of data points using a consistent and
rigorous quality control process (Suh 2004).
2.5.2 Supplemental Material Use and Waste Data
The CEDA databases were supplemented with material use and waste data developed for the
2020 Vision Relative Ranking Analysis using World Resources Institute (WRI) Materials Flow
Analysis (MFA) data. MFA data were developed by WRI as a comprehensive estimation of
material flows for over 160 primary materials consumed in the U.S. economy from 1975 through
2000, covering four principal sectors: agriculture, forestry, non-renewable organic materials (e.g.,
fossil fuels), and metals and minerals (WRI 2008). For the 2020 Vision Relative Ranking
Analysis, material waste was defined to be consistent with the direct process output (DPO)
measure used by WRI, which includes all materials that are consumed in the U.S. economy and
"exit" (e.g., through disposal in a landfill) within 30 years after entry.38 The WRI MFA data were
captured in the 2020 Vision Relative Ranking Analyses by cross-walking the WRI material
classification system with the BEA-defmed industries included in CEDA (EPA 2009).
2.5.3 Occupancy-phase Energy Use, Water Consumption, and GHG Emissions
Data
Energy use, water consumption, and GHG emissions during the occupancy phase of residential
homes were estimated based on information available through the U.S. Department of Energy.
36 In the context of CEDA and similar LCA tools, the term "environmental intervention" is a general term
used to capture a range of interactions between humans and the environment, including resource extraction,
land use, and emissions to air, water, and land. See ISO (1997).
37 For additional detail, see Suh (2004), Appendix B.
38 DPO is equal to direct material consumption (DMC), which is used as the measure of "material use," less
material that remains in the economy for over 30 years, less material that is recycled (WRI 2008).
20
-------
(DOE). The DOE Buildings Energy Data Book (DOE 2010) provides data regarding energy use
and GHG emissions from 1980 through 2008 and projects future energy use and GHG emissions
through 2035. The following assumptions were made to estimate the energy use, water
consumption, and GHG emissions associated with homes built in the reference year of 1998
based on the DOE data and projections:
• Energy use - DOE projects that residential homes in the U.S. will consume a quintillion
Btu of energy over the 50-year period from 1980 to 2030 (DOE 201 la, Table 2.1.1). In
1998, single-family homes newly built in that year comprised 1.12% of the total housing
stock (DOE 201 la Tables 2.2.1 and 2.5.1). Based on this proportion, 1.12% of the total
projected energy consumption, or 11 quadrillion Btu, was ascribed to the single-family
homes built in 1998. An emissions factor was used to derive direct emissions and 1998
energy price data were used to monetize energy use. CEDA was then applied to calculate
indirect emissions associated with energy use during the home occupancy phase.
• Water consumption - DOE data support two ways to estimate total water consumption by
residential homes: (1) using time-series survey data and (2) based on per-capita water
consumption per use categories (DOE 201 la, Tables 8.2.1 and 8.2.2). Using these
approaches total water use by residential homes for the 50-year period from 1985-2035 is
estimated to be 5.7 and 5.9 trillion gallons, respectively. For the purpose of this analysis,
an average of the two numbers, or 5.8 trillion gallons was used. Consistent with the
approach for energy use, 1.12% of this total was attributed to homes built in 1998.
• GHG emissions -DOE projects that residential homes will be responsible for 56 billion
metric tons of CO26 GHG emissions during the 50-year period from 1985 to 2035. For
the purposes of this analysis, it was assumed that the homes built in 1998 produce
average amount of GHGs relative to the overall housing stock during this period. Based
on the approach used above, the life-time GHG emission from the single-family
residential homes built in 1998 was estimated to be 1.12% of 56 billion metric tons, or
628 million metric tons of CO26.
These estimates are rough and are subject to uncertainty due to, for example, trends in technology
and efficiency in the future. However, these estimates are considered adequate to help rank-order
supply-chain processes, materials, products and services and quantify avoided impacts potential
for possible, more detailed analysis.
2.5.4 Occupancy Phase Material Replacement Data
Life cycle impacts associated with the materials replaced during the occupancy phase of a
residential home were estimated by incorporating data regarding the types and value of materials
replaced into the CEDA database. This approach was used to take advantage of the computing
capabilities of CEDA and to maintain maximum consistency between pre-occupancy and
occupancy LCA results.
21
-------
A number of statistics and reports were reviewed to develop estimates of replacement
requirements during the occupancy phase of a single-family home. Among others, the Oregon
DEQ has conducted a comprehensive LCA study providing valuable information on the types and
quantities of materials replaced during this phase (Oregon DEQ, 2010). Given the quality of the
Oregon study, the data were used as the basis for this present study with modifications to
monetize the data for use in CEDA and to account for uncertainties in the use of these data for a
national-scale LCA, as follows:
• The scope of material replacements was limited to the following 13 specific products
commonly replaced or used in the renovation of a single-family home over its life span
and/or for which adequate data were available: carpeting, linoleum flooring, asphalt
shingle roofing, glass fiber insulation, drywall, doors and windows, plastics, lumber,
hardware, electrical fixtures, foundation, paints, and wood shingle siding.
• In order to utilize I-O LCA approach, physical unit data for replacements were monetized
using the price data provided in the Oregon report. The original installation data for
building materials in an average 1 -unit residential building in the Oregon State study
were converted into monetary units. The unit cost data were scaled up to provide
nationwide estimates based on the number of homes built in 1998. Monetary conversions
are summarized in Appendix Al.
• In 1998, new single-family homes cost $184 billion according to the BEA 1998 input-
output data Using this figure and the BEA input-output data, nationwide cost estimates
for each replacement item were derived. These estimates were compared with the scaled -
up figures from the Oregon study, adjusting inflation. In general, both sets of figures
were in the same order of magnitude, though reasonably significant discrepancies were
observed for some items, most notably carpet—figures based on the Oregon study were
more than 10 times higher than those based on I-O data—and paint— estimates based on
the Oregon study were less than 10% of the I-O-derived estimates.
• To further evaluate the replacement assumptions generated using the Oregon data and
address these apparent discrepancies, a similar study done by Harvard University (2009)
was reviewed. Figures from the Harvard University study are summarized in Appendix
A2. The Harvard University figures also indicated that the scaled-up carpet replacement
figures from the Oregon state study might be an overestimation; there was no comparable
data on paint in the Harvard University study. Based on this, the monetary value of carpet
replacement was estimated for this study as the ratio between the value derived from
BEA I-O data and the scaled-up Oregon study for original installation. The Oregon
assumptions regarding carpet replacement were not used directly.
• For the purposes of estimating waste associated with material replacement, it was
assumed that there is one-to-one correspondence between the amount of materials
replaced and the amount of waste generated due to the replacement during the occupancy
phase.
22
-------
Overall, the data used as the basis for this LCA suggest the costs of replacements over the
lifespan of a single-family home built in 1998 range from $122 billion (Harvard University study)
to $208 billion USD (Oregon state study), in $1998. Given that total new residential building
construction in 1998 cost $184 billion ($1998), replacements over the lifespan of residential
buildings are estimated to be comparable to the cost of new residential buildings for the purposes
of this study. Appendix Al summarizes the itemized replacement costs derived from the Oregon
State study with modifications based on review of the BEAI-O data and Harvard University
study.
2.5.5 Post-Occupancy Phase Data
For the purpose of the analysis, the "end-of-life" of residential structures was defined as the point
when buildings are demolished or deconstructed. Based on information available in the literature,
impacts associated with the post-occupancy phase of residential homes are small relative to the
overall life cycle impacts associated with a single-family home. Of the post-occupancy impacts,
those associated with energy consumption, combustion-related emissions and waste generation
are most significant (Sara et al., 2001; Boyano Larriba and Wolf, 2010). Therefore, the scope of
the post-occupancy impacts analysis was limited to these factors.
Post-occupancy impacts were calculated using a number of different sources. Information
regarding GHG emissions associated with the demolition phase was adopted from the Oregon
DEQ (2010) study. Oregon DEQ (2010) estimates that demolition of an average residential home
generates about 600 kg of CO2-eq. GHG emissions - this number includes emissions of carbon
dioxide, carbon monoxide, dinitrogen monoxide and sulfur hexafluoride from diesel equipment
operation and use of electricity, but excludes worker commuting. The GHG emissions associated
with the landfilling of organic materials, e.g., wood, have not been allocated to the post-
occupancy phase in this study, and consequently, the GWP environmental impact of the post-
occupancy phase is somewhat underrepresented. If we assume a 49.5% contribution of wood to
the C&D waste from residential demolition sites,39 and 1.6 mton CO2-eq per mton of waste,40 the
GWP associated with wood waste emissions in landfills are 39,600 kg CO2-eq. Allocating this
GWP impact from wood waste emissions to the post-occupancy phase would have raised its
contribution to the life cycle GWP impacts associated with single-family homes from .0007% to
4.3%.
Energy consumption data were derived from average diesel fuel consumption associated with the
post-occupancy phase of wood-frame structures in Minnesota and Atlanta, referring to
Winistorfer et al. (2005). Waste generated during the post-occupancy phase was calculated as the
difference between the total life-cycle waste generation per a unit residential home and the
amount of replacement, assuming that replacement generates the same mass amount of wastes
during the occupancy phase. The basic data for life-cycle waste generation and replacement were
39 Table A-13, http://www.epa.gov/wastes/hazard/generation/sqg/cd-rpt.pdf. accessed January 31, 2013
40 Exhibit 6, p.7, http://www.epa.gov/climatechange/waste/downloads/Landfilling.pdf. accessed January
31,2013
23
-------
derived from Oregon DEQ (2010), where the replacement volume per standard house was scaled
up by multiplying the number of housing units built in 1998 (1.16 million).
24
-------
3. RESULTS: LIFE CYCLE IMPACT ANALYSIS OF DIRECT
INPUTS TO SINGLE-FAMILY HOMES
3.1 OVERVIEW
The following section presents the results of the input contribution analyses of the national
housing stock of single-family homes. Section 3.2 reviews the estimates of overall life cycle
impacts associated with single-family homes, and Section 3.3 disaggregates these impacts based
on the input contribution perspective, summarizing the results of the input contribution analysis.
Section 3.4 presents the more detailed analysis of the supply chain processes contributing most
significantly to the life cycle impacts associated with selected, highly ranked direct inputs
identified using the input contribution analysis.41
3.1.1 About Carpets and Rugs and Cotton42
The input contribution analyses highlighted the contribution of carpet and rugs to the land use
competition, freshwater aquatic ecotoxicity potential, and terrestrial ecotoxicity potential lifecycle
impacts associated with single-family homes. The supplemental analysis for carpets and rugs
highlighted that these impacts were associated with cotton cultivation to produce cotton fibers.
However, the Carpet and Rug Institute shows that carpet fibers used in single-family homes are
dominated by synthetics followed by wool at 0.4%, and does not attribute any content to cotton.43
Similarly, the output contribution analyses, which are presented in Section 4, highlighted the
contribution of cotton as the significant contributor to the life-cycle impacts associated with
single-family homes. Again, this impact was primarily attributed to the assumed consumption of
cotton within the Carpet and Rug Mills industry as a whole. For example, Carpet and Rug Mills
(314110), which indeed does not have any direct cotton input, uses significant textile- related
products such as Textile and Fabric Finishing (313320), Other textile products (314990),
Nonwoven fabric mills (313230), and Narrow fabric mills (313220) that do consume a significant
amount of cotton. Due to the aggregation of non-cotton based and cotton-based products within
these sectors, carpet and rugs endowed contribution from cotton and the embodied impacts
associated with cotton cultivation despite cotton not being their direct input.
41 The material/product category "feed grains" has been removed from the relative ranking results presented
herein. This category tended to be ranked highly based on impacts associated with land use, terrestrial
ecotoxicity, and impacts associated with agricultural run-off (i.e., freshwater aquatic ecotoxicity and
eutrophication). However, it is posited that the contributions of feed grains to single home construction
relate to feeding workers (e.g., via mobile canteens). The relevance of this category to the current analysis
is considered limited and its elimination improved the presentation of results.
42 Input Contribution Analysis, which is presented here, highlighted Carpets and Rugs, and Output
Contribution Analysis, which is presented in Section 4, highlighted Cotton. Considering that both findings
revolve around an assumed cotton input, a common explanation is provided herein.
43 The Carpet & Rug Institute's Carpet Primer indicates that carpet doesn't contain cotton - the majority of
carpet fiber is nylon at 57%, followed by olefm at 36%, polyester at 7% and wool at 0.4%:
http://www.carpet-rug.org/residential-customers/resources/carpet-primer.cfm Accessed October 21, 2011
25
-------
The EPA finds this type of aggregation to be a limitation of the I-O LCA high-level approach and
has attempted to cautiously interpret the findings. In that respect, the EPA dismisses the finding
that in the context of single-family homes, carpets and rugs and cotton contribute significantly to
the land use competition, freshwater aquatic ecotoxicity potential and terrestrial ecotoxicity
potential life-cycle impacts.
The figures in this report will include carpets and rugs and cotton as such are the results of the I-
O LCA, but the discussions associated with the figures will not acknowledge and validate their
contribution to the lifecycle impacts of single-family homes; the EPA finds that such a conclusion
would be flawed.
3.2 OVERALL LIFE CYCLE IMPACT
3.2.1 Total Life Cycle Impacts and Impacts by Phase
Table 3-1 summarizes the results of the I-O life cycle analysis for typical single-family home
built in 1998. The results are broken down in terms of life cycle phase—pre-occupancy,
occupancy, and post-occupancy, as described in Section 2.2.1. The information is also
summarized in Figure 3.1 in terms of the relative contribution of each phase to the overall life
cycle impact of a typical single-family home. Appendix D presents the results of the overall life
cycle analysis broken-down further by phase and locus of impact (i.e., direct or indirect).
The I-O LCA analysis indicates that the majority of life cycle impacts associated with single-
family homes occur during the occupancy phase. This finding holds for all of the measures of
toxicity-related impact and pollution impact and all but one of the measures of land and resource
use impact. The one exception in this last category is material use, where the majority of impact
occurs during the pre-occupancy phase.
The I-O LCA methodology used for this analysis indicates that the life cycle impacts associated
with the post-occupancy phase are relatively insignificant for all but the waste impact category.
This finding reflects the phase boundaries used in the analysis and should not be interpreted to
imply that choices regarding the management of building demolition/deconstruction material
have an insignificant effect on the overall life cycle of a single-family home. Rather, this finding
reflects the fact that far greater inputs (i.e., resources and materials) are consumed during the
construction and use of a single-family home than during its demolition or deconstruction.
The recycling and reuse of C&D waste as input for new single-family home construction or
renovation can offset the use of virgin material and, thus, can contribute to a reduction in the
impacts associated with single-family homes, when this "product category" is viewed in
aggregate. The recycling and reuse of C&D material from one home can decrease the pre-
occupancy phase impacts associated with one or more others. In addition, the recycling and reuse
of C&D material from single-family homes can be reused in a manner that lessens the life cycle
impacts associated with other "product" categories, such as commercial building or highway
construction. For example, Section 5.3 quantifies the potential of the reconstituted wood products
26
-------
from demolished or deconstructed single-family homes to offset environmental impacts of paper
and pulp industries when used to replace a portion of coal needed in paper production. Section 5.3
also explores and documents the types of impacts that can be offset through an increased
processing of carpets and rugs into resin for synthetic materials and ready-mixed concrete into
aggregate for use in road construction.
Table 3-1
Summary of Estimated Life Cycle Impacts of Typical Single-family Homes44
(1998 Basis)
Impact category
Abiotic depletion potential
(ADP)
Land use competition (LUC)
Global warming potential
(GWP)
Stratospheric ozone depletion
potential (OOP)
Human toxicity potential (HTP)
Freshwater aquatic ecotoxicity
potential (FAETP)
Marine aquatic ecotoxicity
potential (MAETP)
Terrestrial ecotoxicity potential
(TETP)
Freshwater sediment
ecotoxicity potential (FSETP)
Marine sediment ecotoxicity
potential (MSETP)
Photochemical ozone creation
potential (POCP)
Acidification potential (AP)
Eutrophication potential (EP)
Energy consumption (EC)
Water consumption (WC)
Material input (MIL)
Waste (WST)46
Units
kg Sn eq.
m2*yr
kg CO2 eq.
kgCFC-lleq.
kgp-DCBeq.
kg p-DCB eq.
niton p-DCB eq.
kgp-DCBeq.
niton p-DCB eq.
kg p-DCB eq.
kg CJli eq.
kg SO2 eq.
kgPO4eq.
106BTU
103 gallons
niton
niton
P re-
Occupancy
500
11,000
140,000
620
16,000
2,600
47,000
3,100
17,000
30,000
90
500
70
1,200
13,000
2,700
120
lated Impact 1
Occupancy
4,700
25,000
760,000
1,100
39,000
5,500
250,000
6,300
84,000
42,000
250
5,000
250
14,000
250,000
1,100
620
Post-
Occupancy
0
0
600
0
0
0
0
0
0
0
0
0
0
20
0
0
50
Total Life
Cycle45
5,200
36,000
900,000
1,800
55,000
8,000
290,000
9,400
100,000
72,000
330
5,500
320
15,000
270,000
3,700
790
44 To understand the relative significance of the life cycle impacts of single-family homes, see the overall
vector magnitude for single-family homes as related to the whole U.S. economy, in the Relative Ranking
Technical Support Document, the appendix to Sustainable Materials Management: The Road Ahead (EPA,
2009).
45 Values across the rows in the table may not add up due to the rounding off to two significant digits.
46 The life cycle waste associated with single-family homes does not equal the life cycle material input for
the following reasons: 1) some material inputs leave the system not as a waste but as something else, and
vice versa (e.g., coal is converted to CO2 and water and is emitted during combustion; less than 10% of
mass is counted as waste); 2) there are losses and additions to urban/industrial stock throughout the supply-
chain that are not counted as waste; 3) imprecisions associated with the methods used to collect economic
and environmental data do not allow for a complete mass balance.
27
-------
Figure 3-1
Contribution of Different Life Cycle Phases of a Typical Single-family Home to
Overall Life Cycle Impact
sn%
7n°/
fin0/
•IflO/
on°/
o
/
•H.C/ t
O "^
o ^
- O -s
^5* C
4
~~
?
(
P°
/
. o<
/
r*
j
/,
/
/
. <
^
/
? •
.#
»*
/.
^
*?
^
^
/
^
^
•^
*
«?
? e
/
/
/
j ^
'fr
/
/
- *
/c
/
/
- c
^
1
^
^
" «S
• Post Occupancy
^ • Occupancy
/
For some impact categories, the estimated occupancy-phase impacts exceed the estimated pre-
occupancy phase impacts by close to an order of magnitude or more. These include the abiotic
depletion potential, marine aquatic ecotoxicity potential, freshwater sediment ecotoxicity
potential and acidification potential impact categories and energy and water consumption. These
impacts are attributable to electric services, and the relative differences in impact estimates for
these and the energy consumption categories likely reflect significantly higher energy
consumption during the home occupancy phase (see Section 3.3.2 for further discussion of
occupancy-phase life cycle impacts).
3.2.2 Locus of Impact: Pre-Occupancy and Occupancy Phases
Figure 3-2 presents a more detailed view of the life cycle impacts associated with the pre-
occupancy and occupancy phases of the typical single-family home. Each of the charts breaks
down the total life cycle impacts shown in Figure 3-1 for the respective phase based on the locus
of impact, direct or indirect, as defined in Section 2.2.4.
28
-------
Figure 3-2
Locus of Impact - Pre-Occupancy and Occupancy Phases
Pre-Occupancy Phase
90%
0% -
1
• Direct Indirect
Occupancy Phase
90%
50%
30%
10%
£//////£//£//&/*
• Direct Indirect
The input contribution analysis indicates that for the pre-occupancy phase the majority of impacts
are indirect - i.e., they are embodied impacts associated with upstream supply chain processes.
This is true for all impact categories with the exception of material input. The material input
category is measured in terms of mass, and construction of single-family homes involves
significant material use on a mass basis, with materials such as sand and gravel, concrete, and
stone being reflected as direct impacts. Other categories of where there are significant direct
impacts include those in the pollution impacts grouping and energy consumption. These likely
reflect on-site energy use, including fuel combustion (e.g., by construction vehicles), and surface
water impacts associated with land disturbance and re-vegetation.
The input contribution analysis for the occupancy phase highlights the direct impacts associated
with the use of the land upon which the home is situated, energy and water consumption, impacts
associated with emissions from fuel combustion, material input associated with replacement
products, and waste. The indirect impacts are associated with the upstream supply chain
processes embodied in energy production and delivery to the home as well as manufacturing and
the delivery of material/product replacements during the occupancy phase of the home. Similar to
the pre-occupancy phase, indirect impacts dominate the total occupancy phase life cycle impacts.
3.2.3 Comparison with Previous Studies
The estimates of overall life cycle impacts produced using the I-O LCA approach described
herein generally agree with the findings of the Oregon DEQ (2010) study. The Oregon study
differed from the present analysis in terms of methodology, system definition, scope (i.e., state-
specific vs. national), measures of impact, data sources, and assumptions. Nonetheless, both
29
-------
indicate that the majority of life cycle impacts associated with single-family homes occur during
the occupancy phase. This agreement between the two analyses holds across measures of abiotic
depletion potential, global warming potential, stratospheric ozone depletion potential, human and
ecological toxicity potentials, photochemical ozone creation potential, acidification potential,
eutrophication potential, energy consumption, and water consumption. Both analyses attribute
these occupancy-phase impacts to energy use and life cycle impacts associated with material
replacement.
In terms of the magnitude of the life cycle impact associated with single-family homes, the results
of the current analysis are also consistent with prior research. For example, the Oregon DEQ
(2010) study reported life cycle GHG emissions of 684,000 kg CO2 eq. and 12,300 million Btu of
primary energy consumption on a per home basis. This national-scale analysis estimates life
cycle GHG emissions of 900,000 kg CCh eq. and life cycle primary energy consumption of
15,000 million Btu per home. Given the differences in the methodologies employed, the
agreement between these estimates is relatively strong.
3.3 INPUT CONTRIBUTION ANALYSIS
Input contribution analysis quantifies the relative contribution of direct inputs to the overall life
cycle impacts associated with a single-family home. This includes estimates of embodied impacts
associated with materials, products, and services used directly in building, renovating, and
demolishing or deconstructing a single-family home. The input contribution analysis was
completed for the pre-occupancy and occupancy phases, as described in Sections 2.2 through 2.5.
The results of the input contribution analysis are summarized below. Detailed results are
presented in Appendix F.
3.3.1 Pre-Occupancy Phase
Figure 3-3 highlights the top ten most highly ranked materials, products, and services used in the
pre-occupancy phase of single-family homes from an input contribution perspective. The analysis
indicates that when all factors are considered equally (no weighting or grouping), a diverse mix of
direct inputs contributes to the overall life cycle impacts of single-family homes. The analysis
highlights building materials (e.g., brick and structural clay tile, ready-mixed concrete,
reconstituted wood products}, more highly engineered products (e.g., miscellaneous plastic
products), and services (e.g., trucking and courier services).
30
-------
Figure 3-3
Highest Ranked Materials, Products, and Services
Full Scope (all impact categories)
Input Contribution Basis - Pre-Occupancy Phase
Brick and structural clay tile
Ready-mixed concrete
Carpets and rugs
Mineral wool
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Trucking and courier services, except...
Reconstituted wood products
Sand and gravel
Motor vehicles and passenger car...
(
) 5 10 15 20 25
Vector Magnitude
Table 3-2 further explores these results by analyzing the impact categories behind the relatively
high rankings developed using the vector analysis approach. The table lists the 10 most highly
ranked direct inputs contributing to the life cycle impacts associated with the pre-occupancy
phase of single-family homes, considering all of the impact categories. The values associated
with each impact category in the table represent the change in vector orientation, in degrees, from
the vector magnitude that would have been calculated in absence of the respective category,
providing an indication of the extent to which individual categories or combinations of categories
drive the overall vector magnitude and overall ranking. Appendix C provides additional technical
detail as well as an applied example of vector analysis, including the type of analyses used to
derive Figure 3-3, Table 3-2, and similar figures and tables in subsequent sections of this report.
Where only one or two impact categories associated with a high-ranking input have relatively
strong influence on the overall vector magnitude (i.e., as indicated by dark orange shading), this
indicates a situation where the high ranking is driven by a limited range of impacts (e.g., ozone
depletion potential impacts associated with mineral wool). Where moderate influence on the
overall vector magnitude exists across several categories, this suggests a diverse range of life
cycle impacts associated with the input (e.g., ready-mixed concrete).
31
-------
Table 3-2
Top Ranted Direct Inputs to Single-Family Home Construction (Pre-Occupancy Phase)
Based on Input Contribution Analysis
Rank
1
2
3
4
5
6
7
8
9
10
BEA
Code
360200
361200
170100
362000
320400
690200
650301
200904
90002
590301
BEA Description
Brick and structural clay tile
Ready-mixed concrete
Carpets and rugs
Mineral wool
Miscellaneous plastics products,
n.e.c.
Retail trade, except eating and
drinking
Trucking and courier services,
except air
Reconstituted wood products
Sand and gravel
Motor vehicles and passenger car
bodies
Vector
Mag.
21.89
18.68
15.65
15.62
14.57
14.02
12.01
11.79
11.69
10.62
Factor Influence
(change in vector orientation introduced by factor in degrees)
Q.
Q
<
2
13
0
10
15
17
10
16
2
14
o
^
_i
0
3
9
4
9
9
37
13
-1
12
Q_
C3
2
25
0
11
13
16
15
16
2
16
Q_
Q
O
0
1
0
58
11
2
0
3
-1
5
i
25
5
1
8
19
9
2
7
0
16
Q_
i
0
2
48
6
14
7
2
5
-1
21
Q.
is
40
1
0
1
2
3
0
2
0
3
Q.
E
-1
2
39
8
18
9
3
6
-2
23
Q_
t;
E
40
1
0
1
3
3
0
2
0
4
Q.
ti
-1
4
2
13
31
10
2
10
-2
14
Q_
O
o
Q.
0
20
0
10
15
14
30
13
0
17
Q_
<
0
27
0
6
13
19
12
13
0
14
Q_
LJJ
0
26
8
7
15
13
23
12
0
16
o
LJJ
0
11
0
7
10
23
16
36
3
16
§
0
9
1
9
14
36
4
21
3
15
_i
i—
0
17
-1
0
0
1
0
2
46
0
1
1
17
0
5
9
7
4
18
43
7
Key: Cells are shaded using a gradient, where orange-shaded cells indicate that the impacts associated with the
material/product/service are above the mean for all materials/products/services and blue-shaded cells indicate that the
impacts associated with the material/product/service are below the mean. Darker shading indicates relatively stronger
influence of the impact category on the overall vector magnitude.
This more detailed review suggests that some direct inputs to single-family home construction are
ranked highly based on related impact categories. For example, the relatively high ranking
associated with brick and structural clay tile derives from its relatively high impact along three
potentially related dimensions: human toxicity potential (HTP), marine aquatic ecotoxicity
potential (MAETP), and freshwater sediment ecotoxicity potential (FSETP). This clustering of
impacts and drivers was further explored by conducting vector analyses on groups of impact
categories described in Section 2.3 and summarized below.
1. Natural Resources and Land Use - waste (WST), abiotic depletion potential (ADP), energy
consumption (EC), water consumption (WC), land use competition (LUC), and material input
(MTL);
2. Toxicity - human toxicity potential (HTP), freshwater aquatic ecotoxicity potential (FAETP),
marine aquatic ecotoxicity potential (MAETP), terrestrial ecotoxicity potential (TETP),
freshwater sediment ecotoxicity potential (FSETP), and marine sediment ecotoxicity potential
(MSETP); and
3. Pollution Impact - stratospheric ozone depletion potential (ODP), global warming potential
(GWP), acidification potential (AP), euthrophication potential (EP), and photochemical
ozone creation potential (POCP).
32
-------
Figure 3-4 summarizes the results of these analyses of factor groupings and highlights the nature
of the impact categories driving the rankings behind the top-ranked materials, products, and
services identified in Figure 3-3. For example, the analysis by groupings indicates that the high
ranking associated with sand and gravel is driven primarily by resource use; high ranking
associated with brick and structural clay tile is driven by toxicity impacts; and high rankings
associated with some materials and products, such as ready-mixed concrete, reconstituted wood
products, and miscellaneous plastics products are driven by a range of impact
types.47
Figure 3-4
Highest Ranked Materials, Products and Services Based on Different Scopes
Input Contribution Basis - Pre-Occupancy Stage
Scope: Natural Resource and Land Use
Sand and gravel
9
Ready-mixed concrete
Reconstrtuted wood products
Sawmills and planing mills,...
Asphalt paving mixtures and...
Trucking and courier services,...
Wholesale trade
Miscellaneous plastics products,...
^—
^^^m
^m
™
0 5 10
15
Vector Magnitude
Scope: Toxicity
Brick and structural clay tile
pe ug
Motor vehicles and passenger, . .
Cut stone and stone products
Converted paper products, n.e.c.
Paints and allied products
Mineral wool
Wholesale trade ^^^
Retail trade, except eating and ... ^^^H
•
1
1
0 5 10 15 20 25
Vector Magnitude
Ready-mixed concrete
Scope: Pollution
Trucking and courier services,. ..^^^^^H
^
Miscellaneous plastics products,. ..^^^^^^^^H
Retail trade, except eating and...^^^^l^MH
Cement, hydraulic
Motor vehicles and passenger... ^^^^^H
Reconstituted wood products
Wholesale trade
Millwork
^^H
•
1
0 5 10 15 20
Vector Magnitude
47 Through possible correlations in their supply-chains, inputs that are ranked highly within the same
groupings of environmental impacts could point to industry sectors within their supply-chains that contain
"hotspots" for those groups of impact categories. Those sectors could then be examined for the
appropriateness of a mitigation measure. For example, ready-mixed concrete and reconstituted wood
products are ranked as top 10 inputs for their high impacts in both Natural Resource and Land Use and
Pollution groupings. The supplemental contribution analyses, pages 38- 41, provide a glimpse into the
sectors within their supply-chains that cast the highest impacts. If mitigating impacts of ready-mixed
concrete and reconstituted wood products within Natural Resource and Land Use and Pollution groupings
were of high priority, targeting those sectors that are highlighted within Natural Resource and Land Use
and Pollution groupings that are in common for the two products could be effective. Since sector data are
33
-------
Summary - Input Contribution Analysis, Pre-Occupancv Phase
The input contribution analysis for the pre-occupancy phase suggests the following findings:
• Material use as a dominant factor - The relatively high ranking of certain construction
materials can be attributed to the influence of the material use factor, which measures
impact in terms of weight. This includes materials and products such as ready-mixed
concrete and sand and gravel. In the case of sand and grave I, this and the waste factor
(which is also weight-based) are the principal drivers of the high ranking. The relatively
high ranking of ready-mixed concrete reflects a more complex set of embodied impacts,
not just material use. The material use factor provides an indication of physical land
and/or ecosystem disturbance, distinct from pollution or toxics-based disturbance. By
highlighting sand, gravel, and similar materials, the material use factor appears to be
serving this function.
• Toxicitv factors as primary drivers - The relatively high ranking of some direct inputs
used in the pre-occupancy phase of a single-family home is driven by toxicity factors,
including human and ecological toxicity factors. Direct inputs falling into this category
include brick and structural clay tile. Section 3.4.5 reviews the potential sources of toxic
impacts associated with brick and structural clay tile.
• Diverse embodied impacts reflective of diverse products categories - Some product and
service categories encompass a diverse set of inputs used directly in single-family home
construction and embody a diverse set of upstream processes. The complexity of these
product/service categories and upstream processes is reflected in the results, where they
are ranked relatively highly based on moderate effects across diverse sets of impact
categories. Products and services that fit this profile include miscellaneous plastic
products, retail trade, trucking and courier services, and motor vehicles and passenger
car bodies.
• Narrowly defined products with diverse mix of impacts - In contrast to the diverse
products and service categories described above, some product categories are relatively
narrowly defined but, nonetheless, the analysis indicates impacts across diverse sets of
categories. This is reflective of a situation whereby the relatively high ranking is driven
by the complex ways in which a limited set of upstream processes impact the
environment. The ranking is a result of the complexity of the product-environment
interactions rather than the complexity of the product category. Products that fit this
profile include ready-mixed concrete and reconstituted wood products.
aggregated, sectors that are common for the two should be analyzed so that correct supply-chain products
and processes are identified for a mitigation measure.
34
-------
• Fiberglass and mineral wool - The product category mineral wool48 does not fit neatly
into any of the above categories. It is a narrowly defined product with a relatively high
ranking that is driven primarily by a single factor, stratospheric ozone depletion potential
(ODP). In terms of single-family home construction, mineral wool is associated with
fiberglass and mineral wool insulation.
Finally, Figure 3-5 shows the percentage of the total estimated life cycle impacts associated with
the top 10 ranked direct inputs used in the pre-occupancy phase of single-family homes.
Depending on the impact category, impacts associated with the top 10 inputs account for
anywhere from just below 2% to just above 16% of the total life cycle impact of single-family
homes. This suggests that for some impact categories, the overall life cycle impacts associated
with inputs used in this phase are distributed across an array of inputs. For example, the top 10
inputs account for less than 2% of the overall life cycle water consumption (WC) of single-family
homes. Reductions in the water consumption associated with any one of the top-ranked inputs
may have little effect on the overall life cycle impact.
However, for other impact categories, the overall life cycle impacts are embodied in a more
limited set of inputs. In these situations, opportunities exist for significantly reducing selected
impacts by focusing on a narrow set of inputs. Stratospheric ozone depletion potential and
material input are examples of this, where one or two of the top-ranked inputs account for a
significant percentage of the overall life cycle impact (e.g., mineral wool accounts for an
estimated 11% of the life cycle stratospheric ozone depletion impacts associated with single-
family homes).
48 The "mineral wool" product category (BEA commodity 362000) encompasses a range of products,
including fiberglass insulation, mineral wool insulation, and related fiberglass and mineral wool products
(e.g., insulating bats). See section 3.4.2 for additional discussion.
35
-------
Figure 3-5: Contribution of 10 Most Highly Ranked Direct Inputs to Life Cycle Impacts
Associated with Single-family Home Construction (Pre-occupancy Phase)
1 R%
c
n
a. i c.o/ri
" 1 4%
5"
j
O 8%
s
SCO/
T flO/
O 70/,
'~ nOA
V
°- <;
jjTjj
<5^ ^^^
* Y
•N j
ij/1 ^^
/ ^
<£
v5 •Q"^ O O
•^ xj5" <5" *
^V
/>v\
^ /t
<^
• Brick and structural clay tile
• Ready-mixed concrete
| • Carpets and rugs
II Miscellaneous plastics products,
• 1 Retail trade, except eating and
| | | | | drinking
• Trucking and courier services,
«i^-^'C^^<;^'C^<^'C^<^\<^^<^" ^ except air
'^c^'o'?'c>^c>^c^'<5^c^' <5^^^-<^X Reconstituted wood products
^o*" ^ xjy ,c?" f $$ J& •& *& Sand and gravel
^ . ^ . ^ x° Motor vehicles and passenger car
$ £ 4$ bodies
Impact Category
3.3.2 Occupancy Phase
The input contribution analysis of the occupancy phase of the life cycle of a single-family home
focused on:
• Impacts associated with energy and water consumed in the home, including indirect
impacts associated with the production and delivery of electricity and water to the home
by utilities;
• Impacts associated with GHG emissions and acidifying substance emissions generated by
fuel combustion (e.g., natural gas for heating) in the home; and
• Direct and indirect impacts associated with the 13 specific products and an "other
product" category included to capture materials replaced during the life span of the home.
For replacement materials, direct and indirect impacts were rolled up and expressed as embodied
impacts. As a result, a total of 17 direct inputs were considered in this analysis: 13 specific
products and one "other" product category representing replacement materials, electric services,
natural gas distribution, and petroleum refining. Given this relatively narrow scope, vector
analysis was not used for ranking the materials, products, and services, as several of the key
conditions necessary for efficient operation of this approach were not met (e.g., skewed
distribution of mean-centered impact estimates).
36
-------
Rather, a single-factor vector analysis was conducted for each impact category. Using this
approach, six direct inputs were identified where at least one impact estimate exceeded one
standard deviation above the mean impact value for all 17 materials, products, and services
analyzed. The results are summarized in Table 3-3.
Table 3-3: Top Ranked Direct Inputs to Single-Family Home Construction (Occupancy
Phase) Based on Input Contribution Analysis
BEA
Code
170100
362000
200200
540700
680100
680202
BEA Description
Carpeting
Insulation (glass fiber)
Siding (wood shingle)
Other
Electric services (utilities)
Natural gas distribution
Q_
Q
<
•
•
o
_l
•
•
C3
•
Q_
Q
0
•
•
Q.
1—
•
%
LL.
•
LLJ
<
•
1—
LLJ
1—
•
ID
C/3
LL.
LLJ
C/3
S
•
O
0
Q.
Q.
<
Q_
LU
O
LU
O
_l
1—
S
•
%
•
Summary - Input Contribution Analysis, Occupancy Phase
The input contribution analysis for the occupancy phase of single-family homes suggests the
following findings:
• Energy consumption and related impacts - As Figure 3.6 shows, energy consumption and
the impacts associated with electricity generation and delivery dominate the life cycle
impacts associated with the inputs into the occupancy phase of single-family homes.
Electric services represent more than half of the overall life cycle impact of single-family
homes for 8 of the 17 impact categories analyzed and represent the highest contributor to
occupancy-phase life cycle impacts for 11 of the impact categories.
• Replacement materials -In the case of highly ranked replacement materials—wood
shingle siding and glass fiber insulation—significant contributions to life cycle impacts
are associated with a single impact category.
Finally, Figure 3-6 shows the contribution of these six direct inputs to the life cycle impacts
associated with single-family homes. Depending on the impact category, these six inputs
contribute anywhere from 20% to 90% of the total life cycle impact of single-family homes. This
analysis suggests that opportunities exist for significantly reducing the overall life cycle impacts
of single-family homes by focusing on a narrow set of inputs into the occupancy phase. The most
significant reductions in life cycle impacts of single-family homes could be realized through
reductions in electricity consumption and/or impacts associated with upstream supply processes
associated with electricity generation and distribution. Improvements in these areas could result
in reduced impacts across multiple natural resource and land use, toxicity, and pollution impact
categories.
37
-------
Figure 3-6: Contribution of 6 Most Highly Ranked Direct Inputs to Life Cycle Impacts
Associated with Single-family Home Use (Occupancy Phase)
u
2. QD0/,
u
re
O Aft0/,
- 3D%
<•>
QJ n%
_
•
•^^^^^.o*.o<
s> * ^* <£* Q? of Q?
-------
methodology as other life cycle analyses described herein, interpretation of the results focused
primarily on the sets of impacts for which the direct input was identified as significant in the
context of the life cycle impacts of single-family homes. For example, the interpretation of results
of supplemental analysis of fiber glass and mineral wool focused on embodied stratospheric
ozone depletion potential (ODP) impacts. This approach was adopted to maintain the focus on the
life cycle of single-family homes.
The results of these supplemental supply chain analyses are presented below. Section 5 of this
report discusses the potential for avoided impacts for some of these materials, including brick and
structural clay tile, ready-mixed concrete, and reconstituted wood products, and closely related
upstream supply chain processes.
3.4.1 Fiberglass and Mineral Wool (Insulation)
Life cycle impacts associated with fiberglass and mineral wool insulation used in single-family
homes are captured in the BEA mineral wool product category.49 In newer homes, fiberglass and
mineral wool insulation is typically installed when the home is built (pre-occupancy phase). For
older homes, fiberglass and mineral wool insulation may be installed during the occupancy phase
of the home for weatherization and to improve energy efficiency. New residential construction,
renovation, and the manufacturing of products used in single-family homes (e.g., appliances)
accounted for more than half of the demand for products in the mineral wool category in 1998
(DOC 2010b). Once installed, fiberglass and mineral wool insulation typically last for the
lifespan of the home (see Table 1-3).
The pre-occupancy-phase input contribution analysis suggests that mineral wool contributes
significantly to the overall life cycle impacts associated with single-family homes primarily due
to stratospheric ozone depletion potential (ODP) impacts, though the analysis also suggests
contributions to other embodied impacts across all of the impact groupings (see Table 3-2). The
occupancy-phase input contribution analysis highlights the significant contribution of mineral
wool to the overall ODP life cycle impacts associated with single-family homes.
Figure 3-7 presents the results of the supplemental contribution analysis of fiberglass and mineral
wool used in the insulation of single-family homes. For the ODP impact category, nearly half of
the impacts are associated with the mineral wool product category itself, suggesting that direct
emissions of stratospheric ozone layer depleting substances during the manufacture of mineral
wool, rather than upstream supply chain processes, are the principal contributor to this impact.50
49 The "mineral wool" product category (BEA commodity 362000) encompasses a range of products,
including fiberglass insulation, mineral wool insulation, and related fiberglass and mineral wool products
(e.g., insulating bats). See, for example, NAICS category 327993, Mineral Wool Manufacturing
(http://www.census.gov/cgi-bin/sssd/naics/naicsrch?code=327993&search=2007%20NAICS%20Search),
which is the analog of BEA commodity.
50 Output contribution analysis disaggregates the impacts embodied in a material, product, or service to the
upstream supply chain processes where the emissions associated with the impacts occur. The portion of the
total embodied life cycle impact that is not disaggregated to upstream supply chain processes represents the
impacts associated with the production of the material, product, or service being analyzed.
39
-------
Figure 3-7: Supplemental Contribution Analysis of Fiberglass and Mineral Wool
(Insulation) Used in Single-family Homes
QfW _
50°/
n0/
o x^
/9
/ ^
*>O Q Q Q Q Q Q Q
j-Sto ^* icV »^\ x^v xrK «d^ >c?^
V1 -J& Jf" "V* •Jp" •*?* 'T *T 'i
** ^ o -O O O -O -O .v
^ o .0" ,o" ,o" ,o" ,<3" <>
<.b v^ a° fr ^ £ fr <§> „
**//////
^ j£ *& ^ J?
•" "^ ^ ^ o9
/
- .* ^
cT c?
KldbllLS FIldLeildlb dllU
resins
Miscellaneous crops
Nonmetallic mineral
miscellaneous
Trucking and courier
• Paper and paperboard
• Industrial inorganic and
^ organic chemicals
'
-------
suggests that direct emissions during the manufacture of ready-mixed concrete are a significant
source of impact in this grouping.
Sand and gravel was identified as the most important upstream supply chain process associated
with relatively significant material use and waste life cycle impacts embodied in the ready-mixed
concrete used to build single-family homes. Electric services also contribute significantly to
embodied impacts across multiple impact categories.
Figure 3-8: Supplemental Contribution Analysis of Ready-Mixed Concrete Used in Single-
family Homes
100%
90%
80%
70%
50%
40%
^-*
±
I
t
Gum and wood chemicals
Surface active agents
Crude petroleum and
natural gas
Trucking and courier
services, except air
Coal
Ready-mixed concrete
.
£
.
Cement, hydraulic
Electric services (utilities)
3.4.3 Wood Shingle Siding
Wood shingle siding was considered in the analysis of material replacement during the occupancy
phase of a single-family home based on information presented in the Harvard University (2009)
study on the home remodeling market and replacement data available in the Oregon DEQ (2010)
study. In addition, wood shingle siding is the most frequently replaced of the materials commonly
used in North America for siding in single-family homes (Athena Institute, 2002). The
occupancy-phase input contribution analysis suggested that wood shingle siding contributes to the
life cycle impacts associated with a single-family home primarily based on the land use
competition (LUC) factor.
Figure 3-9 presents the results of the supplemental contribution analysis of wood shingle siding
used in single-family homes. Forestry products and agricultural, forestry and fishery services
supply chain processes contribute most significantly to the LUC impacts embodied in wood
shingle siding, reflecting the geographic footprint of forests managed for wood production. Other
41
-------
supply chain processes contributing significantly to embodied impacts associated with wood
shingle siding include electric services and sawmills and planing mills.
Figure 3-9
Supplemental Contribution Analysis of Siding (Wood Shingle) Used in Single-family Homes
100% T
QflO/ _
fid0/
7 n°/
cnoi
50% -
AfW£ -
3flO/ _
"3IW
1 n°/
n°/£
^
5"
/J
-,O O
•v!^ ^ -^
O ^ N^
/° "V%
/
/ s
jjr <$
£
*.//
" <^ 0^
^//
?v/
&~ t
X Qj
$ £
**
^
|
•
•
1
'//^
O O Q
///
^/ j
v c?1
-^
A*5
/
$
'*
f
1
>*
'^
"/
i
1
>"
'/
1 1
V "^
. fjf , 1
$°
1
>*
.
-------
For the four pollution impacts categories for which reconstituted wood products contributes
significantly to the overall life cycle impact associated with single-family homes, electric services
was identified as consistently significant source of embodied impacts within the reconstituted
wood products supply chain. The analysis also suggests that direct emissions during the
manufacture of reconstituted wood products are a significant source of impacts within this
grouping.
Figure 3-10: Supplemental Contribution Analysis of Reconstituted Wood Products Used in
Single-family Homes
100%
on0/
Sn0/, -
7HQ£
An0/
^n%
/in0/
3/yu;
"?n°/
1 n0/.
n°/
N
•
f /////////////
.$ &.& .$ -^ £> £• & •$> £> .$ .$ .$ £
///////////////
4? ^jp
-------
in the human toxicity, marine aquatic ecotoxicity, freshwater sediment ecotoxicity potential
impact categories. Toxic impacts associated with brick and structural clay tile likely derive from
the release of naturally occurring in toxic compounds during mining and high heat production
processes.51
Figure 3-11: Supplemental Contribution Analysis of Brick and Structural Clay Tile Used in
Single-family Homes
100% -r
7 n°/
fin0/,
50%
An0/.
3fM£
"?n°/
m°/
n%
^
- c? 6-*
/ ^
•^ ^"
'W
<^ <& <^
^
• .3
$
U4
f $
-/
• %
$
) C
>0 3
^°s
*^
$
,
Z?" (^
>" & <
' */*
-------
a. Policy responses intended to reduce the life cycle impacts associated with these direct
inputs and direct inputs exhibiting similar supply chain impact patterns could be
effectively focused on the product categories themselves (i.e., rather than upstream
supply chain processes).
b. Policy responses associated with these and similar materials and products could also
focus effectively on those processes that directly consume these products. For
example, because single-family homes and other residential structures account for a
significant percentage of the demand for fiberglass and mineral wool insulation and
brick and structural clay tile, policy responses focused on residential housing (i.e.,
design, construction, renovation, C&D waste management) could be an effective
avenue for encouraging reductions in the impacts associated with these products.
2. Life cycle impacts attributable to energy intensive supply chain processes - Ready-mixed
concrete and reconstituted wood products also fall into the category above (life cycle impacts
attributable to direct inputs). In addition, the analyses of these products suggest that a
significant portion of their life cycle impacts in the single-family home context derive from
energy inputs, primarily electric services. This suggests that policy responses associated with
these and other products exhibiting similar supply chain impact patterns could be most
effective if conducted as integrated energy- and emissions- focused responses. SMM
concepts and strategies present a framework for such an integrated approach.
3. Wood products and forestry - Forestry and related forestry services processes account for
almost 40% of the life cycle land use competition impacts embodied in wood shingle siding
and almost 30% of the life cycle impacts embodied in reconstituted wood products.
Depending on how they are managed, forests can represent an important carbon sink. In the
United States, forests account for the majority of the carbon sequestration experienced over
the past two decades due primarily to a net increase in carbon accumulation in forest stocks
(EPA 2011). This illustrates the connectivity of the impacts included in this life cycle analysis
and the importance of weighing multiple factors when evaluating policy responses. For
example, efforts to reduce the land dedicated to forestry for single family homes could have
implications for the life cycle global warming potential impacts associated with single family
homes.52
4. Material Input and Waste -The supplemental analysis indicates that upstream supply chain
processes associated with sand and gravel contribute significantly to the material use and
waste life cycle impacts embodied in the ready-mixed concrete used to build single-family
homes. Similarly, the manufacturing of reconstituted wood products contributes significantly
to the waste life cycle impacts associated with this input to single-family homes. Policy
responses focused on feeding industrial waste back into the manufacturing and upstream
supply chain processes (e.g., the use of concrete from demolished buildings as aggregate in
ready-mixed concrete, the recycling of wood panels back into the reconstituted wood
products manufacturing process) as well as policy responses focused on residential housing
52 The implications in terms of the direction of global warming potential impact would depend on several
factors, including forest management practices, demand effects for forest products on the forest biomass,
waste generated in producing inputs from harvested wood and the management of that waste, etc.
45
-------
(i.e., design, construction, renovation, C&D waste management) could be effective avenues
for encouraging reductions in the impacts associated with these products.
46
-------
4. RESULTS: OUTPUT CONTRIBUTION ANALYSIS
4.1 OVERVIEW
The following section presents the results of the output contribution analyses of the national
housing stock of single-family homes. Whereas the input contribution analysis described in the
previous section focused on the relative contribution of direct inputs to the overall life cycle
impacts associated with a single-family home, the output contribution analysis disaggregates
these impacts to their original sources in the upstream supply chain of the product system
Whereas the supplemental contribution analyses in the previous section focused on the upstream
supply-chain processes for specific inputs, the output contribution analysis included here will
focus on the supply-chain processes necessary to construct and operate all single-family homes
built in 1998 across the nation.
Section 4.2 presents the results of the output contribution analysis for the pre-occupancy phase of
the single-family home, Section 4.3 presents the output contribution results for the occupancy
phase, and Section 4.4 summarizes the overall findings from the output contribution analysis.
Appendix G presents detailed results of the output contribution analysis.
4.2 PRE-OCCUPANCY PHASE
Figure 4-1 highlights the top ten most highly ranked supply chain processes used to provide and
deliver inputs into the pre-occupancy phase of single-family homes from an output contribution
perspective. The analysis indicates that when all factors are considered equally (no weighting or
grouping), a relatively diverse mix of supply chain processes contributes to the overall life cycle
impacts of single-family homes. The analysis highlights energy services and related supply chain
process (e.g., electric services, coal), raw material extraction/production processes (e.g., sand and
gravel, dimension, crushed and broken stone), and transportation (i.e., trucking and courier
services').
47
-------
Figure 4-1: Highest Ranted Materials, Products, and Services, Full Scope (all impact
categories), Output Contribution Basis - Pre-Occupancy Phase
Electric services (utilities)
Cotton
Brick and structural clay tile
Trucking and courier services, except...
Sand and gravel
Crude petroleum and natural gas
Mineral wool
Coal
Industrial inorganic and organic...
Dimension, crushed and broken stone
0 10 20
Vector Magnitude
30
40
50
In addition, comparing these results to the results of the input contribution analysis (see Figure
3-3) highlights the differences in these two perspectives. Whereas the input contribution analysis
emphasized the contribution of more finished products to the overall life cycle impacts of home
construction, the output contribution analysis highlights the energy- and materials-related supply
chain processes contributing most significantly to the impacts embodied in the more direct
construction inputs. The two perspectives emphasize some of the same materials and products
and services. This is the case for:
• Materials and products where the supply chain from extraction to direct input to home
construction is relatively direct (e.g., sand and gravel);
• Products where the locus of impact is concentrated at the manufacturing stage of the
material/product (e.g, mineral wool, brick and structural clay tile); and
• Services that are ubiquitous throughout the supply chain (e.g., transportation and courier
services).
Table 4-1 further explores these results by analyzing the impact categories behind the relatively
high rankings developed using the vector analysis approach. The table lists the 10 most highly
ranked supply chain processes contributing to the life cycle impacts associated with single-
family-home pre-occupancy phase, considering all of the impact categories. As with Table 3-2,
the values associated with each impact category in the table provide an indication of the extent to
which individual categories or combinations of categories drive the overall vector magnitude and
overall ranking.
Where only one or two impact categories associated with a high-ranking input have relatively
strong influence on the overall vector magnitude (i.e., as indicated by dark orange shading), this
indicates of a situation where the high ranking is driven by a limited range of impacts (e.g., the
abiotic depletion impacts associated with crude petroleum and natural gas). Where influence on
48
-------
the overall vector magnitude exists across several categories, this suggests a diverse range of life
cycle impacts associated with the input (e.g., electric services').
Table 4-1: Top Ranted Supply Chain Processes Associated with Single-family Home
Construction (Pre-Occupancy Phase), Based on Output Contribution Analysis
Rank
1
2
3
4
5
6
7
8
9
10
BEA
Code
680100
20100
360200
650301
90002
80001
362000
70000
270100
90001
BEA Description
Electric services (utilities)
Cotton
Brick and structural clay tile
Trucking and courier services, except air
Sand and gravel
Crude petroleum and natural gas
Mineral wool
Coal
Industrial inorganic and organic
chemicals
Dimension, crushed and broken stone
Vector
Mag.
45.35
28.97
28.30
20.11
18.66
18.10
17.46
16.97
16.40
13.66
Factor Influence
(change in vector orientation introduced by factor in degrees)
Q.
Q
<
0
0
0
0
0
71
0
47
0
0
o
^
_i
0
9
0
41
0
0
0
0
0
-1
Q_
C3
22
0
1
11
1
9
4
3
3
2
Q.
Q
O
0
0
0
0
0
0
81
0
38
-1
i
8
0
21
0
0
0
3
2
23
-1
Q_
i
0
45
0
0
0
0
0
1
4
0
Q.
Is
<
11
0
41
0
0
0
0
1
1
0
i
0
42
0
0
0
0
1
1
9
-1
Q_
Is
E
11
0
41
0
0
0
0
1
3
0
£
»
0
0
0
-1
-1
0
5
-1
38
-1
Q_
O
o
Q.
17
0
0
35
0
7
5
1
7
0
Q_
<
26
0
0
5
0
3
0
0
4
0
Q_
LJJ
18
10
0
24
0
5
1
-1
6
0
o
LJJ
25
0
0
10
2
1
1
0
0
2
§
28
0
0
0
0
0
0
0
0
0
_i
0
0
0
0
59
1
0
3
1
87
1
0
0
0
0
31
14
0
42
9
0
Key: Cells are shaded using a gradient, where orange-shaded cells indicate that the impacts associated with the
material/product/service are above the mean for all materials/products/services and blue-shaded cells indicate that the
impacts associated with the material/product/service are below the mean. Darker shading indicates relatively stronger
influence of the impact category on the overall vector magnitude.
For most of the supply chain processes highlighted in the output contribution analysis, the
relatively high rankings are based on related impact categories. Referring to the impact groupings
described in Section 2.3:
1. Supply chain processes associated with sand and gravel, crude petroleum and natural gas,
coal, and dimension, crushed and broken stone are ranked highly based on the impact
categories in the natural resources and land use grouping;
2. Supply chain processes associated with brick and structural clay tile are ranked highly based
on the impact categories in the toxicitv grouping; and
3. Other supply chain processes are ranked relatively highly based on a more diverse mix of
impacts that cut across groupings, including those associated electric services and trucking
and courier services (pollution impacts and natural resources and land use) and those
associated with industrial organic and inorganic chemicals (toxicitv and pollution impacts).
A more complete summary of the output contribution vector analysis is presented in Appendix G.
Figure 4-2 shows the percentage of the total estimated life cycle impacts of single-family homes
represented by the top 10 ranked pre-occupancy supply chain processes. Depending on the impact
category, impacts associated with the top 10 supply chain processes account for anywhere from
just above 3% to almost 60% of the total life cycle impacts of single-family homes. This finding
also highlights the relative differences in perspectives offered by input and output contribution
49
-------
analysis, with implications for how these different analyses can inform SMM policy decision
processes.
Figure 4-2: Contribution of 10 Most Highly Ranked Supply Chain Processes to Life Cycle
Impacts Associated with Single-family Home Construction (Pre-occupancy Phase)
u
n
a.
- fift0/,
~
41
S3f»0/
|
_g ZU/o -
4-1
c
3
" n% -
1 III!
ii. Mill i,i.,
• Electric services (utilities)
• Cotton
• Brick and structural clay tile
• Trucking and courier services,
• Sand and gravel
except air
Crude petroleum and natural gas
°" .^ o .£• -£• .^ .£• .^ -^ ^ • £• ^ -£* -%• c^ *£^ 'C** «d^ C1 ^ ^ ^^ ^ "^
i$? i<> -^j -^ -^ -X" -X? -Xj1 i(^ x> O O
-------
4.3 OCCUPANCY PHASE
Figure 4-3 highlights the top ten most highly ranked supply chain processes used to provide and
deliver inputs into the occupancy phase of single-family homes from an output contribution
perspective. As noted in Section 3.3.2, the occupancy phase of the life cycle of a single-family
home focused on energy and water consumption and replacement materials. The output
contribution analysis distributes the impacts associated with these direct inputs to associated
upstream supply chain processes.
Figure 4-3
Highest Ranked Materials, Products, and Services
Full Scope (all impact categories)
Output Contribution Basis - Occupancy Phase
hlGctnc services {utilities)
Cotton
Coal ^^^^^^
Crude petroleum and natural gas ^^^^^^H
Mineral wool
Industrial inorganic and organic...
Paper and paperboard mills
Natural gas distribution
Plastics materials and resins
Agricultural, forestry, and fishery...
—
^
—
0 20 40 60 80
Vector Magnitude
The analysis reflects the make-up of the inputs used to analyze the occupancy phase of single-
family homes. It highlights the contributions to the overall life cycle impact of upstream supply
chain processes associated with replacement materials, agriculture, forestry, and fishery services,
paper and paperboardmills, and plastics materials and resins as inputs to wood products.53 Like
the pre-occupancy phase analysis, the occupancy phase output contribution analysis identifies
fiberglass and mineral wool insulation as a significant contributor to life cycle impacts because:
1) it was included in the scope of replacement materials and 2) the locus of impact is concentrated
at the manufacturing stage of the product (see Section 3.4.2).
The analysis differs from the output contribution analysis for the pre-occupancy phase in that it
does not highlight materials associated with new building construction (e.g., brick and structural
clay tile, sand and gravel, and dimension, crushed and broken stone). This in part reflects the
definition of the scope of replacement materials and in part reflects the fact that these materials
are less important in the supply chain associated with the occupancy phase of single-family
53 Products in the plastics materials and resins category are an important input to the manufacturing of
reconstituted wood products (DOE 201 Ob).
51
-------
homes. The two analyses are similar in that they highlight the importance of energy services and
related materials throughout the life cycle of single-family homes.
Table 4-2: Top Ranted Supply Chain Processes Associated with Single-family Home
Construction (Occupancy Phase), Based on Output Contribution Analysis
Rank
1
2
3
4
5
6
7
8
9
10
BEA
Code
680100
20100
7000
80001
362000
270100
240800
680202
280100
40001
BEA Description
Electric services (utilities)
Cotton
Coal
Crude petroleum and natural gas
Mineral wool
Industrial inorganic and organic chemicals
Paper and paperboard mills
Natural gas distribution
Plastics materials and resins
Agricultural, forestry, and fishery services
Factor Influence (change in vector orientation, in degrees)
Vector
Mag.
63.23
30.91
29.42
17.05
16.38
15.16
10.14
9.40
8.98
8.12
S
<
0
0
30
64
0
0
0
0
0
0
o
^
_i
0
18
0
0
-1
-1
-1
-1
Q_
1
19
0
1
5
0
0
0
0
-1 0
79 1 0
Q.
Q
O
0
0
0
0
84
37
0
-1
18
-1
Q_
19
0
2
0
1
7
7
0
9
-1
Q_
Is
2
1
43
2
0
0
2
2
0
3
8
1
20
0
1
0
0
0
0
0
0
0
i
2
42
3
0
0
5
6
0
7
7
Q_
Is
E
20
0
1
0
0
0
0
0
1
0
£
(/}
0
1
0
1
6
51
80
2
68
-1
Q_
O
s.
19
0
1
5
1
1
1
0
1
0
Q_
<
20
0
0
1
0
0
0
0
0
0
Q.
LJJ
19
2
0
3
0
1
0
0
0
1
o
LJJ
20
0
0
0
0
0
1
0
0
0
o
20
0
0
0
0
0
0
0
_i
0
0
37
15
0
2
~1>8
i—
0
0
38
19
0
2
0
mill
o| -i| -1
Key: Cells are shaded using a gradient, where orange-shaded cells indicate that the impacts associated with the
material/product/service are above the mean for all materials/products/services and blue-shaded cells indicate that the
impacts associated with the material/product/service are below the mean. Darker shading indicates relatively stronger
influence of the impact category on the overall vector magnitude.
The analysis of the impact categories behind the highly ranked supply chain processes of the
home occupancy phase highlights the following:
• Energy-related inputs (e.g., electric services, coal, and crude petroleum and natural gas),
and forestry services contribute most significantly to the natural resource and land use
life cycle impacts, reflecting the scope of energy inputs and replacement materials used
during the occupancy phase;
• Electric services, chemicals, and pulp and paper mills contribute most significantly to the
toxicity-related impacts; and
• Electric services and fiberglass and mineral wool insulation contribute most significantly
to pollution life cycle impacts.
Detailed results are presented in Appendix G.
Figure 4-4 shows the percentage of the overall life cycle impacts of single-family homes
attributable to the top 10 ranked supply chain processes needed for single-family homes'
maintenance and operation. Depending on the impact category, impacts associated with the top
10 supply chain processes account for anywhere from about 15% to almost 95% of the total life
cycle impact of single-family homes.
52
-------
Figure 4-4
Contribution of 10 Most Highly Ranked Supply Chain Processes to Life Cycle
Impacts Associated with Single-family Home Construction (Occupancy Phase)
100%
u
n
fi. 90%
5
o) 70%
To 60%
s
g 40% --
V
| 30% -•
§ 10%
<*• 0%
1
1
* *?
• Electric services futilities)
• Cotton
• Coal
• Paper and paperdoard mills
Q ri< QQQQQQ'Q'QQ^'Q c^ t-> ^
&!*'&•>$&&
-------
indicates that those direct inputs contribute significantly to the life cycle impacts
associated with single-family homes through predominantly their manufacturing
processes. Materials/products that fall into this category include brick and structural clay
tile (pre-occupancy phase) and mineral wool (pre-occupancy and occupancy phases)
Ecotoxicitv factors as primary drivers -A relatively few highly ranked supply chain
processes contribute significantly to life cycle ecotoxicity impacts. These include supply
chain processes associated with electric services, brick and structural clay tile, paper and
paper board mi Us, pulp mills, industrial organic and inorganic chemicals, and plastics
materials and resins.
Construction materials - Construction materials, including sand and gravel and
dimension, crushed and broken stone contribute significantly to the material inputs
consumed in the life cycle of single-family homes, either directly during construction or
indirectly as building blocks for other materials (e.g., concrete). The supply-chain
processes of construction materials were highlighted for their contribution to the overall
life cycle impacts of single-family homes mainly through the pre-occupancy output
analysis. This is understandable being that over the home life cycle, construction
materials are predominantly used during initial construction, i.e., pre-occupancy phase.
Transportation - The importance of transportation services in terms of the life cycle
impacts associated with single-family homes is highlighted by the relatively high ranking
in the output contribution analysis. Fuel combustion related to transportation services
contributes significantly to the life cycle energy consumption and air emissions-related
impacts associated with single-family homes. Transportation services also represent
significant contributions to life cycle land use and eutrophication potential impacts, most
likely due to impacts associated with surface transportation systems.
54
-------
5. AVOIDED IMPACTS ANALYSIS
5.1 OVERVIEW
The input and output contribution analyses, relative ranking, and supplemental contribution
analyses, indicated that a diverse mix of inputs and that energy (in the form of direct and indirect
electricity consumption and direct consumption of fossil fuels) contribute significantly to the life
cycle impacts associated with single-family homes. Based on the findings from these analyses,
the following environmental mitigation scenarios were tested to analyze the potential for avoided
impacts through reduced material and resource use:
• Improving end-use efficiency of electricity
• Improving end-use efficiency of natural gas
• Increasing reuse of major input materials, where the brick and structural clay tile product
category was used to explore this scenario
• Increasing recycling of major input materials, where the product categories ready-mixed
concrete, carpets and rugs, and reconstituted wood products were used to explore this
scenario
In addition to their significance to the life cycle impacts associated with single-family homes,
these scenarios were selected to illustrate SMM concepts using options that are technologically
feasible and are familiar to a broad range of readers. The approach for analyzing potential
avoided environmental impacts associated with these scenarios and the results of the analysis are
described below.
5.2 METHODOLOGY FOR ANALYSIS OF POTENTIAL FOR AVOIDED
IMPACTS
5.2.1 End-Use Energy Efficiency
The first two scenarios considered the effects of energy efficiency improvements associated with
five residential electrical end use categories—space heating, space cooling, water heating,
refrigeration, and lighting—and two natural gas end use categories—space heating and water
heating. Estimates of potential energy efficiency improvement potentials were derived from the
Energy Information Agency's (EIA) Annual Energy Outlook (AEO) 2011 (DOE 201 Ib) and
assumptions based on other sources.
Table 5-1 shows the total electricity purchased by households in 2008 for the five end use
categories considered in the analysis, share of the electricity delivered that is represented by these
end uses, and potential efficiency improvements incorporated into the analysis. The end use
categories included in the analysis represent 59% of the total electricity delivered.
55
-------
Table 5-1
Electricity Efficiency Improvement Potential by End Use Categories
Space Heating
Space Cooling
Water Heating
Refrigeration
Lighting
Sum
Purchased
Electricity, 2008
(quadrillion Btu)1
0.28
0.87
0.43
0.37
0.72
2.68
Share in the total
electricity
delivered
6%
22%
9%
7%
14%
59%
Efficiency
improvement potential
(2008-2030)2
14%
19%
12%
28%
50%3
27%
Source
EIA, 2011
EIA, 2011
EIA, 2011
EIA, 2011
Assumption
1 DOE 2011b,Table A4, p. 124
2 Derived from the reference case for the Residential Sector Equipment Stock and Efficiency scenario,
DOE 20lib (electronic dataset)
3 An efficiency scenario for lighting was not available from the Residential Sector Equipment Stock and
Efficiency scenario. The Energy Independence and Security Act 2007, specifies that general purpose light
bulbs should be at least 30% more efficient by 2014 than then-current incandescent light bulbs. There are a
few states that mandate phase-out of incandescent light bulbs. LEDs consume about 10% of the energy
used by equivalent incandescent light bulbs. Given the pace of efficiency improvement, 50% of efficiency
gain by 2030 was considered to be reasonable.
Table 5-2 shows the total amount of natural gas purchased by households in 2008 for the two end
use categories considered in the analysis, share of the natural gas delivered that is represented by
these end uses, and potential efficiency improvements incorporated into the analysis.
Table 5-2
Natural Gas Efficiency Improvement Potential by End Use Categories
Space Heating
Water Heating
Sum
Purchased NG,
2008 (quadrillion
Btu)1
3.40
1.33
4.73
Share in the
total NG
delivered
67%
27%
95%
Efficiency
improvement potential
(2008-2030)
6%
12%
8%
Source
EIA, 2011
EIA, 2011
1 DOE 2011b,Table A4, p. 124
Using these estimates, the avoided environmental impacts associated with improvements in
electricity and natural gas end use efficiency were estimated considering both indirect impact
(supply-chain impact) and direct impact (combustion emissions and direct resource use).
Note that DOE (201 Ib) forecasts reductions in per capita household energy use due to efficiency
gains in space heating, water heating, and lighting equipment and population shifts to warmer and
drier climates. However, DOE forecasts that overall energy consumption by residential homes
will rise due more-than-offsetting growth in population, the number of homes, and the average
square footage of homes. Therefore, the potential reductions associated with energy efficiency
improvements estimated herein are an indication of the magnitude of the environmental impact
56
-------
reduction that could be attained with energy efficiency improvements relative to the DOE
forecast. They do not represent an estimate of absolute reduction in energy consumption.
5.2.2 Material Reuse and Recycling
Carpets and rugs and three of the five direct inputs with supplemental supply chain analyses
described in Section 2.4, were analyzed based on reuse and recycling potential: ready-mixed
concrete, brick and structural clay tile, and reconstituted wood products. Thefiberglass and
mineral wool insulation product category was not included, as little information was available
suggesting that the reuse or recycling of this material on a large scale has been considered. The
findings associated with the reconstituted wood products recycling scenario are illustrative of the
types and relative magnitude of impacts that could be avoided by comparable recycling of wood
shingle siding.
Table 5-3 lists the materials/products considered in the analysis of the potential for avoided
impacts, specific reuse/recycling scenarios, and assumptions regarding increased reuse and
recycling rates. The bases for these scenarios and assumptions are described below.
Table 5-3
Material Recycling/Efficiency Improvement Potential for Selected Direct Inputs
Product Category
Ready-mixed
concrete
Carpets and Rugs
Brick and
structural clay tile
Reconstituted
wood products
Reuse/recycling scenario
Ready-mixed concrete from demolished/
deconstructed single-family homes processed
and used as aggregate for roadway
construction.
Carpets and rugs removed from single-
family homes as a result of renovation and/or
demolition/deconstruction processed and
used as resin for manufacturing of various
synthetic products.
Brick from demolished/deconstructed single-
family homes reused in new construction
Reconstituted wood products from
demolished/ deconstructed single-family
homes burned as fuel for power generation in
paper and wood products industry
Increased reuse or recycling rate
20% increase in recycling of ready -mixed
concrete from current levels, resulting in
1% reduction in sand and gravel used as
aggregate for roadway construction
5% increase in recycling of carpets and
rugs from current levels, resulting in a
0.65% reduction in resin from other
sources used to manufacture various
synthetic products
15% increase in reuse of old brick in new
buildings relative to current levels
Wood recovery rates increased to a level
equivalent to replacing 5% of coal
currently consumed by wood and paper
products industry
The scenarios described in Table 5-3 were developed based on the following considerations:
• Ready-mixed concrete - Avoided environmental impacts associated with increased
recycling of concrete waste from single-family homes was calculated as follows:
o Scenario: At the end of its life, ready-mixed concrete is often crushed and used in
place of aggregate in the base course for road construction. This recycling scenario
was assumed for the purpose of this analysis.
o Recycling rate: In 2002, approximately 370 million tons of concrete waste from
building projects was generated in the United States (Cochran and Townsend, 2010).
By comparison, the United States consumed an estimated 1.13 billion metric tons of
57
-------
construction sand and gravel and 1.51 billion metric tons of crushed stone (USGS,
2003a; USGS, 2003b) in 2002. Approximately 65% of that concrete waste generated
in 2002 was recycled, which represents only 4% of the aggregate demand for 2002.
Given this potential demand, it was assumed that a 20% increase in the recycling rate
(to 85%) would be plausible.
o Material replacement rate: If the amount of concrete recycled increased to 85%,
recycled concrete from buildings would represent about 5% of the aggregate demand,
or an increase of 1%.
o Recycling vs. landfilling process substitution: The process for recycling concrete
involves crushing, sizing and transportation. Some research suggests that the
transportation load and environmental impact is reduced by recycling rather than
landfilling (USAGE, 2004). There is no clear evidence that recycling processes
require more energy and generate greater environmental impact relative to
landfilling. Therefore, the impacts associated with recycling were assumed to be the
same as those associated with landfilling the same amount of waste concrete.
o Overall net change: Based on an assumption of no net change in impact associated
with recycling versus landfilling, the overall reduction in impact was calculated as
the reduced impact associated with a 1% reduction in use of sand and gravel in
roadways.
Carpets and rugs - Avoided environmental impacts associated with increased recycling
of carpets and rugs salvaged from single-family homes was calculated as follows:
o Scenario: For the purposes of this analysis, it was assumed that resins derived from
processing salvaged carpets and rugs would be used to replace resins made from
virgin materials. Actual recycling pathways for carpets and rugs are more diverse
(CARE, 2010).
o Recycling rate: The U.S. Green Building Council's (USGBC's) proposed LEED for
Homes 2012 certification program provides an incentive for replacing 25% of needed
construction materials with salvaged materials. If the USGBC is able to change the
housing market such that 30% of new housing construction meets this standard,
approximately 7.5% of materials used for housing construction will be of
environmentally preferable source (including salvaged materials or recycled content
materials). In the absence of more detailed research, this was used as the basis for
assuming a 5% increase in the demand for salvaged carpets and rugs (comparable to
a 5% increase in recycling rate) between now and 2030.
o Replaced materials: Lave et al (1998) estimate that nylon carpet recycling can reach a
16.9% yield rate (i.e., 16.9 pounds of nylon can be produced from 100 pounds of
salvaged carpet). In the absence of more detailed research, it was assumed that
similar yield rates could be achieved for other types of carpets and rugs. In 2002, the
plastic materials and resins product category was a $45.4 billion business and the
carpets and rugs product category was a $ 11.7 billion business. Assuming that nylon
and carpets are priced on the same per unit mass, recycling all of the carpet produced
in 2002 as resin would replace 4.4% of resin [(11.7/45.4)*16.9%]. A 5% increase in
the carpets and rugs recycling rate would replace 0.22% of the resin produced. For
the purpose of this analysis, a factor of 3 was used to account for technological
improvements in the yield ratio between now and 2030, and the analysis assumed a
replacement rate of 0.65%.
58
-------
o Recycling vs. landfilling process substitution: Available literature and data regarding
the energy consumed and environmental impacts associated with producing resin
from salvaged carpets and rugs are limited. For the purposes of this analysis, it was
assumed that the amount of energy needed and impacts associated with recycling
would be similar to those associated with landfilling. No difference in transportation
was assumed.
o Overall net change: Based on an assumption of no net change in impact associated
with recycling versus landfilling, the overall reduction in impact was calculated as
the reduced impact associated with replacing 0.65% of resin made from virgin
material with resin made from salvaged carpets and rugs.
Brick and structural clay tile - Avoided environmental impacts associated with increased
recycling of brick salvaged from single-family homes was calculated as follows:
o Scenario: For this product category, a reuse scenario was analyzed. It was assumed
that brick salvaged from single-family homes would be used to replace brick made
from virgin materials.
o Recycling rate: The market for used brick for reuse in new construction has been
steadily rising while the market for new brick has been declining. This reflects in part
shifts in the availability of alternatives to new brick and changes in construction
techniques and styles. In 2002, the United States consumed approximately 15 million
tons of brick (BIA, 2006). That same year, the country generated approximately 17
million tons of brick as waste (Cochran and Townsend, 2010). If 5% of that is
currently reused as new bricks, it would represent approximately 5% of the brick
consumption. If demand for brick continues to stagnate and demand for used brick
continues to increase, reused brick could represent 20% of brick consumption, an
increase of 15%. This increased reuse rate of 15% was assumed for the purpose of
this analysis.
o Replaced materials: For this product category, a reuse scenario was analyzed.
Therefore, used brick would replace new brick on a one-to-one basis.
o Recycling vs. landfilling process substitution: For the purposes of this analysis, it was
assumed that the amount of energy needed and impacts associated with recycling
would be similar to those associated with landfilling. No difference in transportation
was assumed.
o Overall net change: Based on an assumption of no net change in impact associated
with recycling versus landfilling, the overall reduction in impact was calculated as
the reduced impact associated with replacing 15% of brick made from virgin material
with salvaged bricks.
Reconstituted wood products - Avoided environmental impacts associated with increased
recycling of reconstituted wood products salvaged from single-family homes was
calculated as follows:
o Scenario: Reconstituted wood products (e.g., wood panels) can be salvaged and
burned as fuel. For the purposes of this analysis, it was assumed that salvaged
reconstituted wood products would be used to replace coal combusted by the paper
and wood products industries to produce energy for manufacturing.
59
-------
o Recycling rate: In 2002, the wood products and paper products industries (NAICS
codes 321 and 322, respectively) consumed approximately 11.5 million tons of coal
to produce 237 trillion Btu of energy (DOE, 2006). Assuming a heating value of
7,400 Btu/lb for C&D wood waste (Jambeck et al., 2007), replacement of 5% of coal
consumption would require approximately 0.7 million mtons. McKeever (2004)
estimates that 25.2 million mtons of demolition waste wood was generated in 2002.
Based on these estimates, a 3% increase in recycling of C&D wood waste would be
required to replace 5% of the coal consumed by the wood and paper products
industries.
o Replaced materials: An increase in the recycling reconstituted wood products in an
amount equal to 3% of C&D wood waste (0.72 million nitons/year), would replace
approximately 5% of the coal used for energy generation by the wood and paper
products industries.
o Recycling vs. landfilling process substitution: For the purposes of this analysis, it was
assumed that the amount of energy needed and impacts associated with recycling
C&D wood waste would be similar to those associated with landfilling. No difference
in transportation was assumed.
o Overall net change: Based on an assumption of no net change in impact associated
with recycling versus landfilling, the overall reduction in impact was calculated as
the reduced impact associated with replacing 5% of the coal consumed by the wood
and paper products industries by reconstituted wood products salvaged from single-
family home demolition.
5.3 RESULTS
Figure 5-1 presents the results of the avoided impacts analysis aggregated by type of scenario—
i.e., end-use electricity efficiency, end-use natural gas efficiency, and material recycling rate/use
efficiency improvements. Figures 5-2 and 5-3 present the results for the different types of
scenarios. In terms of energy efficiency improvements, percentages used to express avoided
impacts can be interpreted in a straightforward manner—they represent reductions in life cycle
impacts associated with more efficient energy use during the occupancy phase of the single-
family home life cycle.
In terms of material reuse and recycling scenarios, the results can be interpreted in terms of
offsets to life cycle impacts associated with single-family homes. For example, the reductions in
material input impacts associated with substituting salvaged concrete for sand and gravel in
roadways do not reduce the actual life cycle impacts associated with the universe of homes
considered in this analysis. Rather, the recycling of concrete as road base material reduces
material inputs required by the roadway construction sector. These reductions in material input
are then used to offset the life cycle impacts associated with the single family homes from which
the concrete was salvaged. Percentages in the following figures can be interpreted as the
percentage of the original life cycle impacts of single-family homes offset by reuse and recycling
of salvaged materials.
60
-------
Figure 5-1: Potential Avoided Impacts Associated with Energy Efficiency
Improvements and Material Reuse/Recycling Scenarios (Composite View)
1
n
|
1
~ 20% --
c
0)
u
30%
O" v^
I
•» * -s
j8a ^* <5
\ x
*JTA
<3~ n"
^.
5" <5
^ c
rt-
&
»
^ <,
. ^
^
^
* <5
^^
a
^
i
3"° <,
^s-
/£/'f/'//'&ff/f*
//'ys/
61
-------
Figure 5-3: Potential Avoided Impacts Associated with Material Reuse/Recycling
Scenarios Considered for Single-family Homes
no/
2% -
i
•TO
O J^Q/o _
Jg 5%
Q.
u
(J
S 12%
V
a. i /jo/
16%
'/
»
j-
\
<
ii
1
^ fv X v
• O" & •$
^ ^ <£~
o o o
^ V '
- £• •!
<& <£
y/t
i
- .-*• .^
<^ <&
'•& ^
^ n?^ n
1
- •*• •*
£• £
/^
...
1
• Reconstituted wood
products
• Brick
• Carpets and Rugs
• Ready-mixed concrete
«? ^ of
-------
o The contribution of the different scenarios to avoided impacts in other categories—
abiotic depletion potential, human toxicity potential, material input, and waste —is
fairly balanced.
The analysis again highlights an important quality of multi-criteria LCA, previously
discussed in Section 3.4.1 of this report. Specifically, the analysis indicates that though
the energy efficiency and material reuse/recycling scenarios account for a relatively small
reduction in material input (6%), reduced impacts associated with these scenarios could
be substantially greater (up to 28%). This highlights the finding that impacts may not
correlate with measures of material input and that some materials may have an inordinate
effect on an impact category, pound-for-pound.
Electricity efficiency improvements: The analysis indicates that overall, improving
efficiencies in lighting, space heating, space cooling and water heating could result in
reductions of 12-27% in the life cycle impacts associated with single-family homes
across the following range of impact categories: abiotic depletion potential, global
warming potential, human toxicity potential, marine aquatic ecotoxicity potential,
freshwater sediment ecotoxicity potential, photochemical ozone creation potential,
acidification potential, eutrophication potential, water consumption, and waste. The
analysis suggests that the most significant contributions to avoided impacts would result
from the efficiency improvements in natural gas water and space heating, lighting, and
electric space cooling.
Material reuse and recycling scenarios: The analysis indicates that the improvements in
material reuse and recycling rates considered herein could result in reductions of 6-14%
in life cycle impacts associated with single-family homes in the following impact
categories: abiotic depletion potential, stratospheric ozone layer depletion potential,
human toxicity potential, freshwater aquatic ecotoxicity potential, terrestrial ecotoxicity
potential, marine sediment ecotoxicity potential, and waste. The analysis suggests that
meaningful reductions could also be achieved in other life cycle toxic impacts,
eutrophication potential, material input and waste.
In terms of the relative importance of material reuse and recycling scenarios to these
avoided impacts the analysis suggests the following:
o For all but three of the impact categories, avoided impacts associated with recycling
carpets and rugs into resin for various synthetic materials accounts for most of the
potential avoided impacts. The exceptions are abiotic depletion potential, material
input, and waste. Recycling of carpets and rugs account for 9-13% reductions in life
cycle impacts associated with single family homes across the stratospheric ozone
depletion potential, freshwater aquatic ecotoxicity potential, terrestrial ecotoxicity
potential, and marine sediment ecotoxicity potential impacts categories.
o The analysis suggests that the increased recycling of salvaged reconstituted wood
products as an energy source for the wood and paper products industries could offset
63
-------
7% of the life cycle abiotic depletion potential and 5% of the life cycle waste impacts
associated with single family homes.
o The analysis indicates that the scenarios analyzed for concrete recycling and brick
reuse would have little effect on the overall life cycle impacts associated with single-
family homes.
• For concrete, this is likely because even significant increases in concrete
recycling could replace only a relatively small percentage of aggregate and also,
because impacts associated with aggregate materials are of relatively limited
scope (primarily material input and waste).
• For brick, while the absolute reductions in life cycle impacts could be significant,
the relative reduction in life cycle impacts associated with a 15% increase in
reuse rates would translate to a 1% reduction in categories where brick and
structural clay tile contribute significantly to the life cycle impacts of single
family homes—human toxicity potential, marine aquatic ecotoxicity potential
(MAETP), and freshwater sediment ecotoxicity potential. For example, the life
cycle MAETP impacts associated with single family homes, though this product
category still only accounts for 7.5% of the total MAETP impacts. While a 15%
increase in reuse decreases the MAETP impacts associated with brick and
structural clay tile by 15%, this translates into a 1.1% reduction in total life cycle
MAETP impacts associated with single family homes (7.5% of total * 15%
reduction).
5.4 EXTENDED SUSTAINABILITY BENEFITS - ENVIRONMENTAL
JUSTICE AND EQUITY
Environmental Justice and Equity54
The two avoided impact scenarios discussed above quantify the environmental benefits that can
accrue from improving energy efficiency of single-family homes and using recycled/reused
materials as replacements for virgin materials in their construction. The analysis was focused on
how these strategies can help single-family homes perform better environmentally over their life
cycles. However, the benefits from implementing these two strategies extend beyond those that
can be measured purely by environmental impact categories to include economic and social
benefits.
As part of the U.S. EPA's commitment to integrate environmental justice principles and priorities
into the analyses, this section offers a discussion on how improving home energy efficiency and
increasing the recycling and reuse of materials associated with single family home construction
could positively affect disadvantaged communities. Improving the energy efficiency of homes
mitigates environmental pollution associated with electric utility services and also, can deliver
long-term savings to home owners and renters on energy bills. Increasing the recycling and reuse
of materials reduces the pollution associated with both the production of new materials and
54 For a narrative discussing opportunities to reduce housing costs in green construction, see Appendix I
64
-------
disposal of materials at their end of life, supports job creation and community revitalization, and
can reduce housing costs for low-income families.
5.4.1. Energy Efficiency
Increasing the energy efficiency of single family homes has the potential to mitigate
environmental pollution associated with electricity production and its effect on proximate,
typically low-income, communities. In addition, increasing energy efficiency of homes delivers
long-term savings on energy bills. For illustrative purposes, compared to standard homes, Energy
Star homes, which feature effective insulation, high-performance windows, tight construction and
ducts, efficient equipment and appliances, use substantially less energy for home heating, cooling,
and water heating and deliver $200 to $400 in annual savings on just these expenses.55
While some of the energy efficiency measures such as optimizing home-orientation or window
positioning may not come at additional costs, others, such as increasing the amount of insulation
or including more-efficient windows, may. However, Habitat for Humanity Metro Denver
partnered with the U. S Department of Energy's Building America Proj ect and the National
Renewable Energy Laboratory to create affordable, energy-efficient demonstration homes which
shows that certain energy efficiency features can be incorporated in cost-effective ways.56
5.4.2. Recycled and Reused Materials
Increasing the recycling and reuse of materials reduces the pollution associated with both the
production of new materials and disposal of materials at their end of life, supports job creation
and community revitalization, and can reduce housing costs for low-income families.
Pollution Reduction.
Material recovery diverts waste and intercepts the emissions associated with either the
incineration or the material break-down in landfills. In addition, the recovered materials replace
raw materials or finished products; thereby, the recovery intercepts the pollution associated with
the extraction and processing of virgin materials and the manufacture of new products.5? Even
though the pollution reduction improves the environment for all, benefits are the greatest for
disadvantaged, low-income communities that are often in the closest proximity to waste and
manufacturing facilities. These low-income households typically face cumulative pollution risks
as various waste and manufacturing facilities are often grouped together.
55 ENERGY STAR, Features & Benefits of ENERGY STAR Qualified New Homes:
http://www.energystar.gov/index.cfm?c=new_homes.nh_features: Accessed September 19, 2011.
56 Building America, U.S Department of Energy case studies: http://www.nrel.gov/docs/fy05osti/36102.pdf
and http://www.nrel.gov/docs/fy08osti/42591 .pdf. Accessed September 19, 2011.
57 U.S. EPA, Is recycling worthwhile:
http://waste.supportportal.com/ics/support/kb Answer.asp?deptID=23023&task=knowledge&questionID=l
9159. Accessed August 12, 2011.
65
-------
Job creation and community revitalization.
Incorporating recycled and reused materials supports the recycling and reuse industry, which
creates jobs58. According to The U.S. Recycling Economic Information Study, more than 56,000
recycling and reuse establishments in the United States employ approximately 1.1 million
people.59 Building materials recovery generally involves substantial activities around
deconstruction, sorting, salvage, value adding, stocking, and resale. Therefore, the contribution of
building material-recovery jobs to the overall recycling industry is significant.
Equally significant is the fact that recovered materials are typically sourced locally and that
therefore, any associated economic activity should directly benefit local communities. These
benefits range from creating local deconstruction, recovery, or resale jobs and providing low-cost
materials for local residents, to creating tax revenues and revitalizing communities at large.
Reduced housing costs.
The market for recovered materials primarily emerged from the growing awareness of the life
cycle impacts of new building materials. However, since recovered materials can function as
financial assets to lower construction and renovation costs for low-income-home builders and
home-owners, their value extends beyond just environmental protection. Pursuing affordable,
sustainable materials can improve the builder's bottom line and be an effective mechanism to
lower the upfront home or renovation costs for the owner.
The Building Material Reuse Association recently gathered industry representatives together at its
2011 convention, Decon ' 11 to speak about the value of deconstruction and material reuse.
Participants included appraisers and reuse consultants and designers. One of the repeatedly
mentioned benefits supported by industry examples was that deconstruction provided sustainable,
low-cost building materials.60 Along the same lines, the City of Seattle's Department of Planning
and Development published that recycling or reusing salvaged building materials as well as
58 The Tellus Institute in its report More Jobs, Less Pollution: Growing the Recycling Economy in the U.S.,
compared two hypothetical 2030 waste management scenarios; the baseline scenario that was developed on
continuing current practices to reach about 37-percent C&D waste diversion by 2030, and the Green
Economy scenario reflecting 75-percent C&D diversion through significantly enhanced recycling and
composting efforts. The Green Economy scenario generated more than twice the amount of jobs of the
baseline scenario demonstrating that the recycling jobs gained through enhanced diversion outnumber any
loss of jobs in C&D waste disposal, hi addition, in its study 2008 Employment Trends in N.C. 'S Recycling
Industry, the state of North Carolina looked at the recycling industry at large and found that job losses in
waste disposal and virgin materials mining and manufacture that directly result from recycling program
success, in North Carolina, were balanced or outweighed by job creation in the recycling sector.
59 U.S. EPA: http://waste.supportportal.com/link/portal/23002/23023/Article/18602/hc-there-is-plentv-of-
landfill-space-then-why-should-I-recvcle. Accessed August, 12, 2011.
60 For more information and copies of presentation slides, please see http://www.bmra.org/about-
bmra/newsupdates/323-decon-11 -presentations-are-available .
66
-------
minimizing materials and packaging, reduces material expenses.61 Reduced material expenses
translate into lower upfront housing costs as well as lower renovation/maintenance costs.
Differences in cost that exist between various recycled and reused materials reflect the value
added through the recovery process. In limited cases, this difference can result in a higher cost for
a recycled or reused material. However, funding may be available through the Low Income
Housing Tax Credit program to offset this incremental cost. State and local governments provide
funds based on how many points from their Qualified Allocation Plans the proj ects are able to
meet. States allocate points for green building practices, and a number of them allocate points for
recycled/reused materials.62 In such a case, incorporating recovered materials may help the
project qualify for funding that would in turn help the project team afford more sustainable
material choices for the needed applications.
Other Considerations
Health and safety considerations for recycled or reused materials.
Although building material reuse and recovery affords needed economic, social and
environmental benefits to society, concerns regarding human health and safety do exist. For
example, with material reuse and recycling, potentially harmful materials that had historically
circulated in the construction and maintenance of buildings (e.g. lead-based paint) could be
reintroduced into the housing stock, if not properly managed. From an environmental justice
perspective, of those materials, particular attention has been given to lead-based paint. Fighting
childhood lead-based paint poisoning has become one of the Department of Housing and Urban
Development (HUD)'s primary environmental justice initiatives.63 Through this initiative, HUD
provides public outreach and technical assistance and conducts technical studies to help protect
children and their families from health and safety hazards in the home.64
The U.S EPA also works to promote safe reuse and has gathered useful information to
communicate these issues.65 For example, in its Pollution Prevention and Toxics website, the
EPA specifically addresses the question of how reuse stores and their customers can manage the
lead-based paint hazards in older building materials. As a primary matter, the EPA notes that
states may have laws or regulations addressing the management, handling or sale of materials
61 Department of Planning and Development, City of Seattle, June 2005: Construction Waste Management
Guide for Architects, Designers, Developers, Facility Managers, Owners, Property Managers &
Specification Writers, p.2.
http://www.seattle.gov/dpd/cms/groups/pan/(g),pan/(g),sustainableblding/documents/web informational/dpds
007173.pdf. August 11, 2011.
62 Global Green USA, http://www.globalgreen.org/greenurbanism/affordablehousing/. Accessed August 15,
2011
63 U.S. Department of Housing and Urban Development, March 1995, Achieving Environmental
Justice - a Departmental Strategy:
http://www.hud.gov/offices/cpd/environment/library/subjects/justice/deptstrategv.cfm#b. Accessed August
15,2011.
64 U.S. Department of Housing and Urban Development, Healthy Homes and Lead Hazard Control,
http://portal.hud.gov/hudportal/HUD?src=/program ofFices/healthy homes. Accessed August 15, 2011.
65 U.S EPA, Pollution Prevention and Toxics, 2011: http://www.epa.gov/opptintr/. Accessed August
15,2011.
67
-------
containing lead-based paint, which would give very specific directions. Otherwise, the EPA
recommends that reuse stores at a minimum label suspect items to indicate that they may contain
lead, educate staff about lead hazards, and provide outreach materials to customers about lead-
safe work practices. The EPA also lists useful resources.66 While lead has taken center stage,
health and safety concerns may revolve around other materials and products as well. Unsafe
materials include asbestos, mercury, PCBs or arsenic.
It is also important to ensure that the chosen materials and products suit the application they are
intended to fill. For example, unless properly treated, salvaged lumber may not be suitable for
structural applications.67 Using recovered materials because of their low-cost, but without due
regard for functional suitability, could result in unsafe applications in affordable homes.
Additionally, some products may not be sufficiently efficient to provide healthy indoor conditions
or long-term cost-savings. For example, a single-pane window may be inexpensive and in usable
condition, but meanwhile, it is energy-inefficient in certain climates and thus, not a good,
affordable thermal solution for a home-owner in the long-run. However, such a window could
still be used in interior applications, e.g. a transom, where it could allow penetration of light into
secondary spaces such as hallways. Using salvaged materials in certain applications might not
meet the requirements of local building codes and it is most practical and protective for builders
and home-owners to consult local building officials and codes early.
Therefore, builders and home-owners who purchase building products for reuse should select
them judiciously in order to capitalize on their lower cost without j eopardizing the health and/or
safety of home-occupants. In that respect, additional inquiries and/or inspections may be
warranted around certain types of materials. The Department of Planning & Development of the
City of Seattle and the Department of Natural Resources and Parks of King County have created a
material index that lists various building items, recommends which ones should be recycled,
reused or disposed, and notes the associated environmental, health and safety concerns that justify
such recommendations.68
Durability and maintenance.
Interest in using recovered materials in new construction is not uniformly present across the
country. One common concern is that recycled or reused materials are inferior in quality and may
not be as durable. This perception is limiting the development of needed infrastructure to increase
the availability of these materials for affordable housing projects.
66 U. S EPA, Pollution Prevention and Toxics, 2011, Frequent Questions, General Information about Lead,
2011: http://toxics.supportportal.com/link/portal/23002/23019/Article/32411/Building-material-reuse-
stores-sometimes-accept-older-materials-which-have-been-coated-with-lead-based-paint-and-could-pose-a-
lead-poisoning-hazard-In-particular-older-windows-and-doors-are-likelv-to-. Accessed August 15, 2011.
67 King County Department of Natural Resources and Parks, Solid Waste Division & City of Seattle
Department of Planning and Development, 2006. {Green ho me remodel} salvage & reuse:
http://vour.kingcountv.gov/solidwaste/greenbuilding/documents/Green home remodel-salvage.pdf.
Accessed August 15, 2011.
68 Ibid.
68
-------
However, the U.S EPA has published that recycled materials contain similar chemical and
physical properties as the virgin materials they replace, and when used according to appropriate
environmental regulations engineering specifications, provide comparable—and in some cases,
superior—performance at a lower cost.69
The Department of Planning & Development of the City of Seattle and the Department of Natural
Resources and Parks of King County both advocate that salvaged materials cost less and last
longer: their longevity is especially evident when building materials are salvaged from the
structures of the periods that boasted construction of better quality.70
The USGBC consistently encourages the use of salvaged or reused building materials in single
family home construction. The USGBC does not specifically recommend any additional
operations and maintenance considerations pertaining to reused materials.71 However, the
USGBC does point out that the recycled-content materials may require different maintenance
than conventional products. Homeowners should be made aware of any specific maintenance
requirements in order to delay and minimize repairs. However, the USGBC's caution that
recycled-content materials may require specific upkeep should not be interpreted to imply that
these materials would not last long or perform as is expected.
The performance requirements of building codes may on the outset determine the expected levels
of maintenance and durability for the materials that are alternative to conventional. Accordingly,
the recycled/reused product suppliers may warranty the product performance to ensure a customer
base. Such warranties might sufficiently address any durability concerns for designers, builders
and owners. In any case, designers, builders and owners must ensure that recovered materials
meet applicable building codes and laws.
Planning considerations.
If the process to include reclaimed materials is to be successful, so that any benefits for low-
income households could accrue, builders and homeowners should be aware that the construction
process is not traditional and that additional planning steps are needed. Guidelines from industry
practitioners and local governments and technical assistance are available to make this process
more predictable. For example, considering that the material availability fluctuates, guidelines
suggest that it is necessary to keep a flexible design and schedule. Flexibility will allow the
designers/builders to investigate the market and capitalize on the safe, affordable materials as
they become available. However, because the prospective materials will not all come at the same
time, the designers/builders will need to provide spaces for their proper storage on-site. On the
69 U.S. EPA, Office of Resource Conservation and Recovery, March 2009. Estimating 2003 Building
Related Construction and Demolition Materials Amounts, p. 21.
70 King County Department of Natural Resources and Parks, Solid Waste Division & City of Seattle
Department of Planning and Development, 2006. {Green ho me remodel} salvage & reuse:
http://vour.kingcountv.gov/solidwaste/greenbuilding/documents/Green home remodel-salvage.pdf.
Accessed August 15, 2011.
71 U.S. Green Building Council, Green Building Design and Construction, LEED Reference Guide for the
Design, Construction and Major Renovations of Commercial and Institutional Buildings Including Core
and Shell and K-12 School Projects, 2009 Edition (Updated June 2010), p. 367 and 375.
69
-------
side of design though, reliance on random local materials that are available during construction
will most likely result in unique structures and creative material patterns and applications72 that
could be aesthetically valuable in affordable housing.
72 Olivia Chen, Affordable Housing Made of Recycled Materials: http://inhabitat.com/low-income-housing-
made-of-recvcled-materials/. Accessed September 16, 2011.
70
-------
6. SUMMARY OF FINDINGS AND CONCLUSIONS
This life cycle analysis presents a national, economy-wide strategic view of the environmental
impacts associated with the construction, use, and demolition/deconstruction of single-family
homes. The input contribution analysis identified the materials, products, and services directly
consumed during the construction and use of single-family homes ("direct inputs") that contribute
most significantly to overall life cycle environmental impacts. The output contribution analysis
holistically identified the upstream supply chain processes in the economy where the most
significant sources of life cycle environmental impacts associated with single-family homes
occur.
The supply chains associated with selected direct inputs to single-family homes were explored in
greater detail to provide further insights into the sources of embodied environmental impacts
associated with these inputs. In addition, the potential for avoiding life cycle impacts associated
with single-family homes was assessed by analyzing the energy efficiency and recycling/reuse
scenarios. A brief summary of the results of these analyses is presented below. More in-depth
summaries are presented in Sections 3 through 5.
6.1 SUMMARY OF FINDINGS
6.1.1 Overall life cycle impacts of single-family homes
The analysis of overall life cycle impacts associated with single-family homes indicates the
majority of life cycle impacts associated with single-family homes occur during the occupancy
phase. This finding holds across all impact categories with the exception of the material input
category, where the majority of impacts occur during the pre-occupancy phase. Life cycle
impacts associated with the post-occupancy phase are relatively insignificant for all but the waste
impact category. However, this should not be interpreted as a finding that choices regarding the
management of building demolition/ deconstruction material have an insignificant effect on the
life cycle impacts of single-family homes. Rather, the finding reflects a definitional issue, and the
recycling and/or reuse of C&D material can result in significant avoided impacts when used as an
input in the residential building and other sectors of the economy.
For the pre-occupancy and occupancy phases, most of life cycle impacts associated with single-
family homes are indirect—they result from upstream supply chain processes and are embodied
in the direct inputs to the single-family home. This suggests that a policy perspective focused
solely on direct inputs without an understanding of the upstream supply chain processes and the
economic linkages among inputs and upstream processes may miss opportunities for effectively
reducing the environmental impacts associated with single-family homes.
71
-------
6.1.2 Direct Inputs — Pre-Occupancy and Occupancy Phases73
The input contribution analysis for the pre-occupancy phase of single-family homes suggests that
when all factors are considered equally (no weighting or grouping), a diverse mix of direct inputs
contributes to the overall life cycle impacts of single-family homes, including building materials
(e.g., brick and structural clay tile, ready-mixed concrete, reconstituted wood products), more
highly engineered products (e.g., miscellaneous plastic products), and services (e.g., trucking and
courier services').
Construction materials, including sand and gravel, dimension, crushed and broken stone, ready-
mixed concrete, and reconstituted wood products, tend to contribute most significantly to the life
cycle natural resource and land use impacts. Brick and structural clay tile contributes most
significantly to the toxicity-related life cycle impacts associated with single-family homes.
Ready-mixed concrete, fiber glass and mineral wool insulation, and reconstituted wood products
accounted for significant contributions to the life cycle pollution impacts associated with single-
family homes.
The input contribution analysis for the occupancy phase of single-family homes was focused on
energy and water inputs and materials and products replaced during the life span of the home.
Energy consumption and impacts associated with electricity contribute the most to the life cycle
impacts associated with the occupancy phase of single-family homes. More than half of the
overall life cycle impact of single-family homes for 8 of the 17 impact categories is associated
with electric services. In terms of replacements, wood shingle siding, and fiberglass and mineral
wool insulation contribute significantly to life cycle impacts of single-family homes.
6.1.3 Supplemental Analysis of Selected Inputs
Supplemental supply chain analyses focused on fiberglass and mineral wool insulation, ready-
mixed concrete, wood shingle siding, reconstituted wood products, and brick and structural clay
tile. The analysis identified a close relationship between the upstream supply chain processes
associated with forestry products and the land use impacts associated with wood shingle siding
and the upstream supply chain processes associated with hydraulic cement and the pollution
impacts associated with ready-mixed concrete.
The analysis also found that for some products categories, the manufacturing phase of the product
itself accounted for a significant portion of the life cycle impacts associated with the product. It is
estimated that the manufacturing of fiberglass and mineral wool insulation accounts for almost
half of the ODP impacts associated with these products, the manufacturing of ready-mixed
concrete is an important source of pollution impacts, and the manufacturing of brick and
structural clay tile accounts for almost half of important life cycle toxicity impacts of single-
family homes.
73 Contribution analyses were not conducted for the post-occupancy phase due to the limited scope and
constribution of impacts associated with this phase relatively to the overall life cycle impact associated with
single-family homes. See Section 2.3 for additional discussion.
72
-------
The analysis highlighted the significance of electric services and other energy-related upstream
supply chain processes to the life cycle impacts embodied in direct inputs to single-family homes.
This contribution was particularly evident in the analyses of the ready-mixed concrete and
reconstituted wood products product categories. Finally, the findings with respect to the
contribution of forestry to land use competition impacts and the potential for managed forests to
sequester carbon highlighted the importance of weighing multiple factors (e.g., land use and
global warming potential) when evaluating policy responses.
6.1.4 Upstream Supply Chain Processes
Whereas the input contribution analysis focused on the relative contribution of direct inputs to the
overall life cycle impacts, the output contribution analysis disaggregated these impacts to their
original source in the upstream supply chain of single-family homes. The output contribution
analysis was conducted for the pre-occupancy and occupancy phases of single-family homes.
Relative to the input contribution analysis, the output contribution analysis highlighted energy
and related supply chain processes, raw construction and other materials used in single-family
homes and transportation, for their contribution to the overall life cycle impacts of single-family
homes.
The pre-occupancy phase output contribution analysis highlighted materials associated with new
building construction (e.g., brick and structural clay tile, sand and gravel, and dimension,
crushed and broken stone). The occupancy phase output contribution analysis differed in that it
highlighted supply chain processes associated with replacement materials, agriculture, forestry,
and fishery services, paper and paperboard mills, and. plastics materials and resins as inputs to
wood products. Both analyses identify fiberglass and mineral wool insulation as a significant
contributor to the overall life cycle impact of single-family homes.
Processes contributing significantly to the overall natural resource and land use impacts of single-
family homes included, in the pre-occupancy phase, sand and gravel, crude petroleum and
natural gas, coal, and dimension, crushed and broken stone, and in the occupancy phase, energy-
related inputs (e.g., electric services, coal, and crude petroleum and natural gas), and forestry
services. Processes contributing significantly to the overall toxicity impacts of single-family
homes included, in the pre-occupancy phase, brick and structural clay tile, and in the occupancy-
phase, electric services, chemicals, and pulp and paper mills. Both the pre-occupancy- and
occupancy-phase output contribution analyses highlight electric services as a primary contributor
to impacts included in the pollution grouping.
6.1.5 Potential for Avoided Impacts
The input and output contribution analyses indicated that a diverse mix of inputs contribute
significantly to the life cycle impacts associated with single-family homes. Additional analyses
were conducted to analyze the potential for avoiding impacts through reduced material and
resource use. These included analysis of avoided impacts associated with the following scenarios:
73
-------
• Improving end-use efficiency of electricity use for space heating, water heating, space
cooling, refrigeration, and lighting;
• Improving end-use efficiency of natural gas use for space heating and water heating;
• Increasing the recycling of ready-mixed concrete from single-family home demolition as
roadway aggregate;
• Increasing the recycling of carpets and rugs salvaged during the renovation or demolition/
deconstruction of single-family homes as resin for various synthetic materials;
• Increasing the reuse of brick salvaged from single-family homes for new construction;
and
• Increasing the recycling of reconstituted wood products as a source of energy for the
wood and paper products industries.
The results of the avoided impacts analysis suggest that, combined, the energy efficiency
improvements and material reuse/recycling scenarios considered in the avoided impacts analysis
could result in 5-28% reductions in the life cycle impacts associated with single-family homes.
Improving efficiencies in lighting, space heating, space cooling and water heating could result in
reductions of 12-27% in the life cycle impacts associated with single-family homes across a range
of natural resource use, toxicity, and pollution impact categories. The analysis suggests that the
most significant contributions to avoided impacts would result from the efficiency improvements
in natural gas water and space heating, lighting, and electric space cooling.
Improvements in material reuse and recycling rates considered in the analysis could result in
reductions of 6-14% in life cycle impacts associated with single-family homes across a range of
natural resource, toxicity, and pollution impact categories. The analysis suggests that the
recycling scenario analyzed for carpets and rugs accounted for most of the potential avoided
impacts, including 9-13% reductions in life cycle stratospheric ozone depletion and three
categories of ecotoxicity impact. The analysis suggests that the increased recycling of salvaged
reconstituted wood products as an energy source could offset 7% of life cycle abiotic depletion
and 5% of the life cycle waste impacts associated with single family homes. The analysis
suggested that while reductions in life cycle impacts could be achieved through increased
recycling of concrete and reuse of brick, the contribution of the scenarios considered to reducing
overall life cycle impacts associated with single-family homes would be relatively small.
However, it is important to note that even if an impact for a single material could be small, the
sum of such small impacts across the many materials used in building a home should result in
more significant environmental savings overall.
6.1.6 Environmental Justice
The two avoided impact scenarios quantified the environmental benefits that can accrue from
using recycled/reused materials as replacements for virgin materials and improving energy
efficiency. The analysis demonstrated how these strategies can help single-family homes perform
better environmentally over their life cycles. However, the benefits from implementing the two
strategies extend beyond ones that can be measured purely by environmental impact categories.
Broadly, through the reduction of pollution that most affects low-income households and their
74
-------
potential to reduce housing costs, incorporation of recovered materials and energy efficiency
improvement strategies provide social, health and economic benefits to disadvantaged
communities. Other co-benefits that result from increasing the recycling and reuse of materials
include job creation in local deconstruction and recycling/reuse industries as well as overall
community revitalization from any associated economic activity.
Recovered materials are often cheaper and their increased incorporation can help reduce both
upfront and renovation housing costs in attempts to provide and maintain affordable, green
homes. However, for recovered materials to be of service to low-income households in affordable
housing, they need to be chosen judiciously. One concern is that potentially harmful materials
that had historically circulated in the construction and maintenance of buildings could be
reintroduced. The US EPA works to promote safe reuse and has gathered useful information on
how reuse stores and their customers can safely manage older building materials that may contain
lead-based paint.74
Further, depending on the application, the structural and energy-efficiency performance of
recovered materials may be other important criteria for their selection. Building codes may not
allow salvaged lumber for structural applications due to safety concerns, or a salvaged single-
pane window for exterior applications due to energy inefficiency.75
Finally, for repair and maintenance costs not to overcome the upfront savings, recovered
materials need to be sufficiently durable. Materials salvaged from the structures of periods that
boasted construction of better quality may be preferential.76
6.2 CONCLUSIONS
The analysis of the life cycle impacts associated with single-family homes demonstrates the
importance of considering a broad range of life cycle impacts in the evaluation of environmental
issues and mitigation responses.
6.2.1 The Use of Life Cycle, Multi-Impact Analysis in Support of SMM
This analysis demonstrates the importance of approaching environmental issues from a life cycle
perspective and the importance of considering multiple impacts of concern. The analysis provides
insights that could not be gleaned from a more narrow perspective—e.g., insights regarding
74 U. S EPA, Pollution Prevention and Toxics, 2011, Frequent Questions, General Information about Lead,
2011: http://toxics.supportportal.com/link/portal/23002/23019/Article/32411/Building-material-reuse-
stores-sometimes-accept-older-materials-which-have-been-coated-with-lead-based-paint-and-could-pose-a-
lead-poisoning-hazard-In-particular-older-windows-and-doors-are-likelv-to-. Accessed August 15, 2011.
75 King County Department of Natural Resources and Parks, Solid Waste Division & City of Seattle
Department of Planning and Development, 2006. {Green ho me remodel} salvage & reuse:
http://vour.kingcountv.gov/solidwaste/greenbuilding/documents/Green home remodel-salvage.pdf.
Accessed August 15, 2011.
76 Ibid.
75
-------
relationships among life cycle phases, across environmental media, and across human and
ecological receptors.
For example, in the context of life cycle impacts associated with single-family homes, the
analysis demonstrates:
• Different patterns emerge when analyzing impacts across the supply chain. For example:
o For some materials, products and services, a very clear link exists between
embodied impacts and upstream supply chain processes (e.g., reconstituted wood
products and forestryproducts and wood milling processes).
o In other cases, the patterns are less clear reflecting situations where an end-
product embodies impacts derived from a diverse range of upstream supply chain
processes (e.g., miscellaneous plastic products) or situations where a supply
chain process contributes to overall life cycle impact through a diverse set of
direct inputs (e.g., electrical services).
o Still in other cases, the manufacturing of the product itself creates much of the
impact with little contribution from upstream supply chain processes (e.g.,
fiberglass and mineral wool insulation).
• Different patterns emerge when analyzing impacts across different impact categories. For
example:
o Some materials, products, and services contribute significantly to overall life
cycle impact due to one or two dominant impacts (e.g., sand and gravel and the
material input and waste impact categories).
o Some materials, products, and services contribute significantly to overall life
cycle impacts through a diverse set of impacts (e.g., electrical services,
reconstituted wood products').
o Other materials, products, and services contribute to overall life cycle impacts
based on a diverse but related set of impacts (e.g., ready-mixed concrete and
pollution impacts).
• Different patterns emerge when analyzing impacts across life cycle phases. For example:
o The relative significance of different materials, products, and services to overall
life cycle impact may change depending on life cycle phase (e.g., construction
materials contribute more significantly to life cycle impacts in the pre-occupancy
phase). Other materials continue to contribute to the overall life cycle impacts of
single-family homes through the life cycle (e.g., wood shingle siding used in
original construction and replaced during the life span of a home).
o Different life cycle phases can contribute more or less significantly to different
life cycle impacts. For example, energy consumption during the occupancy phase
accounts for the majority of overall life cycle energy consumption associated
with single-family homes. Material input during the pre-occupancy phase
76
-------
accounts for the majority of overall life cycle material inputs associated with
single-family homes.
6.2.2 Opportunities for Integrated Environmental Decision-Making in Support of
SMM
The analysis also suggests the potential for multiple, reinforcing environmental benefits that
could be achieved when mitigation is approached from an integrated environmental decision-
making perspective. It demonstrates relationships among supply chain processes and suggests the
interconnectivity among producers, service providers, and consumers—individuals, businesses,
and governments—in the economy. The life cycle perspective suggests that policy interventions
could occur at multiple stages in a supply chain and involve multiple actors and policy
instruments. The multi -impact perspective suggests that government programs focused on
different objectives could work in tandem to address disparate issues with common solutions. A
multi-impact life cycle perspective provides a foundation for integrated environmental decision-
making.
For example, in the context of single family homes, the analysis demonstrates the following
insights with respect to integrated environmental strategies:
• Impact patterns across supply chains suggest the types of policy responses. For example:
o Where direct or embodied impacts tend to accumulate around a limited set of
supply chain processes, a set of policy responses directed specifically at those
points in the supply chain might be more effective than a cross-supply chain
response.
• Different impact patterns across impact categories suggest different type of policy
responses. For example:
o Where a material, product, or service contributes significantly to overall life
cycle impacts through a diverse set of impact categories, a coordinated response
among environmental programs, using different authorities, could yield
efficiencies in addressing impacts and avoid the shifting of impacts from one
medium/receptor to another.
o Where a material, product, or service contributes significantly to overall life
cycle impacts through a limited set of impact categories, a directed response
through a single program or using a more limited set of authorities might be more
effective.
• When analyzing potential approaches to more sustainable materials management, it is
important to consider inter-relationships across life cycle boundaries. For example:
o Where the analysis indicates significant impacts associated with the use phase, it
is important to consider not only policy strategies focused on use but also
opportunities to avoid use phase impacts through, for example, improvements in
77
-------
product design (e.g., use of more durable construction), alternative product-
service systems, etc.
o It is important to consider opportunities to preserve natural capital by reusing and
recycling materials at the end-of-life as inputs to upstream supply chain
processes associated with production or use phases (e.g., reuse of bricks or
hardwood flooring) and to consider opportunities for avoiding impacts in another
economic sector (e.g., recycling of concrete as roadway aggregate, recycling of
wood panels as fuel).
6.2.3 Analytical Tools in Support of SMM
Input-Output Life Cycle Analysis (I-O LCA) is inclusive of an infinite number of production
processes and circular effects along their way. The data that the I-O LCA approach uses are the
most detailed and complete US life cycle inventory data. Consequently, the I-O LCA is
increasingly becoming part of decision-making processes.
However, input-output data as detailed as they may be, generally, have some limitations that
could reduce the certainty of findings of I-O LCA models. Examples of such data limitations
include source data uncertainties, aggregation uncertainties and international production
uncertainties:77
1. Source data uncertainties. Input-output data are publicly available data that were
collected through business surveys and later transformed; the standard error typically
linked to surveys is obscured with these later data transformations.78
In addition, not all possible environmental impacts are represented by the data. For
example, to minimize reporting burdens, information such as the use of fertilizers is not
collected at the national level.79 This being the case, nutrient and organic matter fluxes
associated with forestry will be omitted and the impacts embodied in e.g., dimensional
lumber will not be completely characterized.
2. Aggregation uncertainties. Products are grouped in a single sector if their making
requires similar processes. In instances in which data for dissimilar products are
aggregated in one sector, one product may incorrectly endow contributions and embody
impacts of upstream processes of another product. For example, non-cotton-based and
cotton-based products are aggregated in Carpet and Rug Mills Industry. Because of the
aggregation, non-cotton-based products such as residential carpets and rugs, embody
environmental impacts of cotton cultivation; see Section 3.1.1 About Carpets and Rugs
11 For an expanded list of uncertainties and further explanation, see: 1. Manfred Lenzen, Errors in
Conventional and Input-Output-based Life-Cycle Inventories, Journal of Industrial Ecology, Volume 4,
Number 4; and 2. Eric D. Williams, Christopher L. Weber, and Troy R. Hawkins, Hybrid Framework for
Managing Uncertainty in Life Cycle Inventories, Journal of Industrial Ecology, Volume 13, Number 6
78 Manfred Lenzen, Errors in Conventional and Input-Output-based Life-Cycle Inventories, Journal of
Industrial Ecology, Volume 4, Number 4
79 Carnegie Mellon, Green Design Institute: Limitations of the EIO-LCA Method and Models,
http://www.eiolca.net/Method/Limitations.html, Accessed January 03, 2013.
78
-------
and Cotton. This occurrence makes it difficult to model a specific product. In addition,
data may also be combined based on similar end-products even if the production
processes are different, and such occurrence makes it difficult to model a specific
industry.
3. International production uncertainties. US input-output tables detail environmental
impacts of manufacturing processes of US facilities. The I-O LCA approach assigns
those same impacts to imports also, if the modeled applications are based in the US; e.g.,
Chinese drywall used in US single-family homes. However, globally, technology,
manufacturing processes and environmental regulations differ. Accordingly, uncertainty
is associated with the assumption that an imported product will use the same resources
and create same environmental releases as its US counterpart.
In addition, I-O data are averaged out across the national economy so that I-O LCA findings are
not applicable in local contexts.
Importantly though, data uncertainties do not imply that I-O LCA studies are unreliable;80
however, to present and interpret the findings, these uncertainties should be understood and the
ultimate nature of the I-O LCA results recognized. In this particular case, instead of governing a
specific, sustainable way to produce a single-family home, I-O LCA points to where additional
efforts could be focused so as to begin to develop approaches to a sustainable management of
single-family homes. For example, where a product category that encompasses a diverse range of
products contributes significantly to life cycle impacts (e.g., miscellaneous plastic products), the
analysis suggests that supplemental research, comparison with previous studies and
complementary analyses (e.g., process LCA) be conducted to better understand the nature of
these impacts. Where the analysis shows significant potential for avoided impacts, it suggests
additional research, stakeholder convening, and/or other activities to validate the finding and
understand the feasibility and possible strategies for capturing this potential. The feasibility
analysis may include assessment of the availability of techniques to produce less impactful inputs,
e.g., a less-impactful ready-mixed concrete.
6.2.4 Additional Studies Others Could Undertake
I-O LCA provides a unique and thorough perspective in support of national-level, strategic
studies of the nature, source, and locus of life cycle impacts associated with a key area of
economic activity. I-O LCA allows for an effective and efficient analysis based on thorough sets
of economic data and a multi-perspective, multi-impact view and is increasingly becoming part of
decision-making processes.
Nevertheless, I-O LCA can and should be improved. Providing certainty analyses in association
with I-O LCA studies could help identify specific I-O data limitations so they could be corrected.
For example, follow-on studies focusing on uncertainty others could undertake could result in the
disaggregation of the Carpet and Rug Mills Industry in the I-O table into cotton-based and non-
80 Eric D. Williams, Christopher L. Weber, and Troy R. Hawkins, Hybrid Framework for Managing
Uncertainty in Life Cycle Inventories, Journal of Industrial Ecology, Volume 13, Number 6
79
-------
cotton-based products made by the sector. This would improve the I-O data and the certainty
associated with the data going forward.
Follow-on tasks others could undertake are to:
1. Provide complementary analyses using process-based LCA datasets and software such as
Ecolnvent, GaBi, and/or BEES, and critically compare findings to the findings included
herein;
2. Research literature for other more narrowly focused studies, e.g., another LCA study
could have the scope that is a subset of the scope of this report, and critically compare
findings to the findings included herein;
3. For products of interest, examine specific life cycle elementary flows that are
contributing to the high impact as well as the original data sources used to characterize
those impacts, and identify if data may be generating overestimates;
4. Research I-O database independently to identify potential areas of data aggregation that
could be influencing findings of interest, and highlight if the data that may be generating
spurious findings.
80
-------
Glossary of Key Terms
Abiotic depletion potential (ADP) - the annual rate of depletion of the stock of minerals and fossil
fuels (natural resources that are regarded as non-living) relative to ultimate reserves. See also
Appendix Bl.
Acidification potential (AP) - impact of human emissions of acidifying substances (e.g., SCh,
NOx, NHx) on soil groundwater, surface waters, biological organisms, ecosystems, and built
infrastructure. See also Appendix Bl.
Characterization - modeling life cycle impacts. Characterization models are used to express
impacts in terms of common characterization factors that allow aggregation of environmental
emissions using equivalent terms (Suh, 2004; EPA, 2006).
Construction and demolition (C&D) materials - materials are generated when new structures are
built and when existing structures are renovated or demolished (including deconstruction) (EPA,
2003 a).
Contribution analysis - analysis of the contribution of impacts associated with direct inputs or
upstream supply chain processes to the overall life cycle impact of the material, product, or
service under study, within or across life cycle phases (Heijungs and Suh, 2002). See also input
contribution analysis and output contribution analysis.
Cradle-to-gate - the life cycle of a product or service from the point of resource extraction to the
"factory gate," or the point at which it is sold or, in some cases, consumed (Heijungs and Suh,
2002). For this analysis, it is equivalent to the pre-occupancy phase.
Deconstruction - the systematic dismantling of a building in an attempt to recover as much
material as possible (EPA2003a). Compare to demolition.
Demolition - the removal of the building through mechanical means in an attempt to remove the
building as quickly and inexpensively as possible (EPA 2003a). Compare to deconstruction.
Direct environmental impact - impact that results during the extraction of material, production of
the product, or delivery of service under study or impact that occurs during the life cycle phase
under study. Used to describe specific direct environmental impacts (e.g., global warming, human
toxicity) or a combination of direct environmental impacts and direct resource withdrawals (e.g.,
water consumption). Compare to indirect impact. See also Appendix B2.
Direct input - material, product or service directly consumed by the material, product, or service
under study. Compare to indirect input. See also Appendix B2.
Direct resource withdrawal - resource withdrawal (e.g., water consumption, material input) that
occurs during the extraction of the material, production of the product, or delivery of the service
under study. Compare to indirect resource withdrawal. See also Appendix B2.
Ecotoxicity - the effects of chemical emissions on fish, wildlife, plants, and other wild organisms.
Embodied environmental impact - environmental impacts associated with upstream supply chain
processes (i.e., indirect impacts) plus impacts associated with the extraction of the material,
production of the product, or delivery of the service under study (i.e., direct impacts'). Used to
81
-------
describe specific environmental impacts (e.g., global warming, human toxicity) or a combination
of environmental impacts and resource withdrawals (e.g., water consumption).
Embodied resource withdrawal - resource withdrawal (e.g., energy consumption, material input)
associated with upstream supply chain processes (i.e., indirect resource withdrawals') plus
resource withdrawals associated with the extraction of the material, production of the product, or
delivery of the service under study (i.e., direct resource withdrawal).
Energy consumption (EC) - total net primary energy consumption, including consumption of
fossil fuels, nuclear energy, and renewable energy (not including geothermal energy). See also
Appendix Bl.
Eutrophication potential (EP) - impact of high environmental levels of macronutrients, the most
important of which are nitrogen (N) and phosphorus (P), in terms of excessive nutrient
enrichment and shifts in species composition and elevated biomass production in aquatic and
terrestrial ecosystems. See also Appendix Bl.
Freshwater aquatic ecotoxicity potential (FAETP) - impact of toxic substances on freshwater
aquatic ecosystems. See also Appendix Bl.
Freshwater sediment ecotoxicity potential (FSETP) - impact of toxic substances on the sediment
of freshwater aquatic ecosystems. See also Appendix Bl.
Global warming potential (GWP) - impact of human emissions on the radiative forcing of the
atmosphere. See also Appendix Bl.
Human toxicity potential (HTP) - impact on human health of toxic substances present in the
environment (i.e., excluding workplace exposures). See also Appendix Bl.
Indirect environmental impact - impact associated with upstream supply chain processes. Used to
describe specific indirect environmental impacts (e.g., global warming, human toxicity) or a
combination of indirect environmental impacts and indirect resource withdrawals (e.g., water
consumption). Compare to direct impact. See also Appendix B2.
Indirect input - upstream supply chain process associated with the material, product, or service
under study. Compare to direct input. See also Appendix B2.
Indirect resource withdrawal - resource withdrawal (e.g., water consumption, material input)
associated with upstream supply chain processes associated with the material, product, or service
under study. Compare to direct resource withdrawal. See also Appendix B2.
Input contribution analysis - analysis of the contribution of impacts associated with direct inputs
to the overall life cycle impact of the material, product, or service under study, within or across
life cycle phases (Suh 2003). See also contribution analysis and output contribution analysis.
Input-output life cycle analysis (I-O LCA) - life cycle analysis employing detailed input-out data
regarding the economic transactions between industries within an economy to model supply chain
resource requirements, environmental emissions, and environmental impacts associated with a
particular material, product, or service
Integrated environmental decision-making - an approach to environmental problems that
involves holistic thinking, informed synthesis and elicitation of public environmental values, and
82
-------
application of tools and procedures to evaluate multi-dimensional risks, in order to maximize the
efficient reduction of aggregate risk to populations or ecological systems (EPA 2000).
Land use competition (LUC) - loss of land as a resource, in the sense of being temporarily
unavailable for other uses, due to human use. See also Appendix Bl.
Life cycle analysis (LCA) - an approach for estimating the cumulative environmental impacts
resulting from all stages of the life cycle of a material, product, or service from the perspective
that they are interdependent (EPA 2006).
Life cycle emissions - the releases of chemical substances to air, water, or land aggregated over
the life cycle of a material, product, or service. In this context, the term "emissions" extends
beyond air emissions and includes water discharges, land disposal, etc.
Life cycle environmental impact - impact associated with life cycle environmental emissions
and/or impacts associated with a combination of life cycle environmental emissions and life cycle
resource withdrawals.
Life cycle resource withdrawal - resource withdrawal (e.g., water consumption, land use, energy
consumption, material consumption) aggregated over the life cycle of a material, product, or
service.
Marine aquatic ecotoxicity potential (MAETP) - impact of toxic substances on marine aquatic
ecosystems. See also Appendix Bl.
Marine sediment ecotoxicity potential (MSETP) - impact of toxic substances on the sediment of
marine aquatic ecosystems. See also Appendix Bl.
Material input (MIL) - raw materials required to produce a commodity, including
domestically extracted and imported raw materials, less processing wastes and exports of
processed materials. See also Appendix Bl.
Occupancy phase - the phase of the life cycle of a single-family home when the home is in use,
extending from the end of i\\e pre-occupancy phase to the time at the beginning of fas post-
occupancy phase, including periods when the home is vacant between occupants.
Output contribution analysis - analysis of the contribution of impacts associated with upstream
supply chain processes to the overall life cycle impact of the material, product, or service under
study (Suh, 2003). See also contribution analysis and input contribution analysis.
Photochemical ozone creation potential (POCP) - impact of human emissions of volatile organic
compounds (VOCs) and carbon monoxide (CO) in the presence of nitrogen oxides (NOx)
resulting in the formation of reactive chemical compounds, including ozone, by the action of
sunlight. See also Appendix Bl.
Post-occupancy phase - the period when the single-family home is demolished or deconstructed,
extending from the end of the occupancy phase to the end-of-life of the materials that previously
constituted the structure.
Pre-occupancy phase - the period extending from the extraction of raw materials associated with
the supply chain of a single-family home through the time when the home is being built and
ending at the start of the occupancy phase.
83
-------
Process life cycle analysis (LCA) - an approach to life cycle analysis that involves summing life
cycle impacts across unit process models to obtain total life cycle impact, -where unit processes
are defined as the smallest portion of a product system for which data are collected (Hendrickson
etal.,2006).
Radiative forcing - the change in the balance between solar radiation entering the atmosphere and
the Earth's radiation going out. On average, a positive radiative forcing tends to warm the surface
of the Earth while negative forcing tends to cool the surface. Greenhouse gases have a positive
radiative forcing because they absorb and emit heat (IPCC, 2001).
Replacements - materials and products substituted for materials and products originally installed
in the single-family home or providing/enhancing the function of the original materials and
products, after these original materials and products have been removed, including parts of the
structure (e.g., roofing shingles, doors and windows), materials used to protect and/or improve the
function of structure (e.g., rugs, insulation), and appliances (e.g., washing machines, heaters).
Stratospheric ozone depletion potential (ODP) - Impact of anthropogenic emissions on the
thinning of the stratospheric ozone layer, resulting in a greater fraction of solar UV-B radiation
reaching the earth's surface. See also Appendix Bl.
Supply chain process - a process in the supply chain of a material, product, or service provided to
the end consumer, where the supply chain consists of the network of all materials extraction
processes, product production processes, and services required to meet the consumer's need. See
also upstream supply chain process.
Sustainable materials management (SMM) - an approach to promote sustainable materials use,
integrating actions targeted at reducing negative environmental impacts and preserving natural
capital throughout the life-cycle of materials, taking into account economic efficiency and social
equity (OECD, 2005).
Terrestrial ecotoxicity potential (TETP) - Impact of toxic substances on terrestrial ecosystems.
See also Appendix Bl.
Upstream environmental impact - impact associated with upstream supply chain processes. Used
to describe specific indirect environmental impacts (e.g., global warming, human toxicity) or a
combination of indirect environmental impacts and upstream resource withdrawals (e.g., water
consumption). Compare to direct impact. See also indirect environmental impact.
Upstream resource withdrawal - resource withdrawal (e.g., water consumption, material input)
associated with upstream supply chain processes associated with the material, product, or service
under study. Compare to direct resource withdrawal. See also indirect resource withdrawal.
Upstream supply chain process - a process in the supply chain of a material, product, or service
provided to the end consumer, where the supply chain consists of the network of all materials
extraction processes, product production processes, and services required to meet the consumer's
need. See also supply chain process.
Waste (WST) - Materials that are consumed in the U.S. economy and exit (e.g., through
disposal in a landfill) within 30 years after entry. See also Appendix Bl.
84
-------
Water consumption (WC) - Total water used by operation or facility, including: for agriculture,
total water used in irrigation; for commercial/industrial sectors, net intake plus water re-
circulated; and for electricity generation, total water used in thermoelectric (in-stream and off-
stream) and hydropower facilities (in-stream). See also Appendix Bl.
85
-------
Units of Measure Used in This Report
Btu - British thermal units
CW& eq. - ethylene equivalents, expressed in terms of kilograms (kg CJrU eq.)
CFC-11 eq. - trichlorofluoromethane (also known as CFC-11) equivalents, expressed in terms of
kilograms (kg CFC-11 eq.)
COieq. - carbon dioxide equivalents, expressed in terms of kilograms (kg CCheq.)
p-DCB eq. - 1,4-dichlorobenezene (also known as p-dichlorobenzene) equivalents, expressed in
terms of kilograms (kg p-DCB eq.) or metric tons (niton p-DCB eq.)
MJ- megajoules
kg - kilograms
m2 *yr - square meter years
mton - metric ton, equivalent to 1,000 kilograms
PO4 eq. - phosphate equivalents, expressed in terms of kilograms (kg PO4 eq.)
Sn eq. - antimony equivalents, expressed in terms of kilograms (kg Sn eq.)
SO2 eq. - sulfur dioxide equivalents, expressed in terms of kilograms (kg SCh eq.)
86
-------
List of References
Athena Institute (2002). Maintenance, Repair and Replacement Effects for Building Envelope
Materials. Athena Sustainable Material Institute: Merrickville, ON, Canada
Boyano Larriba, A. and O. Wolf (2010). Analysis and Evaluation of 3rd Draft Criteria for
Buildings and Next Steps. European Commission Joint Research Centre, Institute for
Prospective Technological Studies: Seville, Spain.
DOC (2006). Concepts and Methods of the U.S. I-O Accounts. U.S. Department of Commerce,
Bureau of Economic Analysis: Washington, DC.
DOC (2009). 2005-2009 American Community Survey (ACS), Table S2504, Physical Housing
Characteristics for Occupied Housing Units. U.S. Department of Commerce, Census Bureau:
Washington, DC.
DOC (2010a). 2010 Characteristics of New Housing. U.S. Department of Commerce:
Washington, DC. Retrieved June 7,2011 from
http: //www. census. gov/const/C25 Ann/c25 ann2010. pdf
DOC (2010b). Commodity-by-Industry Direct Requirements, after Redefinitions (1987, 1992,
1997 to 2009). U.S. Department of Commerce, Bureau of Economic Analysis: Washington,
DC.
DOE (2009). Emissions of Greenhouse Gases in the United States 2008. U.S. Department of
Energy, Energy Information Agency: Washington, DC.
DOE (2011 a). 2010 Buildings Energy Data Book. U.S. Department of Energy, Building
Technologies Program: Washington, DC. March.
DOE (20 lib). Annual Energy Outlook 2011. U S. Department of Energy, Energy Information
Agency: Washington, DC.
EPA (1993). EPA Office of Compliance Sector Notebook Project, Profile of Stone, Clay< Glass,
and Concrete Products Industry. U.S. Environmental Protection Agency, Office of
Enforcement and Compliance Assurance. EPA/310-R-95-017: Washington, DC.
EPA (2000). Toward Integrated Environmental Decision-Making. U.S. Environmental Protection
Agency, Science Advisory Board. EPA-SAB-EC-00-011: Washington, DC.
EPA (2003a). Estimating 2003 Building-related Construction and Demolition Materials
Amounts. U.S. Environmental Protection Agency: Washington, DC.
EPA (2003b). Economic Impact Analysis for the Brick and Structural Clay Products
Manufacturing NESHAP: Final Rule. U.S. Environmental Protection Agency, Office of Air
Quality Planning and Standards. EPA-452/R-03-006: Research Triangle Park, NC.
EPA (2006). Life Cycle Assessment: Principles and Practice. U.S. Environmental Protection
Agency. National Risk Management Research Laboratory. EPA/600/R-06/060: Cincinnati,
OH.
87
-------
EPA (2009). Sustainable Materials Management: The Road Ahead. U. S. Environmental
Protection Agency. EPA530-R-09-009: Washington, DC. June.
EPA (2011). Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2009. U.S.
Environmental Protection Agency. EPA 430-R-l 1-005: Washington, DC.
Gao, W. Ariyama, T., Ojima, T., Meier, A. (2001) Energy impacts of recycling disassembly
material in residential buildings. Energy and Buildings 33, 553-562.
Guinee, J.B., Gorree, M., Heijungs, R., Huppes, G, Kleijn, R., Koning, A de, Oers, L. van,
Wegener Sleeswijk, A., Suh, S., Udo de Haes, H.A., Bruijn, H. de, Duin, R. van, and
Huijbregts, M.A.J. (2002) Handbook on life cycle assessment, Operational guide to the ISO
standards. Kluwer Academic Publishers: Dordrecht, Netherlands.
Harvard University (2009). The Remodeling Market in Transition, Improving America's Housing
2009. Harvard University Center for Housing Studies: Cambridge, MA.
Heijungs, R. and S. Suh (2002). The Computational Structure of Life Cycle Assessment. Kluwer
Academic Publishers: Dordrecht, Netherlands.
Hendrickson, C.T., L.B. Lave and H.S. Matthews (2006). Environmental Life Cycle Assessment
of Goods and Services: An Input-Output Approach. Resources for the Future Press:
Washington, DC.
IPCC (2001). Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the
Third Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge
University Press: Cambridge, UK and New York, NY, USA
ISO (1997). Environmental management - life cycle assessment - principles and framework.
International Organization for Standardization (ISO): Geneva, Switzerland.
Joshi. S. (1999). Product Environmental Life-Cycle Assessment using input-output techniques. J
IndEcol 1999; 3(2-3): 95-120.
Lave L, F. E. Cobas, C. Hendrickson and F. McMichael F. (1995). Using input-output analysis to
estimate economy wide discharges. Environ Sci Technol 1995;29(9):420-6.
Lenzen M. (2001). Errors in conventional and input-output-based Life Cycle Inventories. J Ind
Ecol 2001;4(4): 127-48.
NAHB (\999).The Truth About Regulatory Barriers to Housing Affordability. National
Association of Homebuilders: Washington, DC.
NAHB (2004). Housing Facts, Figures and Trends 2004. National Association of Homebuilders:
Washington, DC.
O'Connor, J. (2004). Survey on actual service lives for North American buildings. Woodframe
Housing Durability and Disaster Issues Conference, Las Vegas, October. Retrieved July 1,
2011 from http://www.softwoodlumber.org/pdfs/SurveyonActualServiceLives.pdf
OECD (2005). Outcome of the First OECD Workshop on Sustainable Materials Management,
Report to the Working Group on Waste Prevention and Recycling. Organisation for
Economic Cooperation and Development. ENV/EPOC/WGWPR/RD(2005)5/FINAL: Paris.
88
-------
Oregon DEQ (2010). A Life Cycle Approach to Prioritizing Methods of Preventing Waste from
the Residential Construction Sector in the State of Oregon. Department of Environmental
Quality, Report No. 10-LQ-22: Portland, OR. September.
Ramesh T., R. Prakash and K.K. Shukla (2010). Life cycle energy analysis of buildings: an
overview. Energy and Buildings 42 (2010), 1592-1600.
RIVM(1997). USES 2.0, The Uniform System for the Evaluation of Substances, version 2.0: The
Netherlands Supplement to EUSES. Report No. 679102-037. National Institute for Public
Health and the Environment (Rijksinstituut voor Volkegezondheid en Milieu), Bilthoven, The
Netherlands.
Sara, B., E. Antonini and M. Tarantini (2001). Application of life cycle assessment (LCA)
methodology for valorization of building demolition materials and products. Proceedings of
SPIE, Environmentally Conscious Manufacturing, 6-8 November 2000, Boston.
Suh, S. and G. Huppes (2002). Missing inventory estimation tool using extended input-output
analysis. IntJLCA 2002;7(3): 134-40.
Suh, S. (2004). CEDA 3.0 User's Guide. Leiden University Institute for Environmental Science:
Leiden, Netherlands.
Suh, S., M. Lenzen, G.J. Treloar, H. Hondo, A. Horvath, G. Huppes, O. Jolliet, U. Klann, W.
Krewitt, Y. Moriguchi, J. Munksgaard and G. Norris (2004). System boundary selection in
life cycle inventories using hybrid approaches. Environ. Sci. Technol. 39 (3), pp. 657-664.
Suh, S. and G. Huppes (2005): Methods in Life Cycle Inventory (LCI) of a product, Journal of
Cleaner Production, 13 (7), 687 - 697.
USGS (1998). Estimated Use of Water in the United States in 1995. U.S. Department of the
Interior, U.S. Geologic Survey. Circular 1200. Washington, DC.
USGS (2011). Toxic Substances Hydrology Program Research Project: Cotton Agriculture-
Southern United States. Retrieved September 20, 2011 from
http://toxics.usgs.gov/regional/cotton.html.
WRI (2008). Material Flows in the United States, A Physical Accounting of the U.S. Industrial
Economy. World Resources Institute, Washington, DC
89
-------
APPENDICES
-------
APPENDIX A - SINGLE-FAMILY HOME CONSTRUCTION AND
RENOVATION DATA
Appendix A1 - Mass and Cost of Replacement Materials/Products during the Occupancy
Phase of a Single-Family Home
Appendix A2 - Remodeling expenditures in the US in 1998-1999
Appendix A3 - Specification of Average Residential Building for Occupancy-Phase
Analysis
A-l
-------
APPENDIX Al - MASS AND COST OF REPLACEMENT MATERIALS/PRODUCTS DURING THE OCCUPANCY PHASE
OF A SINGLE-FAMILY HOME
Carpeting
Linoleum flooring
Roofing (asphalt shingle)
Insulation (glass fiber)(a)
Drywall(b)
Doors/Windows(c)
Plasticsld)
Lumberle)
Hardware^
Electrical1^
Foundation
Paints
Siding (wood shingle)
Otherw
Total
Mass (kg)
Replacement Mass
(kg)(1)
3,300.00
270
8,170.00
1,830.00
7,710.00
2,310.00
488
9,390.00
286
84
-
393
6,360.00
2,750.00
43,300.00
Monetization
Replacement in USD
per 1 standard
residential home(2)
65,476.19
2,534.13
10,235.24
3,816.88
2,731.45
12,043.12
8,396.10
13,268.74
7,865.00
6,619.20
-
715.39
12,720.00
32,950.86
179,372.32
Total in
million USD(3)
5,222.03(5)
2,939.59
11,872.88
4,427.58
3,168.48
13,970.02
9,739.48
15,391.74
9,123.40
7,678.27
-
829.86
14,755.20
38,223.00
208,071.89
Cross-check with the Harvard University study
Corresponding/related item
(may duplicate)
Flooring/Paneling/Ceiling
Flooring/Paneling/Ceiling
Roofing
Insulation
N/A
Window/door
N/A
N/A
N/A
Electrical system
N/A
N/A
Siding
Other
Total in million USD(4)
12,334.94
12,334.94
11,486.02
901.29
-
7,192.50
-
-
-
1,353.67
-
-
6,039.70
19,247.16
121,804.08
^Replacement weights from Oregon DEQ (2010), Table 9 (p. 59)
<2) Replacement weights monetized based on Oregon DEQ (2010), Appendix 8, Cost per unit data ($2010)
(3) Assuming 1.16 million homes built in 1998 (DOE 2011, Table 2.5.1)
(4) Assuming the same annual replacement expenditure will occur over the 51.6 years of average life-time for 1.16% of the homes exist in 1998-1999, where 1.16% is derived from DOE (201 la), Tables
2.2. land 2.5.1
<5) Adjusted based on 1998 IO table
Basis for unit cost assumptions:
(a) Assumed to be R25 fiberglass insulation
(b) Assumed to be 5/8-inch gypsum board
(c) Based on higher unit cost data included for "windows" in Oregon DEQ (2010), Appendix 8
(tl) Based on highest unit cost data included in Oregon DEQ (2010), Appendix 8, for items that could be categorized as "plastics" (i.e., "PVC film" unit cost used)
(e) Assumed to be 4x12 lumber
® Based on highest unit cost data included in Oregon DEQ (2010), Appendix 8, for items that could be categorized as "hardware" (i.e., "faucet" unit cost used)
® Based on highest unit cost data included in Oregon DEQ (2010), Appendix 8, for items that could be categorized as "electrical" (i.e., "electrical boxes" unit cost used)
w The average price of all items included in Oregon DEQ (2010), Appendix 8, used as basis for unit price for this category.
A-2
-------
APPENDIX A2 - REMODELING EXPENDITURES IN THE US IN 1998-1999
(Harvard University report)
Base year 1998-1999; over 1 year, total
residential building
Kitchen
Bath
Other
Replacement
Exterior
Total
Minor remodeling
Major remodeling
Additions/Alterations
Minor remodeling
Major remodeling
Additions/Alterations
Bedroom
Other room
Deck/Porch
Other interior
Disaster repairs
Roofing
Siding
Plumbing
Electrical system
Window/door
Plumbing fixtures
Insulation
Flooring/Paneling/Ceiling
HVAC
Appliances
Garage
Other
Million USD total
expenditure
$ 7,595.00
$ 9,841.00
$ 1,376.00
$ 4,646.00
$ 6,036.00
$ 3,890.00
$ 13,044.00
$ 20,618.00
$ 5,620.00
$ 3,203.00
$ 7,693.00
$ 19,957.00
$ 10,494.00
$ 1,588.00
$ 2,352.00
$ 12,497.00
$ 2,938.00
$ 1,566.00
$ 21,432.00
$ 14,487.00
$ 4,507.00
$ 2,813.00
$ 33,442.00
$211,635.00
Excerpted from: http://www.jchs.harvard.edu/publications/remodeling/remodeling_2003.pdf
A-3
-------
APPENDIX A3 - SPECIFICATION OF AVERAGE RESIDENTIAL BUILDING FOR
OCCUPANCY-PHASE ANALYSIS
• Base year: c.a. 1998
• Average size: 2,170sf
• Total units built: 1,160,000
• Total cost: 184 billion USD (in 1998$)
• Expected longevity: 51.6 year
• Average physical material input to the single unit residential construction
- 13,837 board-feet of lumber
- 13,118 square feet of sheathing
- 19 tons of concrete
- 3,206 square feet of exterior siding material
- 3,103 square feet of roofing material
- 3,061 square feet of insulation
- 6,050 square feet of interior wall material
- 2,335 square feet of interior ceiling material
- 226 linear feet of ducting
- 19 windows
- 4 exterior doors (3 hinged, 1 sliding)
- 2,269 square feet of flooring material
- 12 interior doors
- 6 closet doors
- 2 garage doors
- 1 fireplace
- 3 toilets, 2 bathtubs, 1 shower stall
- 3 bathroom sinks
- 15 kitchen cabinets, 5 other cabinets
- 1 kitchen sink
- 1 range, 1 refrigerator, 1 dishwasher, 1 garbage disposal, 1 range hood
- 1 washer, 1 dryer
- 1 heating and cooling system
Source: NAHB (2004)
A-4
-------
APPENDIX B - INPUT-OUTPUT LIFE CYCLE IMPACT ANALYSIS
DEFINITIONS
Appendix B1 - Impact Categories and Definitions
Appendix B2 - Definition of Direct and Indirect Impacts Appendix B
B-l
-------
APPENDIX Bl - DEFINITIONS OF IMPACT CATEGORIES
Abiotic Depletion Potential:
Acronym: ADP
Units: kg antimony equivalent (kg Sn-eq.)
Definition: Abiotic resources are natural resources, such as iron ore, crude oil, and wind energy,
which are regarded as non-living. For the purposes of this analysis, abiotic depletion potential is
defined in terms of the annual rate of depletion of the stock of minerals and fossil fuels relative to
ultimate reserves.
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.1 (pp. 56-57)
Land Use Competition:
Acronym: LUC
Units: m2*yr
Definition: Loss of land as a resource, in the sense of being temporarily unavailable for other uses,
due to human use.
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.3 (pp. 57-59)
Global Warming Potential:
Acronym: GWP
Units: kg carbon dioxide equivalent (kg CO2-eq.)
Definition: Impact of human emissions on the radiative forcing (see glossary of terms) of the
atmosphere, characterized using the model developed by the Intergovernmental Panel on Climate
Change (IPCC), which defines the GWP of different greenhouse gases. Based on a 100-year time
horizon (i.e., GWP100).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.5 (pp. 59-60)
Stratospheric Ozone Depletion Potential:
Acronym: OOP
Units: kg CFC-11 equivalent (kg CFC-11-eq.)
Definition: Impact of anthropogenic emissions on the thinning of the stratospheric ozone layer,
resulting in a greater fraction of solar UV-B radiation reaching the earth's surface, characterized
using the model developed by the World Meteorological Organisation, which defines the ozone
depletion potential of different gases. Based on an infinite time horizon (i.e., ODP«).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.6 (pp. 60-61)
B-2
-------
Human Toxicity Potential:
Acronym: HTP
Units: kg 1,4-dichlorobenzene equivalent (kg p-DCB-eq.)
Definition: Impact on human health of toxic substances present in the environment (i.e., excluding
workplace exposures), characterized based on USES 2.0 (PJVM, 1997), describing fate, exposure,
and effects of toxic substances, adapted to LCA. Based on an infinite time horizon (i.e., HTP«).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.7 (p. 61)
Freshwater Aquatic Ecotoxicity Potential:
Acronym: FAETP
Units: kg 1,4-dichlorobenzene equivalent (kg p-DCB-eq.)
Definition: Impact of toxic substances on freshwater aquatic ecosystems, characterized based on
USES 2.0 (PJVM, 1997), describing fate, exposure, and effects of toxic substances, adapted to
LCA. Based on an infinite time horizon (i.e., FAETP«).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.8.1 (p. 62)
Marine Aquatic Ecotoxicity Potential:
Acronym: MAETP
Units: mton 1,4-dichlorobenzene equivalent (mton p-DCB-eq.)
Definition: Impact of toxic substances on marine aquatic ecosystems, characterized based on USES
2.0 (PJVM, 1997), describing fate, exposure, and effects of toxic substances, adapted to LCA.
Based on an infinite time horizon (i.e., MAETP „).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.8.2 (pp. 62-63)
Terrestrial Ecotoxicity Potential:
Acronym: TETP
Units: kg 1,4-dichlorobenzene equivalent (kg p-DCB-eq.)
Definition: Impact of toxic substances on terrestrial ecosystems, characterized based on USES 2.0
(PJVM, 1997), describing fate, exposure, and effects of toxic substances, adapted to LCA. Based
on an infinite time horizon (i.e., TETP«).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.8.3 (p. 63)
B-3
-------
Freshwater Sediment Ecotoxicity Potential:
Acronym: FSETP
Units: mton 1,4-dichlorobenzene equivalent (mton p-DCB-eq.)
Definition: Impact of toxic substances on the sediment of freshwater aquatic ecosystems,
characterized based on USES 2.0 (PJVM, 1997), describing fate, exposure, and effects of toxic
substances, adapted to LCA. Based on an infinite time horizon (i.e., FSETP „).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.8.4 (pp. 63-64)
Marine Sediment Ecotoxicity Potential:
Acronym: MSETP
Units: kg 1,4-dichlorobenzene equivalent (kg p-DCB-eq.)
Definition: Impact of toxic substances on the sediment of marine aquatic ecosystems, characterized
based on USES 2.0 (PJVM, 1997), describing fate, exposure, and effects of toxic substances,
adapted to LCA. Based on an infinite time horizon (i.e., MSETP «).
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.8.5 (p. 64)
Photochemical Ozone Creation Potential:
Acronym: POCP
Units: kg ethylene equivalent (kg C4H4-eq.)
Definition: Impact of human emissions of volatile organic compounds (VOCs) and carbon
monoxide (CO) in the presence of nitrogen oxides (NOX) resulting in the formation of reactive
chemical compounds, including ozone, by the action of sunlight, characterized based on the United
Nations Economic Commission for Europe (UNECE) Trajectory model.
Reference: Baseline definition ("high NOX POCP") from Guinee et al. (2002), Part 2A, Section
4.3.3.9 (p. 65)
Acidification Potential:
Acronym: AP
Units: kg sulfur dioxide equivalent (kg SO2-eq.)
Definition: Impact of human emissions of acidifying substances (e.g., SO2, NOX, NHX) on soil
groundwater, surface waters, biological organisms, ecosystems, and built infrastructure,
characterized based on the International Institute for Applied Systems Analysis (IIASA) RAINS 10
model, describing the fate and deposition of acidifying substances, adapted to LCA.
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.10 (pp. 65-66)
B-4
-------
Eutrophication Potential:
Acronym: EP
Units: kg phosphate equivalent (kg PO4-eq.)
Definition: Impact of high environmental levels of macronutrients, the most important of which are
nitrogen (N) and phosphorus (P), in terms of excessive nutrient enrichment and shifts in species
composition and elevated biomass production in aquatic and terrestrial ecosystems, characterized
based on the stoichiometric procedure applied to aquatic and terrestrial systems.
Reference: Baseline definition from Guinee et al. (2002), Part 2A, Section 4.3.3.11 (p. 66)
Energy Consumption:
Acronym: EC
Units: million BTUs
Definition: Total net primary energy consumption, including consumption of fossil fuels, nuclear
energy, and renewable energy (not including geothermal energy), based on sector data provided by
the Energy Information Agency (EIA). For fossil fuels, energy consumption is allocated to the
point of combustion. For renewable and nuclear energy, energy consumption is allocated to the
power-generating facility.
Reference: Equivalent to "energy use" as defined in EPA (2009), Appendix: Relative Ranking
Technical Support Document (pp. 16-17)
Water Consumption:
Acronym: WC
Units: thousand gallons
Definition: Total water used by operation or facility, including: for agriculture, total water used in
irrigation; for commercial/industrial sectors, net intake plus water re-circulated; and for electricity
generation, total water used in thermoelectric (in-stream and off-stream) and hydropower facilities
(in-stream), as defined by USGS (1998).
Reference: Equivalent to "water use" as defined in EPA (2009), Appendix: Relative Ranking
Technical Support Document (pp. 12-15)
B-5
-------
Material Input:
Acronym: MTL
Units: thousand kg or metric ton (mton)
Definition: Raw materials required to produce a commodity, including domestically extracted
and imported raw materials, less processing wastes and exports of processed materials,
consistent with the World Resources Institute (WRI) definition of direct material consumption
(DMC) (WRI 2008).
Reference: Equivalent to "material use" as defined in EPA (2009), Appendix: Relative Ranking
Technical Support Document (pp. 9-12)
Waste:
Acronym: WST
Units: thousand kg or metric ton (mton)
Definition: Materials that are consumed in the U.S. economy and exit (e.g., through disposal in
a landfill) within 30 years after entry, consistent with the World Resources Institute (WRI)
definition of direct process output (DPO) (WRI 2008).
Reference: Equivalent to "material waste" as defined in EPA (2009), Appendix: Relative Ranking
Technical Support Document (p. 12)
-------
APPENDIX B2- "DIRECT" AND "INDIRECT" IMPACTS
Input contribution analysis of, for example, the pre-occupancy phase of a single-family home includes
impact estimates and resource withdrawals associated with each of the materials and products delivered to
the job site and each of the services provided in support of the home construction. Input contribution
analysis of the occupancy phase includes impacts estimates and resource withdrawals associated with
living in the home and operating appliances and other systems, as well as the impacts and resource
withdrawals associated with replacement materials and products. Output contribution analysis
disaggregates these impacts and resource withdrawals to their original source in the supply chain.
The I-O LCA described herein labels impacts and resource withdrawals that take place during
construction or directly in the use of the home as "direct" impacts or resource withdrawals. Impacts and
resource withdrawals associated with upstream supply chain processes are labeled "indirect." Figures 2-3
and 2-4 illustrate these distinctions for the pre-occupancy and occupancy phases of a single-family home,
respectively.
Figure B-l
Direct and Indirect Impacts and Resource Withdrawals Associated with Single-family Home
Construction
Upstream Supply Chain
Processes
Direct Inputs
Raw materials
Manufacturing
Energy
Water
Services
Transportation
Raw materials used in
construction
Manufactured
products
Electricity
Fuel
Water
Construction and
support services
Machinery
I
I
Emissions to air, water, and land (including waste) and
water and materials consumed, and fuel combusted during
manufacturing and delivery of materials, products, and
services to job site
+ * *
Indirect Environ mental Impacts and Resource
Withdrawals
Impacts of emissions on environmental conditionsand
human and ecological receptors and quantities of resources
withdrawn/used
\
Direct Resource
Withdrawals
Amount of
material, fuel,
and water
consumed;1
combusted
during home
construction
I
!
Emissions to air, water, and
land (including waste)
generated during home
construction
+
Direct Environmental Impacts
Impacts of emissions on
environmental conditions and
human and ecological receptors
B-7
-------
Figure B-2
Direct and Indirect Impacts and Resource Withdrawals Associated with Single-family Home
Occupancy
Upstream Supply Chain
Processes
Direct Inputs
Raw materials
Manufacturing
Energy
Water
Services
Transportation
1
k
\
r Productsand ^
materials replaced
during home
^ occupancy _,
Electricity
Fuel
Water
Renovation and
support services
Machinery
)
Emissions to air, water, and land (including waste) and
water and materials consumed, and fuel combusted during
manufacturing and delivery of materials, products, and
services to the home
* 1 *
Indirect Environmental Impacts and Resource
Withdrawals
Impacts of emissions on environmental conditions and
human and ecological receptors and quantities of resources
withdrawn/used
Direct Resource
Withdrawals
Amount of material,
fuel, and water
consumed/combuste
d while living in the
home (e.g., to
operate appliances)
and during home
renovation
Emissions to air, water, and
land (including waste)
generated during home
occupancy
*
Direct Environmental Impacts
Impacts of emissions on
environmental conditions and
human and ecological receptors
These figures illustrate the following concepts:
Distinction between Environmental Impacts and Resource Withdrawals
The I-O LCA for single-family homes includes 17 "impact" categories. These include categories that
express estimates of emissions to air, water, and land in terms of their environmental, human health, and
ecological impacts and in terms of the withdrawal of natural resources from the environment. Table B-l
summarizes how the impact categories are grouped for this analysis. Note that some categories classified
as "environmental impacts" could also be considered "resource withdrawals" (e.g., abiotic depletion).
The distinction between environmental impacts and resource withdrawals is conceptual and does not
affect the findings and conclusions of the I-O LCA.
Note that the consumption of some materials, products, and services represents both a resource
withdrawal and an environmental impact, as those terms are defined herein. For example, water
consumed during home construction to establish a new lawn would be accounted for in the water
consumption (WC) factor. It represents a demand on this resource in terms of an out-of-stream use.
-------
Depending on factors such as fertilizer application, erosion controls, and other hydrologic factors (e.g.,
ground water-surface water interaction in the area), this water use could also result in run-off
("emissions") of nutrients to nearby surface water, which could affect the nutrient balance and would be
accounted for in the eutrophication potential (EP) impact category.
The distinction between environmental impacts and resource withdrawals is represented in Figures B-l
and B-2. Using the example above, water consumed during construction is shown on Figure B-l as a
brown arrow from the direct input "Water" to the "Direct Resource Withdrawals" text box. The impacts
associated with the water use (impacts from run-off associated with establishing a lawn) occur through a
more complex pathway, involving emissions and consequent changes to the environmental condition of
the nearby waterbody. This is represented by the two text boxes under the home graphic, where the first
represents the emissions (runoff) and the second, labeled "Direct Impacts," represents the environmental
effects of this emissions.
From the standpoint of the LCA model, water consumption data are derived directly from reported data
whereas eutrophication potential (EP) estimates are derived from both emissions data and a
characterization model (see Appendix B-l for a description of data and methods). These two pathways
are not redundant. Rather, they represent two different types of impacts (in a broad sense) in which the
water consumed during home construction can affect the environment. Similar concepts apply to energy
consumption, material input, etc.
Table B-l
Classification of Impact Categories for LCA of Single-Family Homes
Environmental Impact Categories
Resource Withdrawal Categories
Abiotic depletion potential (ADP)
Global warming potential (GWP)
Stratospheric ozone depletion potential (ODP)
Human toxicity potential (HTP)
Freshwater aquatic ecotoxicity potential (FAETP)
Marine aquatic ecotoxicity potential (MAETP)
Terrestrial ecotoxicity potential (TETP)
Freshwater sediment toxicity potential (FSETP)
Marine sediment toxicity potential (MSETP)
Photochemical ozone creation potential (POCP)
Acidification potential (AP)
Eutrophication potential (EP)
Waste (WST)
Land use competition (LUC)
Energy consumption (EC)
Water consumption (WC)
Material input (MTL)
Distinction between Direct and Indirect Impacts
From the perspective of the single-family home, direct impacts include those environmental impacts and
resource withdrawals that occur over the life cycle of a single family home. For the pre-occupancy phase,
these include, for example, impacts associated with emissions from construction vehicles, impacts
associated with run-off from the job site, etc. Direct resource withdrawals during the pre-occupancy
phase include materials, fuel, and water consumed during the construction of the home. For the
B-9
-------
occupancy phase, direct impacts include impacts associated with emissions generated by the operation of
appliances and the care and maintenance of the home. Direct resource withdrawals during the occupancy
phase include material inputs associated with replacements and fuel consumed in appliances, water used
for bathing and laundry, etc. Direct impacts associated with the post-occupancy phase would include
impacts associated with emissions from demolition equipment, water consumed during
demolition/deconstruction, waste generated, etc.
Indirect impacts include environmental impacts and resource withdrawals associated with the production
and/or delivery of the direct inputs required over the life cycle of the home. These include impacts
associated with emissions generated during the manufacturing of products used to build or renovate the
home, including embodied impacts associated with upstream supply chain processes. They also include
resource withdrawals required to produce direct inputs (e.g., energy consumed), including resource
withdrawals associated with all upstream supply chain processes.
Allocation of Energy Consumption and Energy-Associated Impacts
Energy consumption and associated impacts associated with the life cycle of a home are allocated to the
point at which the fuel used to produce the energy is combusted (or, in the case of hyroelectric power, the
point at which water is used). Fuel that is combusted in construction vehicles during the construction or
renovation of a home, is considered a direct resource withdrawal and impacts associated with the vehicle
emissions are considered direct impacts. Likewise, energy consumed by a gas stove or water heater in the
home is considered a direct resource withdrawal.
Resources withdrawn and impacts associated with electricity used in home construction, occupancy, or
demolition/deconstruction are considered indirect impacts. For example, coal used to produce electricity
is combusted at the power plant and, thus, is allocated to the upstream supply chain associated with
electric services. Likewise, energy consumed in the extraction of materials, manufacturing of products
and equipment, etc. used in the life cycle of a single family home is considered an indirect resource
withdrawal and associated impacts are considered indirect impacts.
B-10
-------
APPENDIX C - VECTOR ANALYSIS METHODOLOGY
Background
Vector analysis, or spatial vector analysis, is a technique used to support multi-factor decision-making.
Vector analysis involves analyzing the interactions between two or more variables by plotting measures
of the variables in a graphical representation of the decision space. The resulting vector includes both
measures of magnitude and direction. For the contribution analyses described in this report, vector
analysis was used to derive:
• Vector magnitude, representing the extent to which the impacts associated with a material,
product, or service differ from those associated with the rest of the materials, products, and
services being considered.
• Change in vector orientation, describing the strength of influence of one impact category relative
to all other impact categories being analyzed for a specific material, product, or service.
This approach was developed for the 2020 Vision Relative Ranking Analysis as a way to rank materials,
products, and services across multiple impact criteria without weighting criteria and in a way that showed
the influence of different criteria on the overall ranking. The vector magnitude calculated using this
methodology does not represent an estimate of actual impact but, rather, they indicate the degree to which
the material, product, or service is an "outlier," or how much it deviates from the mean relative to all
materials, products, and services being measured. The change in vector orientation is an indicator of the
criterion/criteria that has/have the greatest effect on magnitude.
Method
Upon completion of the contribution analyses based on individual environmental impact categories, the
vector analysis was used to rank materials, products, and services across all impact categories and across
the impact categories considered in the three impact subgroupings (i.e., natural resources and land use,
toxicity, and pollution impacts). Specifically, the following steps were employed:
• Step 1 - Compile CEDA data: CEDA output data were compiled for each of the supply chain
processes, materials, products, and services and for each impact category. Supply chain
processes, materials, products, and services that did not indicate contribution to life cycle impacts
associated with the pre-occupancy phase of single-family homes were eliminated from the
analysis.
• Step 2 - Calculate measure of variance: The average (mean value) for each criterion was
computed and subtracted from the criterion value for each of the supply chain processes,
materials, products, and services retained in the analysis, the standard deviation for each impact
category was calculated, and the mean-centered values were normalized by the standard
deviation.
• Step 3 - Calculate vector magnitude: Vector magnitudes were calculated by "plotting" standard
deviations on different axes corresponding to each of the different impact categories, vector
C-l
-------
magnitudes were calculated as the basis for ranking supply chain processes, materials, products
and services.
• Step 4 - Calculate criterion-specific change in vector orientation: To analyze individual impact
categories' contributions to the overall ranking of a specific supply chain process, material,
product, or service, the change in vector orientation associated with adding the standard deviation
measure for a specific impact category to the vector plotted without the category was calculated.
Example
The following discussion uses the analysis of the relative ranking of ready-mixed concrete and mineral
wool within the pollution impact grouping based on input contribution analysis of the pre-occupancy
phase to illustrate the vector analysis methodology.
Step 1 - Compile CEDA data
Table C-l shows the results of the input contribution analysis for the pre-occupancy phase for the criteria
included in the pollution impact grouping:
Table C-l
CEDA Output for Ready-Mixed Concrete and Pollution Impact Categories
Input Contribution Analysis, Pre-Occupancy Phase
Material/product/service
Ready-mixed concrete
Mineral wool (including
fiberglass and mineral wool
insulation)
All other materials, products, and
services identified as direct
inputs to single-family homes,
pre-occupancy phase
Impact
# SD from the mean
Impact
#SD from the mean
Sum of impacts
Mean impact estimate
Standard deviation of impact estimates
Impact Categories in Pollution Impacts Grouping
GWP
kg C02 eq.
1.01x104
7.96
4.13x103
2.94
8.47x1 05
6.08x102
1.20x103
OOP
kg CFC-1 1 eq.
1.00x10-2
0.39
2.26x1 0-1
13.30
2.02x10°
3.50x10-3
1.68x10-2
POCP
kg C4H4 eq.
4.97x10°
6.54
2.21x10°
2.62
3.87x102
3.55x1 0-1
7.06x1 0-1
AP
kg S02 eq.
5.15x101
8.62
1.24x101
1.72
5.51x103
2.59x10°
5.67x10°
EP
kg P04 eq.
5.28x10°
8.09
1.44x10°
1.86
3.56x102
2.95x1 0-1
6.16x10-1
Step 2 - Calculate measure of variance
The measure of variance—number of standard deviations from the mean—is calculated for each impact
category and each material, product, and service by subtracting the impact estimate for the specific
material, product, or service from the mean for all materials, products, and services and dividing the result
by the standard deviation. Table C-l shows this calculation for ready-mixed concrete and mineral wool.
C-2
-------
Step 3 - Calculate vector magnitude
Vector magnitudes and direction were calculated by "plotting" the number of standard deviation from the
mean on different axes, each corresponding to a different impact category. Figure C-l depicts how the
vector magnitude and direction were calculated for the first two impact categories (GWP and ODP) for
ready-mixed concrete and mineral wool.
Figure C-l
Vector Magnitude and Direction Plotted in 2 Dimensions (GWP and ODP)
ODP
JGWP,ODP
Mineral wool:
VMGWp,ODP=(2.942+13.302)1/2= 13.62
= tan (13.30/2.94)= 77.5°
Ready-mixed concrete:
VMGWp,ODP=(7.962+0.392)1/2= 7.96
QGWP.ODP = tan"1(0.39/7.96)= 2.8°
GWP
Figure C-l illustrates two examples of how the vector magnitude and direction can provide information
used for ranking materials, products and services on two dimensions and understanding the key driving
factors behind the rankings. In this example, mineral wool would be ranked relatively higher than ready-
mixed concrete when considering the two impact categories, GWP and ODP (the vector magnitude for
mineral wool of 13.62 is higher than that for ready-mixed concrete, 7.96).
The orientation of the two vectors indicate that the vector magnitude associated with ready-mixed
concrete is primarily a function of the relatively high GWP impact embodied in ready-mixed concrete
when compared to other direct inputs to a single-family home. The orientation of the vector for mineral
wool indicates that ODP impacts are the driving factor behind its relatively high ranking.
Further review indicates that mineral wool is ranked relatively higher than ready-mixed concrete on these
two dimensions because of the relatively greater extent to which the ODP impacts associated with
mineral wool differ from the average as compared to the extent to which the GWP impacts associated
with ready-mixed concrete differ from the average.
-------
The above analysis can be expanded to a third impact category by plotting the vector magnitude and
direction in a third, orthogonal dimension. Additional impact categories can be included by plotting the
vectors in additional, orthogonal dimensions. As long as each additional dimension is orthogonal, the
basic calculus for vector magnitude in two dimensions can be projected to the number of dimensions
(impact categories) of interest. The generalized equation for calculating vector magnitudes is as follows:
For ready-mixed concrete and mineral wool, the vector magnitudes calculated based on the pollution
impacts grouping were calculated as follows:
Ready-mixed concrete: VMpoll = (7.962+0.392+6.542+8.622+8.092)'/2 = 15.69
Mineral wool: VMpoll = (2.942+13.302+2.622+1.722+1.862)'/2 = 14.10
Step 4 - Calculate criterion-specific change in vector orientation
Ready-mixed concrete and mineral wool were the two most highly ranked product categories based on the
input contribution analysis for single-family homes and the pollution impacts grouping (see Figure 3-4 in
the main body of the report). A review of the vector magnitude calculations reveals that the relatively
high ranking associated with ready-mixed concrete reflects a combination of the relatively significant
impacts across several impact categories. By contrast, the vector magnitude calculated for mineral wool
is dominated by the ODP impact category (which accounts for 80% of the total vector magnitude).
To identify driving factors behind the relative rankings of materials, products and services, the change in
vector orientation associated with adding the standard deviation measure for a specific impact category to
the vector plotted without the category was calculated. Figure C-l shows this process in two dimensions,
where the effect of the ODP category in terms of the change in vector orientation using the equation:
=tan-l(#SDODp/#SD,
GWPJ
This approach can be projected into multiple dimensions by calculating the change in vector orientation
resulting when the standard deviation associated with a new factor is added to the vector representing the
combination of all other factors. Figure C-2 illustrates the approach for measuring the change in vector
orientation when the standard deviation measures for acidification potential (AP) are plotted relative to
the vector reflecting the combination of the other four impact categories associated with the pollution
impact grouping. Note that the X' axis represents the projection of the 4-dimensional vector calculated
based on GWP, ODP, POCP and EP impact categories onto a plane surface.
C-4
-------
Figure C-2
Change in Vector Orientation Resulting from Adding the AP Impact Category to All Other Impact
Categories in the Pollution Impact Grouping
AP
Ready-mixed concrete:
7.962+0.392+6
0X.,AP = tan"1(8.62/13.10)= 33.3
VMx.=(7.962+0.392+6.542+8.092)y° = 13.10
Mineral wool:
VMx.=(2.942+13.302+2.622+1.862)y'= 14.00
QGWP.ODP = tan'1(1.72/14.00)= 7.0°
X'=f(GWP,ODP,POCP,EP)
Review of the change in vector orientation indicates the AP impact category had a relatively strong effect
on the relative ranking of ready-mixed concrete based on the pollution impact grouping. The effect of the
AP category on the vector magnitude and relative ranking of mineral wool within this grouping was less
pronounced. This is consistent with the conclusions drawn by reviewing the vector magnitude
calculations. This approach was used to systematically analyze drivers behind relative rankings and is the
basis for the information presented in Tables 3-2 and 4-1 in the main body of the report.
Strengths and Weaknesses
The vector analysis supports the I-O LCA by compiling and presenting the I-O LCA results in a format
that is useful for subsequent policy analysis. Characteristics of the vector analysis approach are as
follows:
• The Vector analysis considers the impact characterization results for the full range of materials,
products and services that are either direct inputs to single family homes (input contribution
perspective) or are included in the supply chain (output contribution perspective). This system of
materials, products and services is not variable and thus, the vector analysis is not vulnerable to
the issue of rank reversal.
• The internal normalization used in the vector analysis is intended to highlight significance. To
fulfill its intended function, the vector analysis normalizes characterization results within an
C-5
-------
impact category in terms of number of standard deviations from the mean. From a descriptive
standpoint, this is preferable to more common methods currently used in LCA (e.g., division by
maximum or sum) in that it accounts for variability in the data.
• The vector analysis explicitly recognizes the theoretical and interpretational problems inherent in
summing non-commensurate units. To address this, the vector analysis combines internally
normalized results across impact categories using vector calculus and the assumption that the
measures of impact are orthogonal. While this is clearly a simplifying assumption, vector
addition is preferable to some of the more widely used compensatory methods in that it avoids the
intuitively problematic assumption that units measuring different types of impact can be directly
summed.
• As stated in the body of the report, the vector magnitude is descriptive and is not intended to
convey a measure of relative impact. Rather, it is intended to help inform subsequent policy
analysis and decision-making across a broad range of environmental policy contexts. The
approach recognizes the uncertainties inherent in the underlying data and characterization
methods and, as such, presents results in qualitative terms. Also, given its intended use, the
approach does not assume that a single weighting scheme will be applicable across all decision
contexts.
Primary sources of uncertainty in the single-family home analysis are the environmental and economic
data and the assumptions used in the characterization methodologies. To evaluate the potential effect of
uncertainty on the relative rankings obtained through the vector analysis, a perturbation analysis was
conducted on the results of the input contribution analysis, pre-occupancy phase. Categorized impacts
were randomly adjusted by ±5% and rankings were re-analyzed under different constraining conditions
(i.e., ±10%, ±20% and no constraint on overall change in impact in any one category). The results of the
analysis demonstrated that the vector analysis is robust at this level of potential random error, see Table
C-2 below.
In addition, because the vector magnitude across categories is calculated by summing vectors (which
squares the normalized result), the presence of materials, products and services that are significantly less
impactful than the mean for the system - as expressed by their negative normalized value, could in theory
increase the relative ranking of the material, product, service instead of lower it. A sensitivity analysis
was conducted to test the practical implications of this concern. Because the number of supply chain
processes associated with an material/product/service can vary (e.g., only 204 of the 480 materials,
products and services included in the BEA commodity categories were identified as direct inputs to the
pre-occupancy supply chain for single family homes), different sample sizes were analyzed. The
sensitivity analysis found that given the structure of the data in the I-O LCA model, the vector analysis
will consistently highlight the most impactful materials/products/services despite the theoretical
possibility that negative normalization results will incorrectly rank less impactful materials, products and
services more highly. As a practical matter, the vector analysis fulfills its intended function to help guide
policy analyses and decisions, see Table C-3 below.
C-6
-------
Table C-2
Analysis of Impact of Random Error on Relative Ranking Using Vector Analysis
Input Contribution Analysis, Pre-Occupancy Phase
Analysis of Impact of Random Error on Relative Ranking Using Vector Analysis
Analysis of Life Cycle Impacts Associated with Single Family Homes
Input Contribution Analysis, Pre-Occupancy Phase
January 7, 2013
Original Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Direct Input {Material/Product/Service)
Brick and structural clay tile
Ready-mixed concrete
Carpets and rugs
Mineral wool
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Trucking and courier services, except air
Reconstituted wood products
Sand and gravel
Motor vehicles and passenger car bodies
Sawmills and planing mills, general
Dimension, crushed and broken stone
Wholesale trade
Asphalt paving mixtures and blocks
Millwork
Paints and allied products
Cement, hydraulic
Cut stone and stone products
Electric services (utilities)
Converted paper products, n.e.c.
Refrigeration and heating equipment
Wood kitchen cabinets
Construction machinery and equipment
Metal doors, sash, frames, molding, and trim
Wood preserving
Petroleum refining
Sheet metal work
Gypsum products
Concrete block and brick
Wiring devices
Perturbation = +/- 5% of Characterized Impact
Within-lmpact Change <= 10%
Rank
1
2
3
4
5
6
8
7
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Change in Rank
0
0
0
0
0
0
-1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Within-lmpact Change <= 20%
Rank
1
2
4
3
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Change in Rank
0
0
-1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Unconstrained Change
Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
27
26
28
29
30
Change in Rank
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-1
1
0
0
0
Table C-3
Sensitivity Analysis of the Potential of the Vector Summation to Change the Relative Ranking of
Materials, Products or Services (MPS)
Number of MPS in Sample
300 MPS
200 MPS
Top 10 Ranked MPS
Percent of samples where top 10 remained in Top 10
Percent of cases where top 10 remained in Top 20
97%
100%
100%
100%
Top 20 Ranked MPS
Percent of cases where top 20 remained in Top 20
Percent of cases where top 20 remained in Top 30
97%
100%
90%
100%
Top 30 Ranked MPS
Percent of cases where top 30 remained in Top 30
Percent of cases where top 30 remained in Top 40
80%
100%
63%
90%
C-7
-------
APPENDIX D - OVERALL RESULTS SUMMARY
Life-Cycle Phase, Locus of
Impact
Pre-Occupancy Phase - Indirect
Pre-Occupancy Phase - Direct
Subtotal, Pre-Occupancy Phase
Occupancy Phase - Indirect
Occupancy Phase - Direct
Subtotal - Occupancy Phase
Post-Occupancy Phase - Indirect
Post-Occupancy Phase - Direct
Subtotal - Post-Occupancy Phase
Total
ADP
kg Sn eq.
499
0
499
4,651
0
4,651
0
0
0
5,150
LUC
m2*yr
11,002
0
11,002
14,199
10,403
24,602
0
0
0
35,604
GWP
kg C02 eq.
107,889
33,514
141,404
597,995
160,787
758,782
556
45
601
900,786
OOP
g CFC-11 eq.
617
0
617
1,138
0
1,138
0
0
0
1,755
HTP
kg p-DCB eq.
15,925
112
16,038
38,712
0
38,712
0
0
0
54,750
FAETP
kg p-DCB eq.
2,552
0
2,552
5,483
0
5,483
0
0
0
8,035
Life-Cycle Phase, Locus of
Impact
Pre-Occupancy Phase - Indirect
Pre-Occupancy Phase - Direct
Subtotal, Pre-Occupancy Phase
Occupancy Phase - Indirect
Occupancy Phase - Direct
Subtotal - Occupancy Phase
Post-Occupancy Phase - Indirect
Post-Occupancy Phase - Direct
Subtotal - Post-Occupancy Phase
Total
MAETP
mton p-DCB eq.
47,300
0
47,300
246,592
0
246,592
0
0
0
293,892
TETP
kg p-DCB eq.
3,137
0
3,137
6,252
0
6,252
0
0
0
9,389
FSETP
mton p-DCB eq.
17,124
0
17,124
83,748
0
83,748
0
0
0
100,872
MSETP
kg p-DCB eq.
29,924
0
29,924
41,601
0
41,601
0
0
0
71,525
POCD
kg C4H4 eq.
63
22
85
253
0
253
0
0
0
338
AP
kg S02 eq.
456
47
502
4,292
730
5,022
0
0
0
5,525
Life-Cycle Phase, Locus of
Impact
Pre-Occupancy Phase - Indirect
Pre-Occupancy Phase - Direct
Subtotal, Pre-Occupancy Phase
Occupancy Phase - Indirect
Occupancy Phase - Direct
Subtotal - Occupancy Phase
Post-Occupancy Phase - Indirect
Post-Occupancy Phase - Direct
Subtotal - Post-Occupancy Phase
EP
kg P04 eq.
54
12
66
247
0
247
0
0
0
EC
mBTU
1,084
133
1,216
7,899
5,885
13,783
0
20
20
we
103 gal
12,766
38
12,804
248,814
4,993
253,808
0
0
0
MTL
mton
1,101
1,568
2,669
1,006
43
1,050
0
0
0
WST
mton
118
0
118
580
43
623
0
52
52
D-l
-------
APPENDIX E - INPUT CONTRIBUTION ANALYSIS RESULTS
Appendix El - Pre-Occupancy-Phase Results by Impact Category
Appendix E2 - Vector Analysis Results, Input Contribution Basis, Pre-Occupancy Phase
Appendix E3 - Occupancy-Phase Results by Impact Category
E-l
-------
APPENDIX El - PRE-OCCUPANCY-PHASE RESULTS BY IMPACT CATEGORY
Abiotic Depletion Potential (ADP) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Asphalt paving mixtures and blocks
Ready-mixed concrete
Retail trade, except eating and drinking
Petroleum refining
Miscellaneous plastics products, n.e.c.
Reconstituted wood products
Wholesale trade
Mineral wool
Motor vehicles and passenger car bodies
Paints and allied products
Total Accounted for in Top 10 M/P/S
Total Life Cycle ADP impacts
Remainder
ADP
(kgSneq.)
39.15
24.46
23.50
21.32
21.07
18.66
17.34
16.22
15.59
12.87
210.19
498.78
288.59
Contribution to
Life Cycle ADP
7.85%
4.90%
4.71%
4.28%
4.22%
3.74%
3.48%
3.25%
3.13%
2.58%
42.14%
100.00%
57.86%
• Asphaft paving mixtures and
blocks
• Ready-mixed concrete
• Retail trade, except eating
and drinking
• Petroleum refining
• Miscellaneous plastics
products, n.e.c.
Reconstituted wood products
Wholesale trade
Mineral wool
Motor vehicles and passenger
car bodies
Paints and allied products
Remainder
Land Use Competition (LUC) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Sawmills and planing mills, general
Trucking and courier services, except air
Millwork
Wood preserving
Reconstituted wood products
Wood kitchen cabinets
Carpets and rugs
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Motor vehicles and passenger car bodies
Total Accounted for in Top 10 M/P/S
Total Life Cycle LUC impacts
Remainder
LUC
(m2*yr)
1,187.03
1,103.13
662.08
460.64
440.08
402.28
401.52
375.68
371.28
370.14
5,773.87
11,002.07
5,228.20
Contribution to
Life Cycle LUC
10.79%
10.03%
6.02%
4.19%
4.00%
3.66%
3.65%
3.41%
3.37%
3.36%
52.48%
100.00%
47.52%
• Sawmills and planing mills,
general
• Trucking and courier services,
except air
• Millwork
• Wood preserving
• Reconstituted wood products
Wood kitchen cabinets
Carpets and rugs
Miscellaneous plastics
products, n.e.c.
Retail trade, except eating and
drinking
Motor vehicles and passenger
car bodies
Remainder
E-2
-------
APPENDIX El (CONTINUED)
Global Warming Potential (GWP) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Ready-mixed concrete
Retail trade, except eating and drinking
Reconstituted wood products
Miscellaneous plastics products, n.e.c.
Trucking and courier services, except air
Motor vehicles and passenger car bodies
Cement, hydraulic
Mineral wool
Wholesale trade
Construction machinery and equipment
Total Accounted for in Top 10 M/P/S
Total Life Cycle GWP impacts
Remainder
GWP
(kgC02eq.)
11,549.88
5,864.40
5,182.87
5,029.22
5,027.66
4,784.99
4,783.80
4,706.06
4,251.64
3,387.25
54,567.77
141,403.66
86,835.88
Contribution to
Life Cycle GWP
8.17%
4.15%
3.67%
3.56%
3.56%
3.38%
3.38%
3.33%
3.01%
2.40%
38.59%
100.00%
61.41%
I Ready-mixed concrete
I Retail trade, except eating and
drinking
• Reconstituted wood products
I Miscellaneous plastics
products, n.e.c.
• Trucking and courier services,
except air
Motor vehicles and passenger
car bodies
Cement, hydraulic
Mineral wool
Wholesale trade
Construction machinery and
equipment
Remainder
Stratospheric Ozone Depletion Potential (OOP) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Mineral wool
Miscellaneous plastics products, n.e.c.
Cut stone and stone products
Paints and allied products
Metal doors, sash, frames, molding, and trim
Motor vehicles and passenger car bodies
Reconstituted wood products
Refrigeration and heating equipment
Sheet metal work
Wholesale trade
Total Accounted for in Top 10 M/P/S
Total Life Cycle OOP impacts
Remainder
OOP
(gCFC-lleq.)
195.59
44.68
39.72
24.54
16.78
16.09
12.11
12.08
10.03
9.85
381.48
616.98
235.50
Contribution to
Life Cycle OOP
31.70%
7.24%
6.44%
3.98%
2.72%
2.61%
1.96%
1.96%
1.63%
1.60%
61.83%
100.00%
38.17%
• Mineral wool
• Miscellaneous plastics
products, n.e.c.
• Cut stone and stone products
• Paints and allied products
• Metal doors, sash, frames,
molding, and trim
Motor vehicles and passenger
car bodies
Reconstituted wood products
• Refrigeration and heating
equipment
Sheet metal work
Wholesale trade
Remainder
E-3
-------
APPENDIX El (CONTINUED)
Human Toxicity Potential (HTP) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Brick and structural clay tile
Miscellaneous plastics products, n.e.c.
Motor vehicles and passenger car bodies
Cut stone and stone products
Refrigeration and heating equipment
Mineral wool
Paints and allied products
Retail trade, except eating and drinking
Wholesale trade
Metal doors, sash, frames, molding, and trim
Total Accounted for in Top 10 M/P/S
Total Life Cycle HTP impacts
Remainder
HTP
(kg p-DCB eq.)
1,582.43
836.36
552.86
505.64
472.50
429.60
424.00
420.69
419.58
418.00
6,061.68
16,037.52
9,975.84
Contribution to
Life Cycle HTP
9.87%
5.22%
3.45%
3.15%
2.95%
2.68%
2.64%
2.62%
2.62%
2.61%
37.80%
100.00%
62.20%
• Brick and structural clay tile
• Miscellaneous plastics
products, n.e.c.
• Motor vehicles and passenger
car bodies
• Cut stone and stone products
• Refrigeration and heating
equipment
Mineral wool
Paints and allied products
Retail trade, except eating and
drinking
Wholesale trade
Metal doors, sash, frames,
molding, and trim
Remainder
Freshwater Aquatic Ecotoxicitv Potential (FAETP) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Carpets and rugs
Motor vehicles and passenger car bodies
Miscellaneous plastics products, n.e.c.
Paints and allied products
Wholesale trade
Retail trade, except eating and drinking
Mineral wool
Sawmills and planing mills, general
Brooms and brushes
Refrigeration and heating equipment
Total Accounted for in Top 10 M/P/S
Total Life Cycle FAETP impacts
Remainder
FAETP
(kg p-DCB eq.)
410.12
144.03
133.92
80.12
72.61
71.22
71.12
63.52
55.44
51.40
1,153.50
2,552.07
1,398.58
Contribution to
Life Cycle FAETP
16.07%
5.64%
5.25%
3.14%
2.85%
2.79%
2.79%
2.49%
2.17%
2.01%
45.20%
100.00%
54.80%
• Carpets and rugs
• Motor vehicles and passenger
car bodies
• Miscellaneous plastics
products, n.e.c.
• Paints and allied products
• Wholesale trade
Retail trade, except eating and
drinking
Mineral wool
• Sawmills and planing mills,
general
Brooms and brushes
Refrigeration and heating
equipment
Remainder
E-4
-------
APPENDIX El (CONTINUED)
Marine Aquatic Ecotoxicity Potential (MAETP) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Brick and structural clay tile
Ceramic wall and floor tile
Retail trade, except eating and drinking
Metal doors, sash, frames, molding, and trim
Motor vehicles and passenger car bodies
Miscellaneous plastics products, n.e.c.
Sheet metal work
Wholesale trade
Reconstituted wood products
Refrigeration and heating equipment
Total Accounted for in Top 10 M/P/S
Total Life Cycle MAETP impacts
Remainder
MAETP
(mton p-DCB eq.)
22,021.73
1,933.73
1,410.17
1,409.93
1,113.36
1,082.99
861.55
844.24
791.14
715.49
32,184.32
47,300.18
15,115.86
Contribution to
Life Cycle MAETP
46.56%
4.09%
2.98%
2.98%
2.35%
2.29%
1.82%
1.78%
1.67%
1.51%
68.04%
100.00%
31.96%
• Brick and structural clay tile
• Ceramic wall and floor tile
• Retail trade, except eating and
drinking
• Metal doors, sash, frames,
molding, and trim
• Motor vehicles and passenger
car bodies
Miscellaneous plastics
products, n.e.c.
Sheet metal work
Wholesale trade
Reconstituted wood products
Refrigeration and heating
equipment
Remainder
Terrestrial Ecotoxicitv Potential (TETP) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Carpets and rugs
Miscellaneous plastics products, n.e.c.
Motor vehicles and passenger car bodies
Paints and allied products
Wholesale trade
Mineral wool
Retail trade, except eating and drinking
Refrigeration and heating equipment
Converted paper products, n.e.c.
Sawmills and planing mills, general
Total Accounted for in Top 10 M/P/S
Total Life Cycle TETP impacts
Remainder
TETP
(kg p-DCB eq.)
353.90
172.56
157.09
98.46
91.26
87.95
86.94
80.79
67.79
61.76
1,258.50
3,136.84
1,878.35
Contribution to
Life Cycle TETP
11.28%
5.50%
5.01%
3.14%
2.91%
2.80%
2.77%
2.58%
2.16%
1.97%
40.12%
100.00%
59.88%
• Carpets and rugs
• Miscellaneous plastics
products, n.e.c.
• Motor vehicles and passenger
car bodies
• Paints and allied products
• Wholesale trade
Mineral wool
Retail trade, except eating and
drinking
Refrigeration and heating
equipment
Converted paper products,
n.e.c.
Sawmills and planing mills,
general
Remainder
E-5
-------
APPENDIX El (CONTINUED)
Freshwater Sediment Ecotoxicity Potential (FSETP) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Brick and structural clay tile
Ceramic wall and floor tile
Retail trade, except eating and drinking
Metal doors, sash, frames, molding, and trim
Miscellaneous plastics products, n.e.c.
Motor vehicles and passenger car bodies
Wholesale trade
Sheet metal work
Reconstituted wood products
Refrigeration and heating equipment
Total Accounted for in Top 10 M/P/S
Total Life Cycle FSETP impacts
Remainder
FSETP
(mton p-DCB eq.)
7,254.15
644.28
508.04
502.87
460.30
422.08
325.52
315.45
295.48
287.04
11,015.21
17,124.15
6,108.94
Contribution to
Life Cycle FSETP
42.36%
3.76%
2.97%
2.94%
2.69%
2.46%
1.90%
1.84%
1.73%
1.68%
64.33%
100.00%
35.67%
• Brick and structural clay tile
• Ceramic wall and floor tile
• Retail trade, except eating and
drinking
• Metal doors, sash, frames,
molding, and trim
• Miscellaneous plastics
products, n.e.c.
Motor vehicles and passenger
car bodies
Wholesale trade
Sheet metal work
Reconstituted wood products
Refrigeration and heating
equipment
Remainder
Marine Sediment Ecotoxicitv Potential (MSETP) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Miscellaneous plastics products, n.e.c.
Converted paper products, n.e.c.
Cut stone and stone products
Paints and allied products
Mineral wool
Wholesale trade
Motor vehicles and passenger car bodies
Retail trade, except eating and drinking
Paper coating and glazing
Photographic equipment and supplies
Total Accounted for in Top 10 M/P/S
Total Life Cycle MSETP impacts
Remainder
MSETP
(kg p-DCB eq.)
2,388.02
1,561.77
1,542.86
1,246.47
1,189.26
1,101.21
947.63
883.55
782.29
777.77
12,420.83
29,923.75
17,502.92
Contribution to
Life Cycle MSETP
7.98%
5.22%
5.16%
4.17%
3.97%
3.68%
3.17%
2.95%
2.61%
2.60%
41.51%
100.00%
58.49%
• Miscellaneous plastics
products, n.e.c.
• Converted paper products,
n.e.c.
• Cut stone and stone products
• Paints and allied products
• Mineral wool
• Wholesale trade
Motor vehicles and passenger
car bodies
Retail trade, except eating and
drinking
Paper coating and glazing
Photographic equipment and
supplies
Remainder
E-6
-------
APPENDIX El (CONTINUED)
Photochemical Ozone Creation Potential (POCP) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Ready-mixed concrete
Trucking and courier services, except air
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Motor vehicles and passenger car bodies
Millwork
Reconstituted wood products
Wholesale trade
Mineral wool
Sawmills and planing mills, general
Total Accounted for in Top 10 M/P/S
Total Life Cycle POCP impacts
Remainder
POCP
(kgC4H4eq.)
5.84
5.44
3.53
3.28
3.05
2.76
2.69
2.69
2.59
2.09
33.96
84.96
51.00
Contribution to
Life Cycle POCP
6.87%
6.40%
4.15%
3.86%
3.59%
3.25%
3.17%
3.16%
3.05%
2.46%
39.97%
100.00%
60.03%
• Ready-mixed concrete
• Trucking and courier services,
except air
• Miscellaneous plastics
products, n.e.c.
• Retail trade, except eating and
drinking
• Motor vehicles and passenger
car bodies
• Millwork
Reconstituted wood products
Wholesale trade
Mineral wool
Sawmills and planing mills,
general
Remainder
Acidification Potential (AP) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Ready-mixed concrete
Retail trade, except eating and drinking
Cement, hydraulic
Miscellaneous plastics products, n.e.c.
Reconstituted wood products
Wholesale trade
Motor vehicles and passenger car bodies
Trucking and courier services, except air
Electric services (utilities)
Mineral wool
Total Accounted for in Top 10 M/P/S
Total Life Cycle AP impacts
Remainder
AP
(kgS02eq.)
49.01
26.84
26.68
20.26
17.09
16.81
16.46
15.45
13.48
11.77
213.85
502.36
288.50
Contribution to
Life Cycle AP
9.76%
5.34%
5.31%
4.03%
3.40%
3.35%
3.28%
3.08%
2.68%
2.34%
42.57%
100.00%
57.43%
• Ready-mixed concrete
• Retail trade, except eating and
drinking
Cement, hydraulic
• Miscellaneous plastics
products, n.e.c.
• Reconstituted wood products
• Wholesale trade
Motor vehicles and passenger
car bodies
• Trucking and courier services,
except air
Electric services (utilities)
Mineral wool
Remainder
E-7
-------
APPENDIX El (CONTINUED)
Eutrophication Potential (EP) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Ready-mixed concrete
Trucking and courier services, except air
Miscellaneous plastics products, n.e.c.
Cement, hydraulic
Retail trade, except eating and drinking
Motor vehicles and passenger car bodies
Millwork
Reconstituted wood products
Wholesale trade
Carpets and rugs
Total Accounted for in Top 10 M/P/S
Total Life Cycle EP impacts
Remainder
EP
(kgP04eq.)
5.81
3.50
2.85
2.45
2.40
2.32
2.02
1.98
1.93
1.88
27.14
66.22
39.09
Contribution to
Life Cycle EP
8.78%
5.28%
4.30%
3.70%
3.62%
3.50%
3.05%
2.99%
2.92%
2.85%
40.98%
100.00%
59.02%
• Ready-mixed concrete
• Trucking and courier services,
except air
• Miscellaneous plastics
products, n.e.c.
• Cement, hydraulic
• Retail trade, except eating and
drinking
Motor vehicles and passenger
car bodies
Millwork
Reconstituted wood products
Wholesale trade
Carpets and rugs
Remainder
Energy Consumption (EC) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Reconstituted wood products
Retail trade, except eating and drinking
Wholesale trade
Ready-mixed concrete
Trucking and courier services, except air
Motor vehicles and passenger car bodies
Millwork
Miscellaneous plastics products, n.e.c.
Wood kitchen cabinets
Construction machinery and equipment
Total Accounted for in Top 10 M/P/S
Total Life Cycle EC impacts
Remainder
EC
(mBTU)
87.99
69.86
50.94
47.48
43.99
39.94
39.13
36.67
32.59
29.29
477.90
1,216.21
738.31
Contribution to
Life Cycle EC
7.24%
5.74%
4.19%
3.90%
3.62%
3.28%
3.22%
3.02%
2.68%
2.41%
39.29%
100.00%
60.71%
• Reconstituted wood products
• Retail trade, except eating and
drinking
• Wholesale trade
• Ready-mixed concrete
• Trucking and courier services,
except air
Motor vehicles and passenger
car bodies
Millwork
Miscellaneous plastics
products, n.e.c.
Wood kitchen cabinets
Construction machinery and
equipment
Remainder
E-8
-------
APPENDIX El (CONTINUED)
Water Consumption (WC) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Retail trade, except eating and drinking
Electric services (utilities)
Reconstituted wood products
Wholesale trade
Miscellaneous plastics products, n.e.c.
Ready-mixed concrete
Motor vehicles and passenger car bodies
Mineral wool
Millwork
Construction machinery and equipment
Total Accounted for in Top 10 M/P/S
Total Life Cycle WC impacts
Remainder
WC
(103gal)
1,210.07
784.47
662.20
616.75
568.87
461.51
450.08
417.25
291.45
287.76
5,750.41
12,804.20
7,053.79
Contribution to
Life Cycle WC
9.45%
6.13%
5.17%
4.82%
4.44%
3.60%
3.52%
3.26%
2.28%
2.25%
44.91%
100.00%
55.09%
• Retail trade, except eating and
drinking
• Electric services (utilities)
• Reconstituted wood products
• Wholesale trade
• Miscellaneous plastics
products, n.e.c.
• Ready-mixed concrete
Motor vehicles and passenger
car bodies
Mineral wool
Millwork
Construction machinery and
equipment
Remainder
Material Input (MTL) - Input Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Dimension, crushed and broken stone
Sand and gravel
Ready-mixed concrete
Asphalt paving mixtures and blocks
Concrete block and brick
Sawmills and planing mills, general
Gypsum products
Reconstituted wood products
Cement, hydraulic
Cut stone and stone products
Total Accounted for in Top 10 M/P/S
Total Life Cycle MTL impacts
Remainder
MTL
(mton)
754.64
656.15
420.45
127.94
72.88
49.37
40.79
39.06
37.98
33.88
2,233.14
2,668.70
435.55
Contribution to
Life Cycle MTL
28.28%
24.59%
15.76%
4.79%
2.73%
1.85%
1.53%
1.46%
1.42%
1.27%
83.68%
100.00%
16.32%
• Dimension, crushed and
broken stone
• Sand and gravel
• Ready-mixed concrete
• Asphalt paving mixtures and
blocks
• Concrete block and brick
• Sawmills and planing mills,
general
Gypsum products
Reconstituted wood products
Cement, hydraulic
Cut stone and stone products
Remainder
E-9
-------
APPENDIX El (CONTINUED)
Waste (WST) - Input Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Sand and gravel
Ready-mixed concrete
Asphalt paving mixtures and blocks
Sawmills and planing mills, general
Reconstituted wood products
Millwork
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Petroleum refining
Wood preserving
Total Accounted for in Top 10 M/P/S
Total Life Cycle WST impacts
Remainder
WST
(mton)
11.88
8.15
7.00
6.94
5.79
4.09
3.86
3.15
2.90
2.90
56.68
117.95
61.28
Contribution to
Life Cycle WST
10.07%
6.91%
5.94%
5.88%
4.91%
3.47%
3.28%
2.67%
2.46%
2.46%
48.05%
100.00%
51.95%
• Sand and gravel
• Ready-mixed concrete
• Asphalt paving mixtures and
blocks
• Sawmills and planing mills,
general
• Reconstituted wood products
• Millwork
Miscellaneous plastics
products, n.e.c.
Retail trade, except eating and
drinking
Petroleum refining
Wood preserving
Remainder
E-10
-------
APPENDIX E2 -VECTOR ANALYSIS RESULTS, INPUT CONTRIBUTION BASIS, PRE-OCCUPANCY PHASE
All Impacts
Rank
1
2
3
4
5
6
7
8
9
10
Description
Brick and structural clay tile
Ready-mixed concrete
Carpets and rugs
Mineral wool
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Trucking and courier services, except air
Reconstituted wood products
Sand and gravel
Motor vehicles and passenger car bodies
Number of Standard Deviations from the Mean
Q_
0
<
0.69
4.36
0.06
2.73
3.68
4.17
2.05
3.21
0.40
2.60
o
^
_i
-0.18
1.10
2.41
0.99
2.23
2.20
7.27
2.67
-0.26
2.19
Q_
g
0.60
7.96
0.04
2.94
3.18
3.79
3.18
3.29
0.37
3.00
Q.
O
0
-0.12
0.39
0.11
13.30
2.88
0.40
0.04
0.63
-0.16
0.90
Q_
h-
9.30
1.60
0.40
2.17
4.69
2.12
0.40
1.50
-0.09
2.93
Q_
1—
LU
<
LL.
-0.17
0.57
11.61
1.71
3.54
1.71
0.50
1.01
-0.27
3.84
Q.
1—
LU
<
14.02
0.23
-0.02
0.24
0.55
0.76
0.05
0.36
-0.06
0.57
Q.
1—
LU
h-
-0.23
0.79
9.93
2.13
4.61
2.10
0.57
1.30
-0.33
4.16
Q_
1—
LU
to
l_l_
13.97
0.26
0.01
0.32
0.73
0.83
0.07
0.41
-0.07
0.66
Q.
1—
LU
to
-0.28
1.19
0.61
3.45
7.41
2.43
0.32
1.99
-0.36
2.65
Q.
O
0
Q.
0.09
6.54
0.00
2.62
3.75
3.45
6.06
2.75
-0.08
3.17
£
-0.01
8.62
0.05
1.72
3.30
4.51
2.41
2.71
0.09
2.59
Q_
LU
0.02
8.09
2.30
1.86
3.72
3.05
4.67
2.43
-0.10
2.94
o
LU
0.18
3.52
-0.07
1.97
2.61
5.42
3.23
6.96
0.59
2.88
£
0.09
2.83
0.16
2.52
3.60
8.16
0.94
4.26
0.56
2.75
_i
-0.12
5.35
-0.14
0.04
0.05
0.14
-0.07
0.34
8.45
0.02
i—
0.21
5.36
0.01
1.45
2.32
1.82
0.86
3.69
8.00
1.31
Vector
Magnitude
21.89
18.68
15.65
15.62
14.57
14.02
12.01
11.79
11.69
10.62
Rank
1
2
3
4
5
6
7
8
9
10
Description
Brick and structural clay tile
Ready-mixed concrete
Carpets and rugs
Mineral wool
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Trucking and courier services, except air
Reconstituted wood products
Sand and gravel
Motor vehicles and passenger car bodies
Factor Influence (change in vector orientation, in degrees)
Q_
0
<
2
13
0
10
15
17
10
16
2
14
o
^
_i
0
3
9
4
9
9
37
13
-1
12
Q_
O
2
25
0
11
13
16
15
16
2
16
Q.
Q
0
0
1
0
58
11
2
0
3
-1
5
Q.
1—
I
25
5
1
8
19
9
2
7
0
16
LU
<
LL.
0
2
48
6
14
7
2
5
-1
21
LU
<
40
1
0
1
2
3
0
2
0
3
i—
LU
h-
-1
2
39
8
18
9
3
6
-2
23
LU
to
l_l_
40
1
0
1
3
3
0
2
0
4
LU
to
-1
4
2
13
31
10
2
10
-2
14
o
0
Q.
0
20
0
10
15
14
30
13
0
17
£
0
27
0
6
13
19
12
13
0
14
Q_
LU
0
26
8
7
15
13
23
12
0
16
o
LU
0
11
0
7
10
23
16
36
3
16
£
0
9
1
9
14
36
4
21
3
15
_i
0
17
-1
0
0
1
0
2
46
0
6
1
17
0
5
9
7
4
18
43
7
E-ll
-------
APPENDIX E2 (CONTINUED)
Natural Resources and Land Use Impact Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Sand and gravel
Retail trade, except eating and drinking
Dimension, crushed and broken stone
Ready-mixed concrete
Reconstituted wood products
Sawmills and planing mills, general
Asphalt paving mixtures and blocks
Trucking and courier services, except air
Wholesale trade
Miscellaneous plastics products, n.e.c.
Number of Standard Deviations from the
Mean
Q.
O
<
0.40
4.17
0.92
4.36
3.21
0.72
7.26
2.05
2.95
3.68
o
_i
-0.26
2.20
-0.15
1.10
2.67
7.85
0.06
7.27
1.94
2.23
o
LU
0.59
5.42
1.10
3.52
6.96
1.97
1.22
3.23
3.82
2.61
o
0.56
8.16
0.97
2.83
4.26
1.16
0.84
0.94
3.94
3.60
_i
i—
8.45
0.14
9.74
5.35
0.34
0.48
1.51
-0.07
0.04
0.05
i—
8.00
1.82
0.41
5.36
3.69
4.50
4.55
0.86
1.33
2.32
Vector
Magnitude
11.67
11.02
9.90
9.90
9.89
9.37
8.82
8.31
6.65
6.61
Factor Influence (change in
vector orientation, in degrees)
Q.
O
<
2
22
5
26
19
4
55
14
26
34
o
_i
-1
12
-1
6
16
57
0
61
17
20
o
LU
3
29
6
21
45
12
8
23
35
23
o
3
48
6
17
26
7
5
6
36
33
_i
i—
46
1
80
33
2
3
10
0
0
0
i—
43
10
2
33
22
29
31
6
12
21
Toxicity Impact Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Brick and structural clay tile
Carpets and rugs
Miscellaneous plastics products, n.e.c.
Motor vehicles and passenger car bodies
Cut stone and stone products
Converted paper products, n.e.c.
Paints and allied products
Mineral wool
Wholesale trade
Retail trade, except eating and drinking
Number of Standard Deviations
from the Mean
Q_
h-
9.30
0.40
4.69
2.93
2.64
2.00
2.14
2.17
2.11
2.12
Q_
1—
LU
<
l_l_
-0.17
11.61
3.54
3.84
0.48
0.77
1.97
1.71
1.75
1.71
Q.
1—
LU
<
14.02
-0.02
0.55
0.57
-0.02
0.04
0.16
0.24
0.39
0.76
Q.
1—
LU
h-
-0.23
9.93
4.61
4.16
1.22
1.54
2.44
2.13
2.23
2.10
Q.
1—
LU
to
LL.
13.97
0.01
0.73
0.66
0.07
0.13
0.25
0.32
0.47
0.83
Q_
1—
LU
-0.28
0.61
7.41
2.65
4.61
4.68
3.63
3.45
3.15
2.43
Vector
Magnitude
21.87
15.29
10.56
6.96
5.48
5.37
5.26
4.92
4.78
4.36
Factor Influence (change in vector
orientation, in degrees)
Q_
h-
25
1
26
25
29
22
24
26
26
29
Q_
1—
LU
<
l_l_
0
49
20
34
5
8
22
20
22
23
Q.
1—
LU
<
40
0
3
5
0
0
2
3
5
10
Q.
1—
LU
h-
-1
40
26
37
13
17
28
26
28
29
Q.
1—
LU
to
LL.
40
0
4
5
1
1
3
4
6
11
Q_
1—
LU
-1
2
45
22
57
61
44
44
41
34
E-12
-------
APPENDIX E2 (CONTINUED)
Pollution Impacts Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Ready-mixed concrete
Mineral wool
Trucking and courier services, except air
Miscellaneous plastics products, n.e.c.
Retail trade, except eating and drinking
Cement, hydraulic
Motor vehicles and passenger car bodies
Reconstituted wood products
Wholesale trade
Millwork
Number of Standard Deviations
from the Mean
o
7.96
2.94
3.18
3.18
3.79
3.00
3.00
3.29
2.61
1.78
Q.
O
0
0.39
13.30
0.04
2.88
0.40
-0.15
0.90
0.63
0.47
0.11
o
O Q-
Q.
6.54
2.62
6.06
3.75
3.45
1.80
3.17
2.75
2.74
2.83
£
8.62
1.72
2.41
3.30
4.51
4.48
2.59
2.71
2.66
1.60
Q.
LU
8.09
1.86
4.67
3.72
3.05
3.13
2.94
2.43
2.37
2.50
Vector
Magnitude
15.69
14.10
8.63
7.56
7.49
6.49
5.94
5.66
5.21
4.47
Factor Influence (change in vector
orientation, in degrees)
Q_
O
30
12
22
25
30
28
30
36
30
24
Q.
Q
0
1
71
0
22
3
-1
9
6
5
1
o
O Q-
Q.
25
11
45
30
27
16
32
29
32
39
£
33
7
16
26
37
44
26
29
31
21
Q.
LU
31
8
33
29
24
29
30
25
27
34
E-13
-------
APPENDIX E3 - OCCUPANCY-PHASE RESULTS BY IMPACT CATEGORY
Abiotic Depletion Potential (ADP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas distribution
Roofing (asphalt shingle)
Petroleum refining
Other
Doors/Windows
Plastics
Siding (wood shingle)
Lumber
Insulation (glass fiber)
Total Accounted for in Top 10 M/P/S
Total Life Cycle ADP impacts
Remainder
ADP
(kgSneq.)
2,304.47
1,540.98
226.84
189.29
118.23
42.74
39.80
28.18
27.37
27.13
4,545.05
4,651.36
106.32
Contribution to
Life Cycle ADP
49.54%
33.13%
4.88%
4.07%
2.54%
0.92%
0.86%
0.61%
0.59%
0.58%
97.71%
100.00%
2.29%
Land Use Competition (LUC) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Siding (wood shingle)
Carpeting
Lumber
Electric services (utilities)
Other
Doors/Windows
Plastics
Natural gas distribution
Roofing (asphalt shingle)
Hardware
Total Accounted for in Top 10 M/P/S
Total Life Cycle LUC impacts
Remainder
LUC
(m2*yr)
7,297.21
4,342.91
2,786.35
2,513.70
2,227.95
965.74
945.79
934.61
648.91
458.06
23,121.23
24,601.79
1,480.57
Contribution to
Life Cycle LUC
29.66%
17.65%
11.33%
10.22%
9.06%
3.93%
3.84%
3.80%
2.64%
1.86%
93.98%
100.00%
6.02%
• Electric services (utilities)
• Natural gas distribution
• Roofing (asphalt shingle)
• Petroleum refining
• Other
Doors/Windows
Plastics
Siding (wood shingle)
Lumber
• Insulation (glass fiber)
Remainder
• Siding (wood shingle)
• Carpeting
• Lumber
• Electric services (utilities)
• Other
Doors/Windows
Plastics
Natural gas distribution
Roofing (asphalt shingle)
Hardware
Remainder
E-14
-------
APPENDIX E3 (CONTINUED)
Global Warming Potential (GWP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas distribution
Other
Roofing (asphalt shingle)
Doors/Windows
Siding (wood shingle)
Plastics
Lumber
Insulation (glass fiber)
Hardware
Total Accounted for in Top 10 M/P/S
Total Life Cycle GWP impacts
Remainder
GWP
(kgC02eq.)
584,041.14
39,560.78
32,850.79
18,175.33
12,647.94
9,648.96
9,156.41
9,138.04
7,586.78
7,501.54
730,307.71
758,781.76
28,474.05
Contribution to
Life Cycle GWP
76.97%
5.21%
4.33%
2.40%
1.67%
1.27%
1.21%
1.20%
1.00%
0.99%
96.25%
100.00%
3.75%
Stratospheric Ozone Depletion Potential (OOP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Insulation (glass fiber)
Other
Doors/Windows
Electric services (utilities)
Plastics
Carpeting
Roofing (asphalt shingle)
Hardware
Natural gas distribution
Electrical
Total Accounted for in Top 10 M/P/S
Total Life Cycle OOP impacts
Remainder
OOP
(gCFC-lleq.)
327.77
297.77
99.77
85.30
84.57
38.00
36.19
32.41
30.79
27.87
1,060.43
1,138.08
77.65
Contribution to
Life Cycle OOP
28.80%
26.16%
8.77%
7.49%
7.43%
3.34%
3.18%
2.85%
2.71%
2.45%
93.18%
100.00%
6.82%
• Electric services (utilities)
• Natural gas distribution
• Other
• Roofing (asphalt shingle)
• Doors/Windows
• Siding (wood shingle)
Plastics
Lumber
Insulation (glass fiber)
Hardware
Remainder
• Insulation (glass fiber)
• Other
• Doors/Windows
• Electric services (utilities)
• Plastics
Carpeting
Roofing (asphalt shingle)
Hardware
Natural gas distribution
Electrical
Remainder
E-15
-------
APPENDIX E3 (CONTINUED)
Human Toxicity Potential (HTP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Other
Doors/Windows
Plastics
Hardware
Roofing (asphalt shingle)
Natural gas distribution
Carpeting
Electrical
Insulation (glass fiber)
Total Accounted for in Top 10 M/P/S
Total Life Cycle HTP impacts
Remainder
HTP
(kg p-DCB eq.)
21,585.86
4,181.72
2,464.33
1,569.51
1,335.01
1,243.25
1,172.09
1,149.87
895.98
713.86
36,311.48
38,712.02
2,400.54
Contribution to
Life Cycle HTP
55.76%
10.80%
6.37%
4.05%
3.45%
3.21%
3.03%
2.97%
2.31%
1.84%
93.80%
100.00%
6.20%
Freshwater Aquatic Ecotoxicitv Potential (TAETP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Carpeting
Electric services (utilities)
Other
Siding (wood shingle)
Plastics
Doors/Windows
Roofing (asphalt shingle)
Hardware
Natural gas distribution
Lumber
Total Accounted for in Top 10 M/P/S
Total Life Cycle FAETP impacts
Remainder
FAETP (kg p-DCB
eq.)
2,868.24
690.79
437.48
252.50
217.99
189.95
135.32
129.09
128.90
127.59
5,177.87
5,482.93
305.07
Contribution to
Life Cycle FAETP
52.31%
12.60%
7.98%
4.61%
3.98%
3.46%
2.47%
2.35%
2.35%
2.33%
94.44%
100.00%
5.56%
• Electric services (utilities)
• Other
Doors/Windows
• Plastics
• Hardware
Roofing (asphalt shingle)
Natural gas distribution
Carpeting
Electrical
• Insulation (glass fiber)
Remainder
• Carpeting
• Electric services (utilities)
• Other
• Siding (wood shingle)
• Plastics
• Doors/Windows
Roofing (asphalt shingle)
Hardware
Natural gas distribution
• Lumber
Remainder
E-16
-------
APPENDIX E3 (CONTINUED)
Marine Aquatic Ecotoxicity Potential (MAETP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Doors/Windows
Other
Natural gas distribution
Roofing (asphalt shingle)
Plastics
Hardware
Carpeting
Electrical
Lumber
Total Accounted for in Top 10 M/P/S
Total Life Cycle MAETP impacts
Remainder
MAETP
(mton p-DCB eq.)
215,239.91
8,393.52
6,073.57
2,602.51
2,162.07
2,052.19
1,919.52
1,636.52
1,351.70
1,303.13
242,734.65
246,592.22
3,857.56
Contribution to
Life Cycle MAETP
87.29%
3.40%
2.46%
1.06%
0.88%
0.83%
0.78%
0.66%
0.55%
0.53%
98.44%
100.00%
1.56%
Terrestrial Ecotoxicitv Potential (TETP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Carpeting
Electric services (utilities)
Other
Doors/Windows
Plastics
Siding (wood shingle)
Hardware
Roofing (asphalt shingle)
Natural gas distribution
Lumber
Total Accounted for in Top 10 M/P/S
Total Life Cycle TETP impacts
Remainder
TETP
(kg p-DCB eq.)
2,596.85
979.73
662.02
302.41
294.73
257.56
206.05
187.21
173.07
149.47
5,809.11
6,252.11
443.00
Contribution to
Life Cycle TETP
41.54%
15.67%
10.59%
4.84%
4.71%
4.12%
3.30%
2.99%
2.77%
2.39%
92.91%
100.00%
7.09%
• Electric services (utilities)
• Doors/Windows
• Other
• Natural gas distribution
• Roofing (asphalt shingle)
• Plastics
Hardware
• Carpeting
Electrical
Lumber
Remainder
• Carpeting
• Electric services (utilities)
Other
• Doors/Windows
• Plastics
Siding (wood shingle)
• Hardware
Roofing (asphalt shingle)
Natural gas distribution
Lumber
Remainder
E-17
-------
APPENDIX E3 (CONTINUED)
Freshwater Sediment Ecotoxicity Potential (FSETP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Doors/Windows
Other
Natural gas distribution
Plastics
Roofing (asphalt shingle)
Hardware
Carpeting
Electrical
Lumber
Total Accounted for in Top 10 M/P/S
Total Life Cycle FSETP impacts
Remainder
FSETP
(mton p-DCB eq.)
71,547.77
2,993.18
2,472.46
959.44
872.10
840.70
772.94
704.60
543.12
493.40
82,199.72
83,747.98
1,548.26
Contribution to
Life Cycle FSETP
85.43%
3.57%
2.95%
1.15%
1.04%
1.00%
0.92%
0.84%
0.65%
0.59%
98.15%
100.00%
1.85%
Marine Sediment Ecotoxicitv Potential (MSETP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Other
Electric services (utilities)
Plastics
Doors/Windows
Roofing (asphalt shingle)
Carpeting
Natural gas distribution
Insulation (glass fiber)
Electrical
Hardware
Total Accounted for in Top 10 M/P/S
Total Life Cycle MSETP impacts
Remainder
MSETP
(kg p-DCB eq.)
8,429.85
4,856.76
4,513.11
4,102.23
2,905.98
2,682.28
2,102.11
1,990.18
1,852.87
1,657.96
35,093.34
41,601.17
6,507.83
Contribution to
Life Cycle MSETP
20.26%
11.67%
10.85%
9.86%
6.99%
6.45%
5.05%
4.78%
4.45%
3.99%
84.36%
100.00%
15.64%
APPENDIX E3 (CONTINUED)
• Electric services (utilities)
• Doors/Windows
• Other
• Natural gas distribution
• Plastics
Roofing (asphalt shingle)
Hardware
• Carpeting
Electrical
Lumber
Remainder
• Other
• Electric services (utilities)
• Plastics
• Doors/Windows
• Roofing (asphalt shingle)
Carpeting
Natural gas distribution
Insulation (glass fiber)
Electrical
• Hardware
Remainder
E-18
-------
Photochemical Ozone Creation Potential (POCP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas distribution
Other
Siding (wood shingle)
Doors/Windows
Roofing (asphalt shingle)
Lumber
Plastics
Hardware
Electrical
Total Accounted for in Top 10 M/P/S
Total Life Cycle POCP impacts
Remainder
POCP
(kgC4H4eq.)
173.28
16.22
15.45
7.10
6.53
6.28
5.35
4.91
3.37
3.24
241.72
253.35
11.62
Contribution to
Life Cycle POCP
68.40%
6.40%
6.10%
2.80%
2.58%
2.48%
2.11%
1.94%
1.33%
1.28%
95.41%
100.00%
4.59%
Acidification Potential (AP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas distribution
Other
Roofing (asphalt shingle)
Doors/Windows
Plastics
Siding (wood shingle)
Lumber
Hardware
Petroleum refining
Total Accounted for in Top 10 M/P/S
Total Life Cycle AP impacts
Remainder
AP
(kgS02eq.)
4,344.39
162.73
123.52
62.87
58.58
40.70
37.61
35.76
29.96
29.50
4,925.61
5,022.33
96.73
Contribution to
Life Cycle AP
86.50%
3.24%
2.46%
1.25%
1.17%
0.81%
0.75%
0.71%
0.60%
0.59%
98.07%
100.00%
1.93%
• Electric services (utilities)
• Natural gas distribution
Other
• Siding (wood shingle)
• Doors/Windows
Roofing (asphalt shingle)
Lumber
• Plastics
Hardware
Electrical
Remainder
• Electric services (utilities)
• Natural gas distribution
• Other
• Roofing (asphalt shingle)
• Doors/Windows
• Plastics
Siding (wood shingle)
Lumber
Hardware
• Petroleum refining
Remainder
APPENDIX E3 (CONTINUED)
E-19
-------
Eutrophication Potential (EP) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas distribution
Carpeting
Other
Roofing (asphalt shingle)
Siding (wood shingle)
Doors/Windows
Plastics
Lumber
Petroleum refining
Total Accounted for in Top 10 M/P/S
Total Life Cycle EP impacts
Remainder
EP
(kgP04eq.)
166.52
20.76
12.02
11.37
6.12
5.68
4.65
4.23
4.17
2.43
237.95
247.40
9.45
Contribution to
Life Cycle EP
67.31%
8.39%
4.86%
4.60%
2.47%
2.30%
1.88%
1.71%
1.69%
0.98%
96.18%
100.00%
3.82%
Energy Consumption (EC) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Other
Natural gas distribution
Roofing (asphalt shingle)
Lumber
Siding (wood shingle)
Doors/Windows
Hardware
Plastics
Electrical
Total Accounted for in Top 10 M/P/S
Total Life Cycle EC impacts
Remainder
EC
(mBTU)
11,266.92
616.77
400.95
276.10
218.34
209.49
173.88
107.92
107.82
87.46
13,465.65
13,783.16
317.51
Contribution to
Life Cycle EC
81.74%
4.47%
2.91%
2.00%
1.58%
1.52%
1.26%
0.78%
0.78%
0.63%
97.70%
100.00%
2.30%
• Electric services (utilities)
• Natural gas distribution
• Carpeting
• Other
• Roofing (asphalt shingle)
• Siding (wood shingle)
Doors/Windows
Plastics
Lumber
Petroleum refining
Remainder
• Electric services (utilities)
• Other
• Natural gas distribution
• Roofing (asphalt shingle)
• Lumber
Siding (wood shingle)
Doors/Windows
• Hardware
Plastics
Electrical
Remainder
APPENDIX E3 (CONTINUED)
E-20
-------
Water Consumption (WC) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Other
Natural gas distribution
Doors/Windows
Lumber
Roofing (asphalt shingle)
Plastics
Siding (wood shingle)
Hardware
Insulation (glass fiber)
Total Accounted for in Top 10 M/P/S
Total Life Cycle WC impacts
Remainder
WC
(10s gal)
239,589.13
2,938.43
1,874.13
1,259.02
1,153.52
1,131.80
1,083.24
1,052.75
763.76
703.53
251,549.30
253,807.60
2,258.30
Contribution to
Life Cycle WC
94.40%
1.16%
0.74%
0.50%
0.45%
0.45%
0.43%
0.41%
0.30%
0.28%
99.11%
100.00%
0.89%
Material Input (MTL) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas distribution
Roofing (asphalt shingle)
Siding (wood shingle)
Lumber
Other
Drywall
Petroleum refining
Doors/Windows
Plastics
Total Accounted for in Top 10 M/P/S
Total Life Cycle MTL impacts
Remainder
MTL
(mton)
401.85
184.19
106.83
97.85
62.10
50.53
39.88
30.89
16.85
13.91
1,004.87
1,049.69
44.82
Contribution to
Life Cycle MTL
38.28%
17.55%
10.18%
9.32%
5.92%
4.81%
3.80%
2.94%
1.61%
1.33%
95.73%
100.00%
4.27%
• Electric services (utilities)
• Other
Natural gas distribution
• Doors/Windows
• Lumber
Roofing (asphalt shingle)
Plastics
Siding (wood shingle)
Hardware
• Insulation (glass fiber)
Remainder
• Electric services (utilities)
• Natural gas distribution
Roofing (asphalt shingle)
• Siding (wood shingle)
• Lumber
• Other
Drywall
Petroleum refining
Doors/Windows
Plastics
Remainder
APPENDIX E3 (CONTINUED)
E-21
-------
Waste (WST) - Input Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas distribution
Roofing (asphalt shingle)
Lumber
Siding (wood shingle)
Petroleum refining
Other
Plastics
Doors/Windows
Carpeting
Total Accounted for in Top 10 M/P/S
Total Life Cycle WST impacts
Remainder
WST
(mton)
272.15
149.31
43.34
36.46
34.38
27.69
20.58
7.84
7.10
5.21
604.07
623.03
18.96
Contribution to
Life Cycle WST
43.68%
23.97%
6.96%
5.85%
5.52%
4.44%
3.30%
1.26%
1.14%
0.84%
96.96%
100.00%
3.04%
• Electric services (utilities)
• Natural gas distribution
Roofing (asphalt shingle)
• Lumber
• Siding (wood shingle)
• Petroleum refining
Other
• Plastics
Doors/Windows
Carpeting
Remainder
E-22
-------
APPENDIX F - RATIONALE FOR SELECTING DIRECT INPUTS FOR SUPPLY CHAIN ANALYSIS
Material/Product/Service
Asphalt paving mixtures and blocks (Pre-occupancy)
Brick and structural clay tile (Pre-occupancy)
Carpeting (Occupancy)/Carpets and Rugs (Pre-occupancy)
Cement, hydraulic (Pre-occupancy)
Converted paper products, n.e.c. (Pre-occupancy)
Cut stone and stone products (Pre-occupancy)
Dimension, crushed and broken stone (Pre-occupancy)
Direct construction (Construction)
Doors/Windows (Occupancy)
Electric services (utilities) (Occupancy)
Electrical (Occupancy)
Hardware (Occupancy)
Insulation (glass fiber) (Occupancy)/Mineral wool (Pre-occupancy)
Lumber (Occupancy)
Millwork (Pre-occupancy)
Miscellaneous plastics products, n.e.c. (Pre-occupancy)
Motor vehicles and passenger car bodies (Pre-occupancy)
Natural gas distribution (Occupancy)
Other (Occupancy)
Paints and allied products (Pre-occupancy)
Plastics (Occupancy)
Ready-mixed concrete (Pre-occupancy)
Reconstituted wood products (Pre-occupancy)
Retail trade, except eating and drinking (Pre-occupancy)
Roofing (asphalt shingle) (Occupancy)
Sand and gravel (Pre-occupancy)
Sawmills and planing mills, general (Pre-occupancy)
Siding (wood shingle) (Occupancy)
Trucking and courier services, except air (Pre-occupancy)
Wholesale trade (Pre-occupancy)
Well-defined
Matl/Prod
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
No
Yes
Yes
No
Yes
Yes
Yes
Yes
No
No
Rank
All
Phases
...
18
2/17
...
...
—
14
3
8
1/~-
19
15
7/10
11
...
13
...
5
4
...
9
...
...
...
12
16
20
6
—
—
Pre-Occ
Only
14
1
»-/3
17
20
18
12
—
—
~-/19
—
...
-/4
...
15
5
10
...
...
16
...
2
8
6
—
9
11
—
7
13
Include?
No
Yes
No
No
No
No
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
Yes
Yes
No
No
No
No
Yes
No
No
Rationale
Relatively lower ranking
High ranking pre-occ
See 3.1.1
Relatively lower ranking
Relatively lower ranking
Relatively lower ranking
Relatively lower ranking
Not well-defined matl/prod
Relatively lower ranking
Not well-defined matl/prod
Relatively lower ranking
Relatively lower ranking
High rank pre-occ, detailed OCA item
Relatively lower ranking
Relatively lower ranking
Not well-defined matl/prod
Relatively lower ranking
Not well-defined matl/prod
Not well-defined matl/prod
Relatively lower ranking
Not well-defined matl/prod
High rank pre-occ, detailed OCA item
Detailed OCA item
Not well-defined matl/prod
Relatively lower ranking
Relatively lower ranking
Relatively lower ranking
High rank all phase
Not well-defined matl/prod
Not well-defined matl/prod
F-l
-------
APPENDIX G - OUTPUT CONTRIBUTION ANALYSIS RESULTS
Appendix Gl - Pre-Occupancy-Phase Results by Impact Category
Appendix G2 - Vector Analysis Results, Output Contribution Basis, Pre-Occupancy Phase
Appendix G3 - Occupancy-Phase Results by Impact Category
Appendix G4 - Vector Analysis Results, Output Contribution Basis, Occupancy Phase
G-l
-------
APPENDIX Gl - PRE-OCCUPANCY-PHASE RESULTS BY IMPACT CATEGORY
Abiotic Depletion Potential (ADP) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Crude petroleum and natural gas
Coal
Petroleum refining
Industrial inorganic and organic chemicals
Dimension, crushed and broken stone
Explosives
Copper ore
Iron and ferroalloy ores, and misc. metal ores...
Nonferrous metal ores, except copper
Nonmetallic mineral services and misc.
Total Accounted for in Top 10 M/P/S
Total Life Cycle ADP impacts
Remainder
ADP
(kgSneq.)
279.82
203.72
14.57
0.38
0.14
0.14
0.00
0.00
0.00
0.00
498.78
498.78
0.00
Contribution to
Life Cycle ADP
56.10%
40.84%
2.92%
0.08%
0.03%
0.03%
0.00%
0.00%
0.00%
0.00%
100.00%
100.00%
0.00%
• Crude petroleum and natural
gas
• Coal
i Petroleum refining
• Industrial inorganic and
organic chemicals
• Dimension, crushed and
broken stone
• Explosives
Copper ore
Land Use Competition (LUC) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Trucking and courier services, except air
Meat animals
Agricultural, forestry, and fishery services
Poultry and eggs
Food grains
Miscellaneous livestock
Cotton
Miscellaneous crops
Forestry products
Dairy farm products
Total Accounted for in Top 10 M/P/S
Total Life Cycle LUC impacts
Remainder
LUC
(m2*yr)
2,325.17
1,320.90
1,164.90
1,159.85
1,072.84
1,000.68
790.84
662.71
563.04
494.43
10,555.35
11,002.07
446.71
Contribution to
Life Cycle LUC
21.13%
12.01%
10.59%
10.54%
9.75%
9.10%
7.19%
6.02%
5.12%
4.49%
95.94%
100.00%
4.06%
• Trucking and courier services,
except air
• Meat animals
I Agricultural, forestry, and
fishery services
• Poultry and eggs
• Food grains
• Miscellaneous livestock
Cotton
• Miscellaneous crops
Forestry products
Dairy farm products
Remainder
G-2
-------
APPENDIX Gl (CONTINUED)
Global Warming Potential (GWP) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Blast furnaces and steel mills
Cement, hydraulic
Trucking and courier services, except air
Sanitary services, steam supply, and irrigation...
Crude petroleum and natural gas
Ready-mixed concrete
Petroleum refining
Lime
Mineral wool
Total Accounted for in Top 10 M/P/S
Total Life Cycle GWP impacts
Remainder
GWP
(kgC02eq.)
29,276.15
11,713.89
11,540.82
6,770.89
5,877.50
5,083.36
2,812.22
2,619.91
2,592.95
2,425.57
80,713.26
141,403.66
60,690.40
Contribution to
Life Cycle GWP
20.70%
8.28%
8.16%
4.79%
4.16%
3.59%
1.99%
1.85%
1.83%
1.72%
57.08%
100.00%
42.92%
• Electric services (utilities)
• Blast furnaces and steel mills
• Cement, hydraulic
• Trucking and courier services,
except air
• Sanitary services, steam
supply, and irrigation systems
• Crude petroleum and natural
gas
Ready-mixed concrete
Petroleum refining
Lime
Mineral wool
Remainder
Stratospheric Ozone Depletion Potential (OOP) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Mineral wool
Industrial inorganic and organic chemicals
Primary aluminum
Cut stone and stone products
Plastics materials and resins
Miscellaneous repair shops
Synthetic rubber
Primary nonferrous metals, n.e.c.
Miscellaneous plastics products, n.e.c.
Surface active agents
Total Accounted for in Top 10 M/P/S
Total Life Cycle OOP impacts
Remainder
OOP
(gCFC-lleq.)
189.49
110.37
39.95
39.16
32.09
23.43
20.79
16.61
11.85
8.95
492.69
616.98
124.28
Contribution to
Life Cycle OOP
30.71%
17.89%
6.47%
6.35%
5.20%
3.80%
3.37%
2.69%
1.92%
1.45%
79.86%
100.00%
20.14%
• Mineral wool
• Industrial inorganic and
organic chemicals
• Primary aluminum
• Cut stone and stone products
• Plastics materials and resins
Miscellaneous repair shops
Synthetic rubber
Primary nonferrous metals,
n.e.c.
Miscellaneous plastics
products, n.e.c.
Surface active agents
Remainder
G-3
-------
APPENDIX Gl (CONTINUED)
Human Toxicity Potential (HTP) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Brick and structural clay tile
Copper ore
Industrial inorganic and organic chemicals
Electric services (utilities)
Paper and paperboard mills
Primary smelting and refining of copper
Nonmetallic mineral products, n.e.c.
Primary aluminum
Pulp mills
Plastics materials and resins
Total Accounted for in Top 10 M/P/S
Total Life Cycle HTP impacts
Remainder
HTP
(kg p-DCB eq.)
1,595.39
1,071.49
1,020.01
943.79
938.76
850.48
842.73
832.37
812.26
738.91
9,646.19
16,037.52
6,391.32
Contribution to
Life Cycle HTP
9.95%
6.68%
6.36%
5.88%
5.85%
5.30%
5.25%
5.19%
5.06%
4.61%
60.15%
100.00%
39.85%
• Brick and structural clay tile
• Copper ore
• Industrial inorganic and
organic chemicals
• Electric services (utilities)
• Paper and paperboard mills
Primary smelting and refining
of copper
Nonmetallic mineral products,
n.e.c.
Primary aluminum
Pulp mills
Plastics materials and resins
Remainder
Freshwater Aquatic Ecotoxicitv Potential (FAETP) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Cotton
Miscellaneous crops
Sanitary services, steam supply, and irrigation...
Agricultural, forestry, and fishery services
Copper ore
Industrial inorganic and organic chemicals
Paper and paperboard mills
Pulp mills
Plastics materials and resins
Primary smelting and refining of copper
Total Accounted for in Top 10 M/P/S
Total Life Cycle FAETP impacts
Remainder
FAETP
(kg p-DCB eq.)
1,209.80
188.73
133.35
117.16
116.09
64.85
61.80
54.84
52.11
48.45
2,047.17
2,552.07
504.91
Contribution to
Life Cycle FAETP
47.40%
7.40%
5.22%
4.59%
4.55%
2.54%
2.42%
2.15%
2.04%
1.90%
80.22%
100.00%
19.78%
• Cotton
• Miscellaneous crops
• Sanitary services, steam
supply, and irrigation systems
• Agricultural, forestry, and
fishery services
• Copper ore
• Industrial inorganic and
organic chemicals
Paper and paperboard mills
Pulp mills
Plastics materials and resins
• Primary smelting and refining
of copper
Remainder
G-4
-------
APPENDIX Gl (CONTINUED)
Marine Aquatic Ecotoxicity Potential (MAETP) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Brick and structural clay tile
Electric services (utilities)
Primary aluminum
Ceramic wall and floor tile
Sanitary services, steam supply, and irrig...
Industrial inorganic and organic chemicals
Plastics materials and resins
Coal
Paper and paperboard mills
Primary metal products, n.e.c.
Total Accounted for in Top 10 M/P/S
Total Life Cycle MAETP impacts
Remainder
MAETP
(mton p-DCB eq.)
22,576.69
10,677.90
4,871.30
1,794.67
656.37
599.63
573.53
531.05
496.97
417.85
43,195.96
47,300.18
4,104.21
Contribution to
Life Cycle MAETP
47.73%
22.57%
10.30%
3.79%
1.39%
1.27%
1.21%
1.12%
1.05%
0.88%
91.32%
100.00%
8.68%
• Brick and structural clay tile
• Electric services (utilities)
• Primary aluminum
• Ceramic wall and floor tile
• Sanitary services, steam
supply, and irrigation systems
• Industrial inorganic and
organic chemicals
Plastics materials and resins
Coal
Paperand paperboard mills
Primary metal products, n.e.c.
Remainder
Terrestrial Ecotoxicitv Potential (TETP) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Cotton
Copper ore
Sanitary services, steam supply, and irrig...
Miscellaneous crops
Paperand paperboard mills
Industrial inorganic and organic chemicals
Pulp mills
Primary smelting and refining of copper
Plastics materials and resins
Agricultural, forestry, and fishery services
Total Accounted for in Top 10 M/P/S
Total Life Cycle TETP impacts
Remainder
TETP
(kg p-DCB eq.)
1,008.13
243.79
148.87
140.82
136.95
133.46
123.17
105.03
97.08
94.92
2,232.22
3,136.84
904.63
Contribution to
Life Cycle TETP
32.14%
7.77%
4.75%
4.49%
4.37%
4.25%
3.93%
3.35%
3.09%
3.03%
71.16%
100.00%
28.84%
• Cotton
• Copper ore
• Sanitary services, steam
supply, and irrigation systems
• Miscellaneous crops
• Paperand paperboard mills
• Industrial inorganic and
organic chemicals
• Pulp mills
Primary smelting and refining
of copper
Plastics materials and resins
Agricultural, forestry, and
fishery services
Remainder
G-5
-------
APPENDIX Gl (CONTINUED)
Freshwater Sediment Ecotoxicity Potential (FSETP) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Brick and structural clay tile
Electric services (utilities)
Primary aluminum
Ceramic wall and floor tile
Industrial inorganic and organic chemicals
Paper and paperboard mills
Plastics materials and resins
Sanitary services, steam supply, and irrig...
Copper ore
Pulp mills
Total Accounted for in Top 10 M/P/S
Total Life Cycle FSETP impacts
Remainder
FSETP
(mton p-DCB eq.)
7,432.71
3,530.87
1,665.83
591.91
324.76
296.53
296.08
286.29
265.66
221.41
14,912.06
17,124.15
2,212.09
Contribution to
Life Cycle FSETP
43.40%
20.62%
9.73%
3.46%
1.90%
1.73%
1.73%
1.67%
1.55%
1.29%
87.08%
100.00%
12.92%
• Brick and structural clay tile
• Electric services (utilities)
• Primary aluminum
• Ceramic wall and floor tile
• Industrial inorganic and
organic chemicals
Paper and paperboard mills
Plastics materials and resins
Sanitary services, steam
supply, and irrigation systems
Copper ore
• Pulp mills
Remainder
Marine Sediment Ecotoxicitv Potential (MSETP) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Paper and paperboard mills
Industrial inorganic and organic chemicals
Pulp mills
Plastics materials and resins
Photographic equipment and supplies
Primary aluminum
Cut stone and stone products
Synthetic rubber
Gum and wood chemicals
Wood products, n.e.c.
Total Accounted for in Top 10 M/P/S
Total Life Cycle MSETP impacts
Remainder
MSETP
(kg p-DCB eq.)
3,834.64
3,652.88
3,453.02
2,367.06
1,672.66
1,497.69
1,493.28
967.06
939.48
831.80
20,709.57
29,923.75
9,214.18
Contribution to
Life Cycle MSETP
12.81%
12.21%
11.54%
7.91%
5.59%
5.01%
4.99%
3.23%
3.14%
2.78%
69.21%
100.00%
30.79%
• Paperand paperboard mills
I Industrial inorganic and
organic chemicals
• Pulp mills
• Plastics materials and resins
• Photographic equipment and
supplies
Primary aluminum
Cut stone and stone products
Synthetic rubber
Gum and wood chemicals
Wood products, n.e.c.
Remainder
G-6
-------
APPENDIX Gl (CONTINUED)
Photochemical Ozone Creation Potential (POCP) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Trucking and courier services, except air
Blast furnaces and steel mills
Cement, hydraulic
Sanitary services, steam supply, and irrig...
Ready-mixed concrete
Miscellaneous repair shops
Crude petroleum and natural gas
Industrial inorganic and organic chemicals
Sawmills and planing mills, general
Total Accounted for in Top 10 M/P/S
Total Life Cycle POCP impacts
Remainder
POCP
(kgC4H4eq.)
11.11
9.44
4.66
4.47
3.53
1.96
1.94
1.93
1.89
1.76
42.69
84.96
42.27
Contribution to
Life Cycle POCP
13.07%
11.12%
5.49%
5.26%
4.15%
2.31%
2.28%
2.27%
2.22%
2.07%
50.25%
100.00%
49.75%
• Electric services (utilities)
• Trucking and courier services,
except air
• Blast furnaces and steel mills
• Cement, hydraulic
• Sanitary services, steam
supply, and irrigation systems
• Ready-mixed concrete
Miscellaneous repair shops
Crude petroleum and natural
gas
Industrial inorganic and
organic chemicals
Sawmills and planing mills,
general
Remainder
Acidification Potential (AP) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Cement, hydraulic
Blast furnaces and steel mills
Trucking and courier services, except air
Industrial inorganic and organic chemicals
Railroads and related services
Paper and paperboard mills
Crude petroleum and natural gas
Petroleum refining
Primary smelting and refining of copper
Total Accounted for in Top 10 M/P/S
Total Life Cycle AP impacts
Remainder
AP
(kgS02eq.)
206.62
65.14
26.93
19.89
13.93
13.60
13.30
10.29
10.25
9.08
389.03
502.36
113.33
Contribution to
Life Cycle AP
41.13%
12.97%
5.36%
3.96%
2.77%
2.71%
2.65%
2.05%
2.04%
1.81%
77.44%
100.00%
22.56%
• Electric services (utilities)
• Cement, hydraulic
• Blast furnaces and steel mills
• Trucking and courier services,
except air
• Industrial inorganic and
organic chemicals
• Railroads and related services
Paperand paperboard mills
Crude petroleum and natural
gas
Petroleum refining
Primary smelting and refining
of copper
Remainder
G-7
-------
APPENDIX Gl (CONTINUED)
Eutrophication Potential (EP) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Cement, hydraulic
Trucking and courier services, except air
Railroads and related services
Cotton
Miscellaneous crops
Natural gas transportation
Blast furnaces and steel mills
Industrial inorganic and organic chemicals
Ready-mixed concrete
Total Accounted for in Top 10 M/P/S
Total Life Cycle EP impacts
Remainder
EP
(kgP04eq.)
10.10
6.14
6.04
4.13
3.86
3.15
1.95
1.71
1.35
1.33
39.76
66.22
26.47
Contribution to
Life Cycle EP
15.26%
9.27%
9.12%
6.24%
5.83%
4.75%
2.94%
2.59%
2.04%
2.01%
60.04%
100.00%
39.96%
• Electric services (utilities)
• Cement, hydraulic
• Trucking and courier services,
except air
• Railroads and related services
• Cotton
Miscellaneous crops
Natural gas transportation
Blast furnaces and steel mills
Industrial inorganic and
organic chemicals
Ready-mixed concrete
Remainder
Energy Consumption (EC) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Blast furnaces and steel mills
Trucking and courier services, except air
Reconstituted wood products
Paper and paperboard mills
Wholesale trade
Sawmills and planing mills, general
Air transportation
Petroleum refining
Retail trade, except eating and drinking
Total Accounted for in Top 10 M/P/S
Total Life Cycle EC impacts
Remainder
EC(mBTU)
365.21
136.15
66.27
63.53
44.86
30.38
28.10
24.78
17.81
16.89
793.97
1,216.21
422.24
Contribution to
Life Cycle EC
30.03%
11.19%
5.45%
5.22%
3.69%
2.50%
2.31%
2.04%
1.46%
1.39%
65.28%
100.00%
34.72%
• Electric services (utilities)
• Blast furnaces and steel mills
• Trucking and courier services,
except air
• Reconstituted wood products
• Paper and paperboard mills
Wholesale trade
Sawmills and planing mills,
general
• Air transportation
Petroleum refining
Retail trade, except eating and
drinking
Remainder
G-8
-------
APPENDIX Gl (CONTINUED)
Water Consumption (WC) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Blast furnaces and steel mills
Industrial inorganic and organic chemicals
Sanitary services, steam supply, and irrig...
Paper and paperboard mills
Cotton
Petroleum refining
Sand and gravel
Agricultural, forestry, and fishery services
Iron and ferroalloy ores, and misc. metal...
Total Accounted for in Top 10 M/P/S
Total Life Cycle WC impacts
Remainder
WC
(103gal)
12,304.82
77.04
47.59
37.34
36.05
30.37
22.14
16.95
13.33
12.94
12,598.56
12,804.20
205.64
Contribution to
Life Cycle WC
96.10%
0.60%
0.37%
0.29%
0.28%
0.24%
0.17%
0.13%
0.10%
0.10%
98.39%
100.00%
1.61%
• Electric services (utilities)
• Blast furnaces and steel mills
• Industrial inorganic and organic
chemicals
• Sanitary services, steam supply,
and irrigation systems
• Paperand paperboard mills
• Cotton
Petroleum refining
Sand and gravel
Agricultural, forestry, and
fishery services
Iron and ferroalloy ores, and
miscellaneous metal ores, n.e.c.
Remainder
Material Input (MTL) - Output Contribution Analysis - Pre-Occupancv Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Sand and gravel
Dimension, crushed and broken stone
Forestry products
Cement, hydraulic
Coal
Petroleum refining
Iron and ferroalloy ores, and misc. metal...
New office, industrial and commercial bldg...
Sawmills and planing mills, general
Asphalt paving mixtures and blocks
Total Accounted for in Top 10 M/P/S
Total Life Cycle MTL impacts
Remainder
MTL
(mton)
1,086.83
929.88
102.95
82.99
68.52
42.38
30.14
28.46
27.86
26.99
2,427.00
2,668.70
241.69
Contribution to
Life Cycle MTL
40.73%
34.84%
3.86%
3.11%
2.57%
1.59%
1.13%
1.07%
1.04%
1.01%
90.94%
100.00%
9.06%
• Sand and gravel
• Dimension, crushed and broken
stone
• Forestry products
• Cement, hydraulic
• Coal
Petroleum refining
Iron and ferroalloy ores, and
miscellaneous metal ores, n.e.c.
New office, industrial and
commercial buildings construction
Sawmills and planing mills,
general
Asphalt paving mixtures and
blocks
Remainder
G-9
-------
APPENDIX Gl (CONTINUED)
Waste (WST) - Output Contribution Analysis - Pre-Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Coal
Forestry products
Sand and gravel
Petroleum refining
Crude petroleum and natural gas
Industrial inorganic and organic chemicals
Natural gas distribution
Lime
Iron and ferroalloy ores, and misc. metal...
Clay, ceramic, and refractory minerals
Total Accounted for in Top 10 M/P/S
Total Life Cycle WST impacts
Remainder
WST
(mton)
22.35
19.67
18.85
17.22
8.79
5.11
4.96
2.59
2.48
2.25
104.28
117.95
13.67
Contribution to
Life Cycle WST
18.95%
16.68%
15.98%
14.60%
7.45%
4.33%
4.21%
2.19%
2.10%
1.91%
88.41%
100.00%
11.59%
• Coal
• Forestry products
• Sand and gravel
• Petroleum refining
• Crude petroleum and natural gas
• Industrial inorganic and organic
chemicals
• Natural gas distribution
• Lime
Iron and ferroalloy ores, and
miscellaneous metal ores, n.e.c.
Clay, ceramic, and refractory
minerals
Remainder
G-10
-------
APPENDIX G2 -VECTOR ANALYSIS RESULTS, OUTPUT CONTRIBUTION BASIS, PRE-OCCUPANCY PHASE
All Impacts
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Cotton
Brick and structural clay tile
Trucking and courier services, except air
Sand and gravel
Crude petroleum and natural gas
Mineral wool
Coal
Industrial inorganic and organic chemicals
Dimension, crushed and broken stone
Number of Standard Deviations from the Mean
Q.
O
<
-007
-007
-007
-007
-007
17 OP
-007
12.42
-004
-OOfi
o
_i
-014
444
-014
133?
-014
-014
-014
-014
-014
-014
0
17??
-OOP
048
384
045
?S4
1?fi
07P
095
051
Q_
0
O
-01?
-013
-013
-01?
-01?
-01?
17 ?7
-013
1001
-013
Q_
1—
5P5
-011
10 ?1
005
015
-011
085
04P
fi45
-0??
LU
<
L_l_
01?
?047
-004
-010
-010
-OOP
004
01P
1 01
-010
LU
<
880
-OOP
1870
-OOP
-OOP
-OOP
-007
035
041
-OOP
i—
LU
1—
0??
1P33
-OOP
-013
-013
-011
0??
03?
?44
-013
LU
to
LL.
S7P
-010
18 fi?
-010
-OOP
-OOP
-004
038
07?
-010
LU
to
S
-018
005
-01P
-01P
-01P
-008
13P
-01P
1018
-01P
o
o
Q_
1348
-017
OOP
1143
-004
?15
147
034
?10
010
Q_
<
1P74
-011
-OOfi
1 80
-OOP
088
001
-010
1 ?3
-OOfi
Q.
LU
13Sfi
517
-001
a?i
-011
1 58
031
-015
1 fi7
-001
o
LU
18 P4
-013
OOP
33?
04P
018
0?8
-007
003
04P
o
?1 17
000
-005
-003
-00?
-003
-004
-005
003
-004
_i
i—
-008
-008
-OOP
-OOP
15Pfi
0?5
-OOP
OP?
01fi
13fi4
i—
to
-014
-011
-014
-014
Pfi4
44?
-014
1145
?51
000
Vector
Magnitude
45.35
28.97
28.30
20.11
18.66
18.10
17.46
16.97
16.40
13.66
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Cotton
Brick and structural clay tile
Trucking and courier services, except air
Sand and gravel
Crude petroleum and natural gas
Mineral wool
Coal
Industrial inorganic and organic chemicals
Dimension, crushed and broken stone
Factor Influence (change in vector orientation, in degrees)
Q.
Q
<
0
0
0
0
0
71
0
47
0
0
o
_i
0
9
0
41
0
0
0
0
0
-1
Q_
0
22
0
1
11
1
9
4
3
3
2
Q.
Q
0
0
0
0
0
0
0
81
0
38
-1
Q_
1—
8
0
21
0
0
0
3
2
23
-1
LU
<
l_l_
0
45
0
0
0
0
0
1
4
0
LU
<
S
11
0
41
0
0
0
0
1
1
0
i—
LU
1—
0
42
0
0
0
0
1
1
9
-1
LU
to
LL.
11
0
41
0
0
0
0
1
3
0
LU
to
0
0
0
-1
-1
0
5
-1
38
-1
o
0
Q_
17
0
0
35
0
7
5
1
7
0
£
26
0
0
5
0
3
0
0
4
0
Q_
LU
18
10
0
24
0
5
1
-1
6
0
o
LU
25
0
0
10
2
1
1
0
0
2
o
28
0
0
0
0
0
0
0
0
0
_i
i—
0
0
0
0
59
1
0
3
1
87
i—
0
0
0
0
31
14
0
42
9
0
G-ll
-------
APPENDIX G2 (CONTINUED)
Natural Resources and Land Use Impact Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Sand and gravel
Crude petroleum and natural gas
Coal
Trucking and courier services, except air
Dimension, crushed and broken stone
Forestry products
Petroleum refining
Meat animals
Blast furnaces and steel mills
Number of Standard Deviations from the Mean
Q_
0
<
-0.07
-0.07
17.09
12.42
-0.07
-0.06
-0.07
0.83
-0.07
-0.07
o
^
_i
-0.14
-0.14
-0.14
-0.14
13.32
-0.14
3.12
-0.14
7.51
-0.14
o
LU
18.94
0.49
0.18
-0.07
3.32
0.49
0.01
0.79
-0.14
6.97
o
21.17
-0.02
-0.03
-0.05
-0.03
-0.04
-0.05
-0.01
-0.05
0.08
_i
i—
-0.08
15.96
0.25
0.92
-0.09
13.64
1.43
0.54
-0.09
-0.01
i—
to
-0.14
9.64
4.42
11.45
-0.14
0.00
10.07
8.79
-0.12
-0.14
Vector
Magnitude
28.40
18.65
17.65
16.92
13.73
13.65
10.64
8.89
7.51
6.98
Factor Influence (change in
vector orientation, in degrees)
Q_
0
<
0
0
75
47
0
0
0
5
-1
-1
o
^
_i
0
0
0
0
76
-1
17
-1
88
-1
o
LU
42
2
1
0
14
2
0
5
-1
88
o
48
0
0
0
0
0
0
0
0
1
_i
i—
0
59
1
3
0
88
8
3
-1
0
6
0
31
15
43
-1
0
71
82
-1
-1
Toxicitv Impact Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Brick and structural clay tile
Cotton
Electric services (utilities)
Paper and paperboard mills
Industrial inorganic and organic chemicals
Pulp mills
Primary aluminum
Copper ore
Plastics materials and resins
Primary smelting and refining of copper
Number of Standard Deviations from
the Mean
Q_
h-
10.21
-0.11
5.95
5.91
6.45
5.09
5.22
6.78
4.61
5.34
Q_
1—
LU
<
l_l_
-0.04
20.47
0.12
0.95
1.01
0.84
0.45
1.88
0.79
0.73
Q.
1—
LU
<
18.70
-0.09
8.80
0.33
0.41
0.18
3.97
0.17
0.39
0.02
Q.
1—
LU
h-
-0.09
19.33
0.22
2.51
2.44
2.24
1.14
4.57
1.74
1.89
Q.
1—
LU
to
LL.
18.62
-0.10
8.79
0.65
0.72
0.46
4.10
0.57
0.65
0.18
Q_
1—
LU
to
-0.19
0.05
-0.18
10.70
10.18
9.62
4.06
-0.16
6.53
-0.17
Vector
Magnitude
28.30
28.15
13.79
12.54
12.37
11.15
8.82
8.42
8.25
5.71
Factor Influence (change in vector
orientation, in degrees)
Q_
h-
21
0
26
28
31
27
36
54
34
69
Q_
1—
LU
<
l_l_
0
47
0
4
5
4
3
13
5
7
Q.
1—
LU
<
S
41
0
40
1
2
1
27
1
3
0
Q.
1—
LU
h-
0
43
1
12
11
12
7
33
12
19
Q.
1—
LU
to
LL.
41
0
40
3
3
2
28
4
5
2
Q_
1—
LU
0
0
-1
59
55
60
27
-1
52
-2
G-12
-------
APPENDIX G2 (CONTINUED)
Pollution Impacts Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Mineral wool
Trucking and courier services, except air
Cement, hydraulic
Industrial inorganic and organic chemicals
Blast furnaces and steel mills
Railroads and related services
Sanitary services, steam supply, and irrigation...
Cotton
Miscellaneous crops
Number of Standard Deviations from
the Mean
o
17.22
1.26
3.84
6.68
0.95
6.78
0.52
3.31
-0.09
-0.17
Q_
0
o
-0.12
17.27
-0.12
-0.12
10.01
-0.11
-0.13
-0.11
-0.13
-0.13
Q_
O
o
Q.
13.48
1.47
11.43
5.29
2.10
5.52
1.09
4.12
-0.17
-0.22
Q_
<
19.74
0.01
1.80
6.15
1.23
2.48
1.20
0.36
-0.11
-0.11
Q.
LU
13.86
0.31
8.21
8.34
1.67
2.18
5.55
1.06
5.17
4.17
Vector
Magnitude
32.56
17.38
14.70
13.41
10.48
9.35
5.80
5.40
5.17
4.19
Factor Influence (change in vector
orientation, in degrees)
o
32
4
15
30
5
46
5
38
-1
-2
Q_
0
O
0
84
0
-1
73
-1
-1
-1
-1
-2
Q_
O
O
Q.
24
5
51
23
12
36
11
50
-2
-3
Q_
<
37
0
7
27
7
15
12
4
-1
-1
Q.
LU
25
1
34
38
9
13
73
11
87
86
G-13
-------
APPENDIX G3 - OCCUPANCY-PHASE RESULTS BY IMPACT CATEGORY
Abiotic Depletion Potential (ADP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Crude petroleum and natural gas
Coal
Petroleum refining
Industrial inorganic and organic chemicals
Explosives
Dimension, crushed and broken stone
Copper ore
Iron and ferroalloy ores, and misc. metal...
Nonmetallic mineral services and misc.
Nonferrous metal ores, except copper
Total Accounted for in Top 10 M/P/S
Total Life Cycle ADP impacts
Remainder
ADP
(kgSn eq.)
2,361.74
2,238.20
50.54
0.65
0.21
0.02
0.00
0.00
0.00
0.00
4,651.36
4,651.36
0.00
Contribution to
Life Cycle ADP
50.78%
48.12%
1.09%
0.01%
0.00%
0.00%
0.00%
0.00%
0.00%
0.00%
100.00%
100.00%
0.00%
• Crude petroleum and natural
gas
• Coal
• Petroleum refining
• Industrial inorganic and organic
chemicals
• Explosives
• Dimension, crushed and broken
stone
Copper ore
Iron and ferroalloy ores, and
miscellaneous metal ores, n.e.c.
Nonmetallic mineral services
and miscellaneous
Nonferrous metal ores, except
copper
Remainder
Land Use Competition (LUC) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Cotton
Agricultural, forestry, and fishery services
Miscellaneous livestock
Poultry and eggs
Meat animals
Food grains
Trucking and courier services, except air
Miscellaneous crops
Forestry products
Dairy farm products
Total Accounted for in Top 10 M/P/S
Total Life Cycle LUC impacts
Remainder
LUC
(m2*yr)
3,591.56
3,005.84
2,836.48
2,741.37
2,570.39
2,469.93
2,415.68
1,838.66
1,564.98
881.72
23,916.62
24,601.79
685.17
Contribution to
Life Cycle LUC
14.60%
12.22%
11.53%
11.14%
10.45%
10.04%
9.82%
7.47%
6.36%
3.58%
97.21%
100.00%
2.79%
• Cotton
• Agricultural, forestry, and
fishery services
• Miscellaneous livestock
• Poultry and eggs
• Meat animals
Food grains
• Trucking and courier services,
except air
Miscellaneous crops
Forestry products
• Dairy farm products
Remainder
G-14
-------
APPENDIX G3 (CONTINUED)
Global Warming Potential (GWP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Crude petroleum and natural gas
Coal
Blast furnaces and steel mills
Petroleum refining
Household appliances, n.e.c.
Sanitary services, steam supply, and irrig...
Trucking and courier services, except air
Mineral wool
Gypsum products
Total Accounted for in Top 10 M/P/S
Total Life Cycle GWP impacts
Remainder
GWP
(kgC02eq.)
576,357.80
41,204.78
17,305.55
17,086.43
8,728.37
5,638.15
5,207.66
4,993.35
4,143.56
3,824.58
684,490.23
758,781.76
74,291.53
Contribution to
Life Cycle GWP
75.96%
5.43%
2.28%
2.25%
1.15%
0.74%
0.69%
0.66%
0.55%
0.50%
90.21%
100.00%
9.79%
• Electric services (utilities)
• Crude petroleum and natural
gas
• Coal
• Blast furnaces and steel mills
• Petroleum refining
• Household appliances, n.e.c.
Sanitary services, steam
supply, and irrigation systems
Trucking and courier services,
except air
Mineral wool
Gypsum products
Remainder
Stratospheric Ozone Depletion Potential (OOP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Mineral wool
Industrial inorganic and organic chemicals
Household appliances, n.e.c.
Primary aluminum
Plastics materials and resins
Synthetic rubber
Primary nonferrous metals, n.e.c.
Miscellaneous plastics products, n.e.c.
Miscellaneous repair shops
Metal doors, sash, frames, molding, and trim
Total Accounted for in Top 10 M/P/S
Total Life Cycle OOP impacts
Remainder
OOP
(gCFC-lleq.)
337.05
191.25
163.55
85.82
60.82
34.42
27.47
24.49
22.57
14.36
961.79
1,138.08
176.29
Contribution to
Life Cycle OOP
29.62%
16.80%
14.37%
7.54%
5.34%
3.02%
2.41%
2.15%
1.98%
1.26%
84.51%
100.00%
15.49%
• Mineral wool
• Industrial inorganic and
organic chemicals
• Household appliances, n.e.c.
• Primary aluminum
• Plastics materials and resins
• Synthetic rubber
Primary nonferrous metals,
n.e.c.
• Miscellaneous plastics
products, n.e.c.
Miscellaneous repair shops
Metal doors, sash, frames,
molding, and trim
Remainder
G-15
-------
APPENDIX G3 (CONTINUED)
Human Toxicity Potential (HTP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Primary aluminum
Industrial inorganic and organic chemicals
Plastics materials and resins
Copper ore
Paper and paperboard mills
Coal
Pulp mills
Primary smelting and refining of copper
Nonmetallic mineral products, n.e.c.
Total Accounted for in Top 10 M/P/S
Total Life Cycle HTP impacts
Remainder
HTP
(kg p-DCB eq.)
19,183.45
1,773.02
1,752.57
1,388.53
1,333.96
1,302.82
1,196.65
979.22
931.22
808.05
30,649.50
38,712.02
8,062.52
Contribution to
Life Cycle HTP
49.55%
4.58%
4.53%
3.59%
3.45%
3.37%
3.09%
2.53%
2.41%
2.09%
79.17%
100.00%
20.83%
• Electric services (utilities)
• Primary aluminum
• Industrial inorganic and
organic chemicals
• Plastics materials and resins
• Copper ore
• Paper and paperboard mills
Coal
Pulp mills
Primary smelting and refining
of copper
Nonmetallic mineral products,
n.e.c.
Remainder
Freshwater Aquatic Ecotoxicitv Potential (FAETP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Cotton
Miscellaneous crops
Electric services (utilities)
Agricultural, forestry, and fishery services
Coal
Copper ore
Sanitary services, steam supply, and irrig...
Industrial inorganic and organic chemicals
Plastics materials and resins
Paper and paperboard mills
Total Accounted for in Top 10 M/P/S
Total Life Cycle FAETP impacts
Remainder
FAETP
(kg p-DCB eq.)
3,457.51
329.51
220.04
190.24
157.21
124.09
104.74
95.68
84.08
73.64
4,836.77
5,482.93
646.17
Contribution to
Life Cycle FAETP
63.06%
6.01%
4.01%
3.47%
2.87%
2.26%
1.91%
1.75%
1.53%
1.34%
88.21%
100.00%
11.79%
Cotton
Miscellaneous crops
Electric services (utilities)
Agricultural, forestry, and
fishery services
Coal
Copper ore
Sanitary services, steam
supply, and irrigation systems
Industrial inorganic and
organic chemicals
Plastics materials and resins
Paper and paperboard mills
Remainder
G-16
-------
APPENDIX G3 (CONTINUED)
Marine Aquatic Ecotoxicity Potential (MAETP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Primary aluminum
Coal
Brick and structural clay tile
Plastics materials and resins
Industrial inorganic and organic chemicals
Glass and glass products, except containers
Paper and paperboard mills
Manmade organic fibers, except cellulosic
Sanitary services, steam supply, and irrig...
Total Accounted for in Top 10 M/P/S
Total Life Cycle MAETP impacts
Remainder
MAETP
(mton p-DCB eq.)
218,884.87
10,464.55
5,834.30
1,516.88
1,086.92
1,039.04
860.43
695.57
633.97
605.55
241,622.08
246,592.22
4,970.13
Contribution to
Life Cycle MAETP
88.76%
4.24%
2.37%
0.62%
0.44%
0.42%
0.35%
0.28%
0.26%
0.25%
97.98%
100.00%
2.02%
• Electric services (utilities)
• Primary aluminum
• Coal
• Brick and structural clay tile
• Plastics materials and resins
• Industrial inorganic and
organic chemicals
Glass and glass products,
except containers
Paper and paperboard mills
Manmade organic fibers,
except cellulosic
• Sanitary services, steam
supply, and irrigation systems
Remainder
Terrestrial Ecotoxicitv Potential (TETP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Cotton
Electric services (utilities)
Copper ore
Miscellaneous crops
Coal
Industrial inorganic and organic chemicals
Paper and paperboard mills
Plastics materials and resins
Agricultural, forestry, and fishery services
Pulp mills
Total Accounted for in Top 10 M/P/S
Total Life Cycle TETP impacts
Remainder
TETP
(kg p-DCB eq.)
3,043.21
341.28
275.27
259.69
234.84
207.98
172.38
165.45
162.80
134.67
4,997.58
6,252.11
1,254.52
Contribution to
Life Cycle TETP
48.68%
5.46%
4.40%
4.15%
3.76%
3.33%
2.76%
2.65%
2.60%
2.15%
79.93%
100.00%
20.07%
• Cotton
• Electric services (utilities)
Copper ore
• Miscellaneous crops
• Coal
• Industrial inorganic and
organic chemicals
Paper and paperboard mills
Plastics materials and resins
Agricultural, forestry, and
fishery services
Pulp mills
Remainder
G-17
-------
APPENDIX G3 (CONTINUED)
Freshwater Sediment Ecotoxicity Potential (FSETP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Primary aluminum
Coal
Industrial inorganic and organic chemicals
Plastics materials and resins
Brick and structural clay tile
Paper and paperboard mills
Copper ore
Glass and glass products, except containers
Manmade organic fibers, except cellulosic
Total Accounted for in Top 10 M/P/S
Total Life Cycle FSETP impacts
Remainder
FSETP
(mton p-DCB eq.)
72,378.80
3,578.54
2,065.95
562.75
561.11
499.39
415.03
333.55
301.46
285.38
80,981.97
83,747.98
2,766.01
Contribution to
Life Cycle FSETP
86.42%
4.27%
2.47%
0.67%
0.67%
0.60%
0.50%
0.40%
0.36%
0.34%
96.70%
100.00%
3.30%
• Electric services (utilities)
• Primary aluminum
• Coal
• Industrial inorganic and
organic chemicals
• Plastics materials and resins
• Brick and structural clay tile
Paper and paperboard mills
Copper ore
Glass and glass products,
except containers
Manmade organic fibers,
except cellulosic
Remainder
Marine Sediment Ecotoxicitv Potential (MSETP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Industrial inorganic and organic chemicals
Paper and paperboard mills
Plastics materials and resins
Pulp mills
Primary aluminum
Synthetic rubber
Gum and wood chemicals
Photographic equipment and supplies
Primary nonferrous metals, n.e.c.
Mineral wool
Total Accounted for in Top 10 M/P/S
Total Life Cycle MSETP impacts
Remainder
MSETP
(kg p-DCB eq.)
6,328.72
5,366.14
4,485.17
4,197.51
3,216.81
1,600.71
1,413.42
1,137.86
1,036.62
990.39
29,773.35
41,601.17
11,827.82
Contribution to
Life Cycle MSETP
15.21%
12.90%
10.78%
10.09%
7.73%
3.85%
3.40%
2.74%
2.49%
2.38%
71.57%
100.00%
28.43%
• Industrial inorganic and
organic chemicals
• Paper and paperboard mills
Plastics materials and resins
• Pulp mills
• Primary aluminum
• Synthetic rubber
• Gum and wood chemicals
Photographic equipment and
supplies
Primary nonferrous metals,
n.e.c.
Mineral wool
Remainder
G-18
-------
APPENDIX G3 (CONTINUED)
Photochemical Ozone Creation Potential (POCP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Crude petroleum and natural gas
Trucking and courier services, except air
Blast furnaces and steel mills
Natural gas transportation
Coal
Household appliances, n.e.c.
Sawmills and planing mills, general
Miscellaneous plastics products, n.e.c.
Petroleum refining
Total Accounted for in Top 10 M/P/S
Total Life Cycle POCP impacts
Remainder
POCP
(kgC4H4eq.)
167.38
11.97
5.33
5.20
4.31
3.72
3.43
3.37
2.48
2.47
209.67
253.35
43.68
Contribution to
Life Cycle POCP
66.07%
4.72%
2.10%
2.05%
1.70%
1.47%
1.35%
1.33%
0.98%
0.97%
82.76%
100.00%
17.24%
• Electric services (utilities)
• Crude petroleum and natural
gas
• Trucking and courier services,
except air
• Blast furnaces and steel mills
• Natural gas transportation
• Coal
Household appliances, n.e.c.
Sawmills and planing mills,
general
Miscellaneous plastics
products, n.e.c.
Petroleum refining
Remainder
Acidification Potential (AP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Crude petroleum and natural gas
Natural gas transportation
Blast furnaces and steel mills
Petroleum refining
Railroads and related services
Industrial inorganic and organic chemicals
Primary aluminum
Paper and paperboard mills
Trucking and courier services, except air
Total Accounted for in Top 10 M/P/S
Total Life Cycle AP impacts
Remainder
AP
(kgS02eq.)
4,494.91
92.21
70.08
43.40
37.73
34.65
25.62
19.85
19.75
16.21
4,854.41
5,022.33
167.92
Contribution to
Life Cycle AP
89.50%
1.84%
1.40%
0.86%
0.75%
0.69%
0.51%
0.40%
0.39%
0.32%
96.66%
100.00%
3.34%
• Electric services (utilities)
• Crude petroleum and natural
gas
• Natural gas transportation
• Blast furnaces and steel mills
• Petroleum refining
• Railroads and related services
• Industrial inorganic and
organic chemicals
Primary aluminum
Paper and paperboard mills
• Trucking and courier services,
except air
Remainder
G-19
-------
APPENDIX G3 (CONTINUED)
Eutrophication Potential (EP) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Natural gas transportation
Cotton
Crude petroleum and natural gas
Railroads and related services
Miscellaneous crops
Trucking and courier services, except air
Sawmills and planing mills, general
Household appliances, n.e.c.
Blast furnaces and steel mills
Total Accounted for in Top 10 M/P/S
Total Life Cycle EP impacts
Remainder
EP
(kgP04eq.)
161.49
15.64
10.10
8.45
7.74
5.03
3.62
2.49
2.04
2.03
218.63
247.40
28.78
Contribution to
Life Cycle EP
65.28%
6.32%
4.08%
3.41%
3.13%
2.03%
1.46%
1.01%
0.83%
0.82%
88.37%
100.00%
11.63%
• Electric services (utilities)
• Natural gas transportation
• Cotton
• Crude petroleum and natural
gas
• Railroads and related services
• Miscellaneous crops
Trucking and courier services,
except air
Sawmills and planing mills,
general
Household appliances, n.e.c.
Blast furnaces and steel mills
Remainder
Energy Consumption (EC) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Blast furnaces and steel mills
Petrol., natural gas, and solid min. explor...
Household appliances, n.e.c.
Asphalt felts and coatings
Sawmills and planing mills, general
Hardwood dimension and flooring mills
Paper and paperboard mills
Petroleum refining
Crude petroleum and natural gas
Total Accounted for in Top 10 M/P/S
Total Life Cycle EC impacts
Remainder
EC
(mBTU)
11,618.99
320.93
208.46
194.97
113.98
113.74
100.29
97.45
95.89
80.24
12,944.92
13,783.16
838.23
Contribution to
Life Cycle EC
84.30%
2.33%
1.51%
1.41%
0.83%
0.83%
0.73%
0.71%
0.70%
0.58%
93.92%
100.00%
6.08%
• Electric services (utilities)
• Blast furnaces and steel mills
• Petroleum, natural gas, and
solid mineral exploration
• Household appliances, n.e.c.
• Asphalt felts and coatings
• Sawmills and planing mills,
general
Hardwood dimension and
flooring mills
Paper and paperboard mills
Petroleum refining
• Crude petroleum and natural
gas
Remainder
G-20
-------
APPENDIX G3 (CONTINUED)
Water Consumption (WC) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Electric services (utilities)
Blast furnaces and steel mills
Crude petroleum and natural gas
Cotton
Industrial inorganic and organic chemicals
Petroleum refining
Paper and paperboard mills
Sanitary services, steam supply, and irrig...
Agricultural, forestry, and fishery services
Sawmills and planing mills, general
Total Accounted for in Top 10 M/P/S
Total Life Cycle WC impacts
Remainder
WC
(103gal)
252,935.22
117.33
102.99
102.23
82.69
77.02
50.59
34.54
25.49
23.72
253,551.82
253,807.60
255.78
Contribution to
Life Cycle WC
99.66%
0.05%
0.04%
0.04%
0.03%
0.03%
0.02%
0.01%
0.01%
0.01%
99.90%
100.00%
0.10%
• Electric services (utilities)
• Blast furnaces and steel mills
• Crude petroleum and natural
gas
• Cotton
• Industrial inorganic and
organic chemicals
Petroleum refining
Paper and paperboard mills
Sanitary services, steam
supply, and irrigation systems
Agricultural, forestry, and
fishery services
Sawmills and planing mills,
general
Remainder
Material Input (MTL) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Coal
Natural gas distribution
Forestry products
Crude petroleum and natural gas
Sand and gravel
Petroleum refining
Dimension, crushed and broken stone
New office, industrial and commercial bldg
Sawmills and planing mills, general
Hardwood dimension and flooring mills
Total Accounted for in Top 10 M/P/S
Total Life Cycle MTL impacts
Remainder
MTL
(mton)
322.92
109.85
90.72
82.82
74.19
63.05
45.46
43.29
31.16
27.21
890.69
1,049.69
159.01
Contribution to
Life Cycle MTL
30.76%
10.47%
8.64%
7.89%
7.07%
6.01%
4.33%
4.12%
2.97%
2.59%
84.85%
100.00%
15.15%
• Coal
• Natural gas distribution
• Forestry products
• Crude petroleum and natural gas
• Sand and gravel
Petroleum refining
Dimension, crushed and broken
stone
New office, industrial and
commercial buildings construction
Sawmills and planing mills,
general
Hardwood dimension and flooring
mills
Remainder
G-21
-------
APPENDIX G3 (CONTINUED)
Waste (WST) - Output Contribution Analysis - Occupancy Phase
Rank
1
2
3
4
5
6
7
8
9
10
BEA Material/Product/Service Description
Coal
Natural gas distribution
Crude petroleum and natural gas
Petroleum refining
Forestry products
Hardwood dimension and flooring mills
Industrial inorganic and organic chemicals
Asphalt felts and coatings
Plastics materials and resins
Iron and ferroalloy ores, and misc. metal...
Total Accounted for in Top 10 M/P/S
Total Life Cycle WST impacts
Remainder
WST
(mton)
263.43
105.58
79.62
64.09
43.36
22.54
9.50
5.06
4.37
3.81
601.36
623.03
21.67
Contribution to
Life Cycle WST
42.28%
16.95%
12.78%
10.29%
6.96%
3.62%
1.52%
0.81%
0.70%
0.61%
96.52%
100.00%
3.48%
• Coal
• Natural gas distribution
• Crude petroleum and natural gas
• Petroleum refining
• Forestry products
• Hardwood dimension and flooring
mills
• Industrial inorganic and organic
chemicals
Asphalt felts and coatings
Plastics materials and resins
Iron and ferroalloy ores, and
miscellaneous metal ores, n.e.c.
Remainder
G-22
-------
APPENDIX G4 -VECTOR ANALYSIS RESULTS, OUTPUT CONTRIBUTION BASIS, OCCUPANCY PHASE
All Impacts
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Cotton
Coal
Crude petroleum and natural gas
Mineral wool
Industrial inorganic and organic chemicals
Paper and paperboard mills
Natural gas distribution
Plastics materials and resins
Agricultural, forestry, and fishery services
Number of Standard Deviations from the Mean
Q.
O
<
-007
-007
1454
1535
-007
-OOfi
-007
-007
-007
-007
o
_i
-015
P57
-015
-015
-015
-015
-015
-015
-015
7 PR
0
?10P
-004
057
145
OOP
OOfi
001
-003
003
-005
Q_
0
O
-010
-01?
-01?
-011
1fi?P
P1P
-OOP
-01?
?84
-01?
Q_
1—
?070
-003
1?0
008
0??
181
13?
-003
141
-008
Q_
1—
LU
<
L_l_
1?fi
?OP3
088
-005
000
051
037
-OOfi
044
108
Q.
1—
LU
<
?1 13
-005
051
-005
-005
005
001
-005
005
-005
Q.
1—
LU
1—
??3
?OfiO
150
-003
011
13?
108
-004
103
101
Q.
1—
LU
to
LL.
?1 13
-005
055
-005
-004
011
007
-005
011
-005
Q_
1—
LU
to
-011
03fi
-015
044
170
1181
PPP
031
83?
-015
Q.
O
0
Q_
?105
-OOfi
040
144
01fi
0?3
010
-001
014
-005
Q_
<
?1 1fi
-005
-005
038
-004
007
004
-003
-001
-005
Q_
LU
?OP5
1?4
-003
103
000
017
007
003
003
008
o
LU
?1 15
-005
-001
OOP
-001
-004
01?
-00?
-00?
-005
£
?1 17
-004
-005
-004
-005
-004
-004
-005
-005
-005
_i
i—
0.21
-011
1778
44fi
-013
058
-011
5Pfi
011
-OOP
i—
to
-010
-008
18 ?4
544
-010
05fi
-008
7?5
0.21
-OOP
Vector
Magnitude
63.23
30.P1
2P.42
17.05
16.38
15.16
10.14
P.40
8.P8
8.12
Rank
1
2
3
4
5
6
7
8
P
10
Description
Electric services (utilities)
Cotton
Coal
Crude petroleum and natural gas
Mineral wool
Industrial inorganic and organic chemicals
Paper and paperboard mills
Natural gas distribution
Plastics materials and resins
Agricultural, forestry, and fishery services
Factor Influence (change in vector orientation, in degrees)
Q_
0
<
0
0
30
64
0
0
0
0
0
0
o
^
_i
0
18
0
0
-1
-1
-1
-1
-1
7P
Q_
0
19
0
1
5
0
0
0
0
0
0
Q.
Q
0
0
0
0
0
84
37
0
-1
18
-1
Q_
h-
19
0
2
0
1
7
7
0
9
-1
LU
<
LL.
1
43
2
0
0
2
2
0
3
8
LU
<
S
20
0
1
0
0
0
0
0
0
0
i—
LU
h-
2
42
3
0
0
5
6
0
7
7
LU
to
l_l_
20
0
1
0
0
0
0
0
1
0
LU
to
0
1
0
1
6
51
80
2
68
-1
o
0
Q.
19
0
1
5
1
1
1
0
1
0
£
20
0
0
1
0
0
0
0
0
0
Q_
LU
19
2
0
3
0
1
0
0
0
1
o
LU
20
0
0
0
0
0
1
0
0
0
£
20
0
0
0
0
0
0
0
0
0
_l
0
0
37
15
0
2
-1
39
1
-1
i—
0
0
38
19
0
2
0
51
1
-1
G-23
-------
APPENDIX G4 (CONTINUED)
Natural Resources and Land Use Impact Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Coal
Crude petroleum and natural gas
Cotton
Natural gas distribution
Agricultural, forestry, and fishery services
Miscellaneous livestock
Poultry and eggs
Forestry products
Meat animals
Number of Standard Deviations from the Mean
Q_
0
<
-0.07
14.54
15.35
-0.07
-0.07
-0.07
-0.07
-0.07
-0.07
-0.07
o
^
_i
-0.15
-0.15
-0.15
9.57
-0.15
7.98
7.52
7.27
4.09
6.80
o
LU
21.15
-0.01
0.09
-0.05
-0.02
-0.05
-0.06
-0.06
-0.04
-0.06
o
21.17
-0.05
-0.04
-0.04
-0.05
-0.05
-0.05
-0.05
-0.05
-0.05
_i
i—
0.21
17.78
4.46
-0.11
5.96
-0.09
-0.13
-0.13
4.90
-0.12
i—
co
-0.10
18.24
5.44
-0.08
7.25
-0.09
-0.10
-0.10
2.92
-0.09
Vector
Magnitude
29.92
29.33
16.88
9.57
9.39
7.98
7.53
7.27
7.02
6.81
Factor Influence (change in
vector orientation, in degrees)
Q_
0
<
0
30
65
0
0
0
-1
-1
-1
-1
o
^
_i
0
0
-1
89
-1
89
89
89
36
88
o
LU
45
0
0
0
0
0
0
0
0
0
o
45
0
0
0
0
0
0
0
0
0
_i
i—
0
37
15
-1
39
-1
-1
-1
44
-1
6
0
38
19
-1
51
-1
-1
-1
25
-1
Toxicitv Impact Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Cotton
Industrial inorganic and organic chemicals
Paper and paperboard mills
Plastics materials and resins
Pulp mills
Primary aluminum
Synthetic rubber
Miscellaneous crops
Gum and wood chemicals
Number of Standard Deviations from
the Mean
Q.
1—
I
20.70
-0.03
1.81
1.32
1.41
0.97
1.83
0.38
-0.05
0.26
Q_
1—
LU
<
LL.
1.26
20.93
0.51
0.37
0.44
0.27
0.28
0.07
1.93
0.04
Q_
1—
LU
<
21.13
-0.05
0.05
0.01
0.05
-0.02
0.96
-0.04
-0.05
-0.04
Q_
1—
LU
h-
2.23
20.60
1.32
1.08
1.03
0.82
0.77
0.26
1.67
0.20
Q_
1—
LU
CO
l_l_
21.13
-0.05
0.11
0.07
0.11
0.02
0.99
-0.02
-0.05
-0.03
Q.
1—
LU
CO
-0.11
0.36
11.81
9.99
8.32
7.77
5.92
2.86
-0.15
2.50
Vector
Magnitude
36.44
29.37
12.03
10.14
8.51
7.88
6.40
2.89
2.56
2.52
Factor Influence (change in vector
orientation, in degrees)
Q.
1—
I
35
0
9
7
10
7
17
7
-1
6
Q_
1—
LU
<
LL.
2
45
2
2
3
2
3
1
49
1
Q_
1—
LU
35
0
0
0
0
0
9
-1
-1
-1
Q_
1—
LU
h-
4
45
6
6
7
6
7
5
41
5
Q_
1—
LU
CO
l_l_
35
0
1
0
1
0
9
0
-1
-1
Q.
1—
LU
CO
0
1
79
80
78
81
68
81
-3
82
G-24
-------
APPENDIX G4 (CONTINUED)
Pollution Impacts Grouping
Rank
1
2
3
4
5
6
7
8
9
10
Description
Electric services (utilities)
Mineral wool
Industrial inorganic and organic chemicals
Household appliances, n.e.c.
Primary aluminum
Plastics materials and resins
Crude petroleum and natural gas
Natural gas transportation
Synthetic rubber
Cotton
Number of Standard Deviations from the
Mean
Q.
O
21.09
0.09
0.06
0.15
-0.01
0.03
1.45
-0.05
-0.05
-0.04
Q_
0
O
-0.10
16.29
9.19
7.84
4.06
2.84
-0.11
-0.12
1.55
-0.12
Q_
O
o
Q_
21.05
0.16
0.23
0.36
0.22
0.14
1.44
0.47
-0.05
-0.06
Q_
<
21.16
-0.04
0.07
-0.01
0.04
-0.01
0.38
0.28
-0.05
-0.05
Q.
LU
20.95
0.00
0.17
0.19
0.01
0.03
1.03
1.96
-0.07
1.24
Vector
Magnitude
42.12
16.29
9.19
7.85
4.06
2.84
2.32
2.04
1.56
1.25
Factor Influence (change in vector
orientation, in degrees)
o
30
0
0
1
0
1
39
-1
-2
-2
Q_
0
O
0
89
88
87
87
87
-3
-3
86
-6
Q_
O
o
Q_
30
1
1
3
3
3
38
13
-2
-3
Q_
<
30
0
0
0
1
0
9
8
-2
-2
Q.
LU
30
0
1
1
0
1
26
74
-2
83
G-25
-------
APPENDIX H - REPORT ON LIFE CYCLE IMPACTS OF NEW
COMMERCIAL BUILDING CONSTRUCTION
The following report was developed for EPA in July 2010 as a follow-on to the Sustainable Materials
Management Relative Ranking Analysis to analyze the life cycle impacts associated with "new office,
industrial and commercial building construction."
The methods used for analysis of new office, industrial and commercial building construction were
consistent with those described herein for the analysis of life cycle impacts associated with single-family
homes, with the following exceptions:
• The analysis of new office, industrial and commercial building construction did not include
analyses of material input and waste impact categories;
• The analysis of new office, industrial and commercial building construction did not include
analyses of the use and end-of-life life cycle phases of these types of buildings; and
• The analysis of new office, industrial, and commercial building construction was completed using
CEDA 3.0, incorporating BEA 2002 input-output tables.
In addition, several terminological refinements have been incorporated into this more recent report on
single-family homes to better communicate the concepts, methodologies, and results to a wider audience.
Specifically, the reader is referred to the Glossary of Terms and Appendix B of this single-family homes
report for more complete definitions of terms and impact categories.
Finally, the findings and conclusions presented in the new office, industrial and commercial building
construction report in this appendix reflect the insights that can be gained and limitations of input and
output contribution analyses (see Section 2 of the single-family homes report for a more detailed
discussion). The findings and conclusions of the analysis of life cycle impacts associated with new office,
industrial and commercial building construction have not been subject to more in-depth supply chain
analyses, nor have they benefited from more in-depth peer review. More detailed analyses and peer
review could offer additional insights and refinements to the findings and conclusions presented herein.
H-l
-------
Contribution analysis for
new commercial building
construction
New office, industrial and commercial building
construction
July, 2010
(Updated with editorial revisions November, 2011)
H-2
-------
INTRODUCTION
The EPA report, Sustainable Materials Management: The Road Ahead (EPA, 2009) lays out EPA's
vision for shifting our society's focus from managing wastes to managing materials by taking a broader
life-cycle view of materials management. The report included an analysis of priority materials, products,
and services whose consumption results in the largest environmental impacts, material use, waste, water
use and energy use in our economy (the 2020 Vision Relative Ranking Analysis). The analysis utilized
the Comprehensive Environmental Data Archive (CEDA) 3.0 for deriving direct, intermediate and final
consumption-based impacts and a vector analysis for ranking materials, products, and services based on
multiple criteria. CEDA 3.0 conducts input-output life-cycle impact analyses using U.S. Bureau of
Economic Analysis (BEA) data and various environmental statistics including the Toxic Releases
Inventory (TRI) and the U.S. Greenhouse Gas inventory (Suh, 2005).
Among the highest ranked materials, products, and services identified in the Sustainable Materials
Management report was the "New office, industrial and commercial building construction" product
category, referred to herein for simplicity as "new commercial building construction." From a final
consumption perspective, new commercial building construction was ranked among the top 20 materials,
products, and services when all impacts and resource use categories were considered. In addition, the
2020 Vision Relative Ranking analysis indicated that the impacts associated with new commercial
building construction are widespread, ranking it among the top 20 materials, products and services based
on 9 of 13 environmental impact and resource use categories.
In order to better understand this finding, a contribution analysis was conducted to identify direct inputs
to and supply-chain processes associated with new office, industrial and commercial building
construction that contribute most significantly to the environmental and resource consumption impacts.1
APPROACH
The contribution analysis considers the contribution of inputs to and supply chain processes associated
with new office, industrial and commercial building construction in terms of the following 15 impact
categories:
• Abiotic depletion
• Land use
• Global warming
• Ozone layer depletion
• Human toxicity
• Freshwater aquatic ecotoxicity
• Marine aquatic ecotoxicity
• Terrestrial ecotoxicity
• Freshwater sedimental ecotoxicity
• Marine sedimental ecotoxicity
• Photochemical oxidation
• Acidification
1 For supplemental information, contact Alison Kinn, Office of Pollution Prevention and Toxics, U.S. EPA.
H-3
-------
• Eutrophication
• Energy consumption
• Water consumption
• Acidification
• Eutrophication
• Energy consumption
• Water consumption
Three types of contribution analysis were performed for each of the 15 impact categories.
• Scope analysis
• Input contribution analysis
• Output contribution analysis
Each of these analyses provides a different perspective on the impacts associated with new office,
industrial and commercial building construction, including impacts embodied in major inputs (e.g., raw
materials and manufactured products) and impacts generated during the construction (e.g., emissions from
construction equipment).
The scope analysis takes the broadest view, evaluating contributions to impact among impacts associated
with on-site activities, impacts associated with the generation of electricity used in the construction, and
all other impacts associated with inputs to the construction (e.g., from the extraction and delivery of raw
materials, manufacture of products such as windows and doors or siding, etc.).
The input and output contribution analyses take a closer look at the direct inputs and supply chain
processes contributing to the impacts associated with the construction of new office, industrial and
commercial buildings. The input contribution analysis focuses on direct inputs to the new construction.
The output contribution analysis allocates the impacts embodied in these direct inputs back through the
supply chain.
Both types of analyses consider the impacts of inputs to the construction relative to direct on-site impacts.
Both types of analyses are conducted first on an aggregated basis using categories such as "raw materials"
and "manufactured products." A more detailed analysis is then conducted to identify specific direct
inputs and supply chain processes that contribute most significantly to the impacts associated with new
office, industrial and commercial building construction.
Figure 1 provides a general overview of the approach used to conduct this contribution analysis. More
detail regarding the approach is provided in Appendix A, and the results of the analyses are presented in
Appendix B. A more detailed description of the methodologies used for contribution analysis is not
within the scope of this report; interested readers are encouraged to consult the references cited in this
report for further details.
H-4
-------
Figure 1
Overview of Methodology for Contribution Analysis
Upstream Inputs
Raw materials to
produce direct inputs
Transportation and
logistics to produce
direct inputs
Energy and utilities to
produce direct inputs
Intermediate
manufacturing to
produce direct inputs
Services used to
produce direct inputs
Direct Inputs
Raw materials used in
construction
Transportation of goods
and materials to site
Energy and utilities
delivered to site
Manufactured goods
used in construction
Construction-related
services
Environmental Impacts Associated with Inputs:
• Abiotic depletion
Land use
Global warming
Ozone layer depletion
Human toxicity
Freshwater aquatic ecotoxicity
Marine aquatic ecotoxicity
• Terrestrial ecotoxicity
• Freshwater sedimental
ecotoxicity
• Marine sedimental
ecotoxicity
• Photochemical oxidation
• Acidification
• Eutroohication
Resource Use Associated with Inputs:
• Energy consumption
• Water consumption
New office, industrial and
commercial buildings
Environmental Impacts Associated with On-site Construction:
• Abiotic depletion • Terrestrial ecotoxicity
• Land use
• Global warming
• Ozone layer depletion
• Human toxicity
• Freshwater aquatic ecotoxicity
• Marine aquatic ecotoxicity
Freshwater sedimental
ecotoxicity
Marine sedimental
ecotoxicity
Photochemical oxidation
Acidification
Eutroohication
Resources Used during On-site Construction:
• Energy consumption
• Water consumption
Explanation of Contribution Analysis Methodology:
• The overall scope of the life-cycle analysis includes input and construction stages; it does not include the use stage and does not
fully capture the end-of-life stage.
• The dotted line around inputs depicts the scope of the input stage of the life-cycle analysis.
• The aggregated contribution analyses (Appendix B, Tables B2 and B4) consider both input and construction stages; the detailed
contribution analyses (Appendix B, Tables B3 and B5) address inputs only.
• Input contribution analysis accumulates life-cycle impacts at the level of "Direct Inputs," as shown above, plus direct
emissions/consumption during construction.
• Output contribution analysis disaggregates life-cycle impacts to the level of "Upstream Inputs," as shown above, plus direct
emissions/consumption during construction.
H-5
-------
Scope analysis
According to the scope analysis (Appendix B, Table Bl and associated figures), environmental impacts
and energy/water use associated with inputs, other than electricity (i.e., Scope 3 impacts) dominate the
overall life-cycle impacts associated with new office, industrial and commercial building construction.
Most of the environmental impacts and energy and water consumption associated with new commercial
building construction is embodied in the materials, products, and services and occurs prior to the actual
construction.
Nonetheless, direct impacts by new commercial building construction activities (Scope 1 impacts) are
reasonably significant in terms of global warming impacts, photochemical oxidation, acidification,
eutrophication, and overall energy use. Direct global warming, photochemical oxidation, and acidification
impacts as well as energy consumption are likely associated with on-site fossil fuel combustion during
new commercial building construction activities (e.g., while operating construction equipment).
Eutrophication impacts are likely associated with site run-off.
Input Contribution Analysis
According to the aggregated input contribution analysis (Appendix B, Table B2 and associated figures),
impacts embodied in direct inputs used in new commercial building construction contribute most
significantly to the total life-cycle impacts associated with this activity. While less significant,
transportation and logistics (e.g., wholesale and retail trade) services associated with delivering materials
and products to the job site contribute 5-12% in various impact categories. Other construction services
(e.g., engineering, architectural, and surveying) also embodied from 5-12% of the overall impact in
various impact categories.
The results of detailed input contribution analysis (Appendix B, Table B3) identify the ten direct inputs to
residential construction that contribute most significantly within each impact category. The analysis
identifies fabricated metal products in the list of the inputs contributing most significantly in all of the
impact and resource use categories where new commercial building construction was ranked highly in the
2020 Vision analysis. Fabricated metal products ranked among the top ten inputs include:
• Prefabricated metal buildings and components
• Pipe, valves, and pipe fittings
• Fabricated structural metal
• Miscellaneous structural metal work
• Sheet metal work
• Metal doors, sash, frames, molding, and trim
• Non-ferrous wiredrawing and insulating
In addition, the category "motor vehicles and passenger car bodies" is identified as a significant
contributor in several impact categories. This most likely reflects the use of light-duty vehicles in the
construction trade. It may also reflect some cross-categorization in the BEA data with the "construction
machinery and equipment" product category.
H-7
-------
In addition to fabricated metal products, several non-metallic mineral products are identified as
contributing significantly, particularly relative to some of the impact categories. Non-metallic mineral
products ranked among the top ten inputs include:
• Brick and structural clay tile (human toxicity, marine aquatic ecotoxicity and freshwater
sedimental ecotoxicity)
• Hydraulic cement and ready-mixed concrete (global warming, photochemical oxidation,
acidification, and eutrophication)
• Cut stone and stone products (ozone layer depletion, human toxicity, and marine sedimental
ecotoxicity)
Other inputs identified by the analysis as providing significant contributions include plastic products
(ozone depletion, human toxicity, ecotoxicity categories), paints and allied products (ozone depletion,
ecotoxicity categories), and carpets and rugs (ecotoxicity categories).
In general, the analysis showed that contributions to significant impacts were widely dispersed across
direct inputs to new commercial building construction. In most cases, the top ten ranked materials,
products, and services accounted for less than half of the overall impact associated with new commercial
building construction, and the top ranked input typically accounted for less than 10% of the overall
impact. The analysis identified two exceptions to this latter finding: brick and structural clay tile
contributed 25% of the overall impact associated with marine aquatic ecotoxicity and 22% of the overall
impact associated with freshwater sedimental ecotoxicity.
The results show the significance of fabricated metal products used in new commercial buildings and
construction equipment from the standpoint of environmental impact. The results also emphasize the
significance of basic building materials such as brick, structural clay tile, cement, ready-mixed concrete,
cut stone and stone products as well as chemically-derived products such as plastics and paints and
interior products such as carpets and rugs. In addition, service inputs such as engineering, architectural
and surveying and transportation through retail and wholesale trade show significant contributions
throughout the impact categories considered.
Output Contribution Analysis
Output contribution analysis allocates the impacts associated with direct inputs to the major processes
involved in the supply chain associated with construction of new office, industrial, and commercial
buildings. This analysis expands upon the information presented in the input analysis by identifying
processes earlier in the supply chain that contribute most significantly to the overall impacts and resource
use. Output contribution analysis, for example, can indicate impacts that are primarily associated with
energy inputs or impacts associated with emissions resulting from the extraction of raw materials. In
addition, output contribution analysis can highlight industries not identified in the input analysis, for
example, where impacts are highly concentrated in early supply chain processes but are then allocated
across a diverse range of final inputs.
The aggregated output contribution analysis (Appendix B, Table B4 and associated figures) shows that
impacts associated with intermediate and final product manufacturing continue to dominate in terms of
contribution to overall life-cycle impacts. However, the analysis also reveals the relatively greater
importance of impacts generated during raw material extraction, impacts associated with energy and
utility inputs, and transportation-related impacts as compared to input contribution analysis results.
H-8
-------
For example, the raw material extraction phase dominates abiotic depletion. This result reflects the fact
that the impacts associated with these earlier phases in the supply chain are embodied in direct inputs to
commercial building construction mainly in the form of manufactured products (as measured in the input
contribution analysis).
In addition to raw materials extraction and manufacturing, the use of energy and utilities contributes
significantly to overall life-cycle impacts in fossil fuel combustion-related impact categories such as
global warming, marine aquatic ecotoxicity, freshwater sedimental ecotoxicity, photochemical oxidation,
and acidification. Use of energy and utilities dominates the water use category, as this category is defined
in terms of "use" rather than "consumption" and, thus, the use of water for hydropower generally eclipses
other uses.
The detailed output contribution analysis (Appendix B, Table B5) identifies the ten life-cycle processes
that contribute most significantly to the life-cycle impacts associated with commercial building
construction. Frequently appearing processes include:
• Metals and related processes, including iron and ferroalloy ores, copper ore, other non-ferrous
metal ores, blast furnaces and steel mills, primary smelting and refining of copper, primary
aluminum, and other primary non-ferrous metals
• Non-metallic minerals and related processes/products, including brick and structural clay tile, cut
stone and stone products, glass and glass products, and ceramic wall and floor tile
• Industrial inorganic and organic chemicals and plastic materials and resins
• Paper and paperboard mills, pulp mills, and sawmills and planing mills
• Utilities, including electric services and sanitary services, steam supply, and irrigation
• Transportation-related processes
Among others, electric services (utilities) is not only one of the most frequent supply-chain process but
also one of the largest contributors of impacts, ranked number 1 in 9 out of 15 impact categories.
The output analysis demonstrates how the demand for a complex product, such as new commercial
buildings can contribute to certain environmental mechanisms through multiple supply chains and
mechanisms. For example, the analysis consistently shows three process sectors - electric utilities, blast
furnaces and steel mills, and hydraulic cement - as major contributors to global warming, photochemical
oxidation, and acidification. Review of the output contribution analysis for energy consumption suggests
that electric services and blast furnaces and steel mills contribute to these impacts via fossil fuel
combustion to meet high energy needs. In contrast, the energy consumption results for hydraulic cement
suggest that direct, non-combustion emissions from this industry are a significant source of the global
warming, photochemical oxidation, and acidification impacts associated with new commercial building
construction.
The output contribution analysis also highlights processes associated with inputs to new commercial
building construction that were not consistently identified in the input contribution analysis, including
wood products, glass, and ceramics. This finding emphasizes the value of examining impacts from
multiple perspectives. For example, the 2020 Vision Relative Ranking Analysis ranked new commercial
building construction among the top 20 materials, products, and services relative to marine sedimental
ecotoxicity. The input contribution analysis does not identify forest products among the top ten
contributors to these impacts. In contrast, the output perspective identifies paper and paperboard mills
and pulp mills contributing 21% of the marine sedimental ecotoxicity impacts. This suggests that the
impacts occur early in the supply chain and are then widely distributed among finished pulp and paper
products used in new commercial building construction (e.g., reconstituted wood panels, construction
papers).
H-9
-------
The contribution analyses are further summarized in Appendix C, which compiles the results of each of
the analyses for each of the environmental and resource use impact categories. By compiling the three
perspectives by impact category, the tables offer further insights into the locus of impacts along the
supply chain associated with new commercial building construction.
Review of the input and output contribution analysis results side-by-side suggests the following high-
level supply chain patterns:
• Where the input contribution analysis indicates that metal products contribute most significantly
to an impact, the output contribution analysis often highlights processes requiring high energy
(electric services, blast furnaces and steel mills). This suggests that the use of fabricated metal
products in new commercial building construction contributes significantly to the impacts of this
sector due to the high energy associated with their supply chain, from extraction and primary
processing through fabrication.
• Where primary building materials, such as brick and structural clay tile, stone and stone products,
and cement and concrete, are identified as significant contributors to an impact, they are often
identified as such from both input and output perspectives. This reflects the relatively minimal
processing of these materials prior to their use in new commercial building construction. Impacts
associated with extraction and early processing stages are not distributed among multiple inputs
via the supply chain.
The diversity of the results of the input and output contribution analyses provides initial insights into the
complexity of the relationship between new commercial building construction and its impact on the
environment.
For example, the input contribution analysis suggests that fabricated metal products, non-metallic mineral
products, and plastic products all contribute significantly to the human toxicity impacts associated with
new commercial building construction. Review of the aggregate and detailed output contribution
analyses suggests that a significant proportion of these impacts occur at the extraction stage and impacts
occur through multiple environmental compartments (e.g., air emissions, water discharges). Review of
the input and output contribution analyses relative to global warming impacts suggests a far less complex
situation.
The complexity of the supply chain processes contributing to an environmental or resource use impact has
implications for approaches for addressing these impacts, both in terms of the locus of action and the
nature of the action. For example, in the case of brick and structural clay tile and its contribution to
marine aquatic ecotoxicity, the analysis suggests the potential efficacy of policies focused narrowly on
this one product area. Further, the close linkage between input and output contribution findings suggests
that either end-product- or process-oriented policies could be effective. In contrast, the complexity of the
impacts relative to human toxicity suggests that a more multi-faceted approach, involving, for example,
multiple product standards and/or coordination among multiple environmental programs, would be
needed to address this impact.
A more complete understanding of these supply chain interactions and their implications for policy action
is beyond the scope of this study. Other, more detailed analyses, such a structural path analysis, could be
used to further explore the findings suggested by the analyses described herein.
H-10
-------
In summary, the overall life-cycle impacts associated with new commercial building construction are
characterized by significant amounts of on-site fossil fuel combustion; substantial use of energy-intensive
inputs such as prefabricated metal building components, pipes, valves, pipe fittings, and construction
equipment; transportation services (including retail/wholesale trade); and a complex array of products
whose production involves significant amounts of toxic emissions (e.g., brick and structural clay tile, cut
stone and stone products, plastic products, and wood products).
While many other products are manufactured using either energy intensive products or toxic emission-
intensive products, commercial building construction incorporates both energy and toxic emission-
intensive product inputs. The complex integration of materials, products, services, resources, and other
inputs and their associated life-cycle impacts, combined with the direct impacts generated on-site,
explains the relatively high ranking calculated for new commercial building construction in the
Sustainable Materials Management Relative Ranking analysis.
Impacts embodied in direct inputs to new commercial building construction originate from significant
life-cycle use of fossil fuel combustion-intensive products and services such as electric services, industrial
inorganic and organic chemicals, ferrous and non-ferrous metals, and transportation and logistics. The
use of these products and services in commercial building construction contributes not only to global
warming and acidification but to other environmental impacts, as well. In addition, the complex mix of
fabricated metal, non-metallic mineral, chemical, and forest product inputs used in commercial building
construction contributes to air quality, human toxicity, and ecological toxicity impacts resulting from
emissions via multiple environmental compartments.
As a point of comparison, the contribution analysis of new commercial building construction differs from
the contribution analysis previously completed for new 1-unit residential building construction, primarily
with regard to the environmental significance of fabricated metal products associated with building
components and construction equipment. The analysis of new commercial building construction also
stands out with regard to the lesser significance from an environmental standpoint of wood-based and
plastic product inputs. On the other hand, both new residential and new commercial building construction
share many common environmentally significant supply-chain processes including non-metallic mineral
processes and materials (e.g., concrete, brick and structural clay tiles), electric services, and
transportation-related processes.
REFERENCES
EPA, 2009: Sustainable Materials Management: the road ahead, EPA530R09009, Washington D.C.,
USA.
Heijungs, R., Suh, S., 2002: The Computational Structure of Life Cycle Assessment, Kluwer Academic
Publisher, Dor-drecht, The Netherlands.
Suh, S., 2005: Developing Sectoral Environmental Database for Input-Output Analysis: Comprehensive
Environmental Data Archive of the U.S., Economic Systems Research, 17 (4), 449 - 469
H-ll
-------
APPENDIX H-A
Contribution analysis is used to gain insights regarding life-cycle assessment (LCA) results by identifying
major "drivers" that shape the overall results. What is referred to here as "drivers" can include many
things. For instance, drivers can be direct inputs to the main process in question such as "steel beams" to
commercial building construction. A driver can also be a supply-chain process within the life cycle of a
product such as "iron ore mining." While, iron ore may not be directly used in new commercial building
construction, it is related to new commercial building construction through the supply chain by which
iron ore is processed to form steel beams. In addition, a driver could be a particular substance that
contributes substantial portion of a characterized result such as CO2 for global warming.
In general, LCA studies often distinguish among the following classes of drivers:
• Direct inputs to a main process
• Supply-chain process
• Life cycle inventory item
• Life cycle impact category
• Life cycle stages
In addition, GHG accounts often distinguish "scopes". Scope 1 refers to on-site, direct emission from the
main process in question, Scope 2 refers to emissions from electricity generation directly used by the
main process, and Scope 3 refers to all other emissions from the supply-chain. Such a distinction helps us
belter understand the role of direct emissions and supply-chain induced emissions relative to total
emissions.
The mode of computation and the level of aggregation used in LCA depend on the class of drivers
selected and reflect different ways of slicing the total (Heijungs and Suh, 2002). Analysts often choose
multiple classes of drivers to enable insights from multiple perspectives, which together help better
understanding the whole picture.
In this report, we employed three classes of drivers for contribution analysis: (1) scopes, (2) direct inputs
(input contribution analysis) and (3) life-cycle processes (output contribution analysis). The product
considered in this study (new commercial building construction) involves at least 200 inputs and supply-
chain processes, and, therefore, presentation of all of the contributions of all inputs and supply-chain
processes would be impractical and difficult to interpret. Thus, direct inputs and life-cycle processes are
shown in two different levels of aggregation for ease of presentation.
H-12
-------
APPENDIX H-B - DETAILED CONTRIBUTION ANALYSIS RESULTS FOR COMMERCIAL BUILDING
H-Bl. SCOPE ANALYSIS FOR NEW COMMERCIAL BUILDING CONSTRUCTION
This analysis shows where impacts take place in the entire life-cycle. Scope 1 impacts are the impacts associated with the operation of the production facility (on-
site impact), Scope 2 impacts are the impacts associated with the direct electric utility supplier to the production facility, and Scope 3 impacts are the impacts
associated with the rest of the supply-chain.
Table H-Bl. Scope analysis for new commercial building construction
Scope 1
Scope 2
Scope 3
Total
Scope 1
Scope 2
Scope 3
Total
Abiotic depletion
0%
2%
98%
100%
Freshwater
sedimental
ecotoxicity
FSETP inf.
0%
2%
98%
100%
Land use increase
of land
competition
Marine
sedimental
ecotoxicity
MSETP inf.
0%
0%
100%
100%
0%
0%
100%
100%
Global warming
GWP100
22%
1%
76%
100%
Photochemical
oxidation (high
NOx)
20%
1%
79%
100%
Ozone layer
depletion OOP
steady state
0%
0%
100%
100%
Acidification
(incl. fate,
average Europe
total, A&B)
7%
3%
90%
100%
Human toxicity
HTPinf.
0%
1%
99%
100%
Eutrophication
(fate not incl.)
15%
1%
84%
100%
Freshwater
aquatic
ecotoxicity
FAETP inf.
Energy
Marine aquatic
0%
0%
100%
100%
consumption
(mBTU)
6%
2%
91%
100%
ecotoxicity
MAETPinf
Water
0%
3%
97%
100%
Terrestrial
ecotoxicity TETP
inf
0%
0%
100%
100%
consumption
(gallon)
0%
8%
92%
100%
H-13
-------
Abiotic depletion
Scope 1 Scope 2,
2%
Landuse
Scope 2, _ rScopel,
Global warming
Ozone layer depletion
Scope 1,^ Sc°Pe2'
Human toxicity
Scope 1 Scope 2,
0% \S 1%
Freshwater aquatic ecotoxicity
Scope 2 Scope 1,
Marine aquatic ecotoxicity
Scope 2,
Terrestrial ecotoxicity
Scope 1 Scope 2,
0%
Freshwater sedimental ecotoxicity
Scope 1 Scope 2,
0% \^ / 2%
Marine sedimental ecotoxicity
Scope 1 Scope 2,
Acidification
Scope^
Photochemical oxidation
Eutrophication
Energy consumption
Water consum ption
'ope 2,
Scope 2,
ie2,
Figure H-B1. Pie charts for Scope Analysis (new commercial building construction)
H-14
-------
H-B2. TOTAL IMPACT ALLOCATED OVER DIRECT INPUTS AND ON-SITE OPERATION (AGGREGATED) FOR NEW
COMMERCIAL BUILDING CONSTRUCTION
This analysis shows the relative importance of direct inputs to and on-site emission/use by new commercial building construction in terms of their contributions to
each impact. A total of 205 direct inputs to new commercial building construction are aggregated into five categories: Raw material extraction, Transportation and
logistics, Energy and utility, Manufacturing, and Service.
Table H-B2. Input contribution analysis for new commercial building construction
Raw material extraction
Transportation and logistics
Energy and utility
Manufacturing
Service
Direct emission/consumption
Total
Raw material extraction
Transportation and logistics
Energy and utility
Manufacturing
Service
Direct emission/consumption
Total
Abiotic
depletion
1%
10%
3%
79%
8%
0%
100%
Freshwater
sedimental
ecotoxicity
0%
5%
3%
86%
6%
0%
100%
Land use
20%
12%
0%
60%
9%
0%
100%
Marine
sedimental
ecotoxicity
1%
6%
0%
85%
7%
0%
100%
Global
warming
1%
7%
3%
61%
6%
22%
100%
Photochemica
1 oxidation
1%
9%
2%
62%
7%
20%
100%
Ozone layer
depletion
0%
4%
0%
89%
6%
0%
100%
Acidification
0%
9%
4%
72%
8%
7%
100%
Human
toxicity
0%
5%
1%
88%
5%
0%
100%
Eutrophication
3%
9%
2%
65%
7%
15%
100%
Freshwater
aquatic
ecotoxicity
11%
5%
2%
76%
6%
0%
100%
Energy
consumption
1%
11%
3%
71%
8%
6%
100%
Manne _ . . ,
Terrestrial
aquatic . . ..
^ . .. ecotoxicity
ecotoxicity
0%
5%
3%
86%
6%
0%
100%
Water
consumption
1%
12%
8%
66%
12%
0%
100%
7%
5%
2%
80%
6%
0%
100%
H-15
-------
Abiotic depletion
Landuse
Service, 8%,
Direct
emission/cons
umption,0%
Raw material
.extraction, 1%
Energy and
utility, 3%
Global warming
Raw material
extraction, 1%
Transportation
and logistics,
7%
Energy and
utility, 3%
Transportati
on and
logistics,
12%
Direct
emission/cons
umption, 22%
Energy
and
utility, 0%
Ozone layer depletion
Direct
emission/cons
umption, 0%
Service, 6%
Raw material
extraction, 0%
Transportation
and logistics,
4%
.Energy and
utility, 0%
Direct
emission/cons
umption, 0%.
Service, 5%.
Human toxicity
Raw material
extraction, 0%
Transportation
and logistics,
5%
Freshwater aquatic ecotoxicity
Raw material
.extraction,
11%
Ens
ut
Direct
emission/cons
umption, 0%
Service, 6%
Transportatio
nand
logistics, 5%
^Energyand
utility, 2%
Figure H-B2a. Input contribution analysis for new commercial building construction
H-16
-------
Service, 6%,
Marine aquatic ecotoxicity
Raw material
extraction,
0%
.Transportatio
nand
logistics, 5%
Energy and
utility, 3%
Direct
emission/cons
umption, 0%
Service, 6%
Terrestrial ecotoxicity
Raw material
extraction, 7%
Transpc
andlo
5
Freshwater sedimental ecotoxicity
Direct Raw material
emission/con
sumption, 0%
Service, 6%.
^xtraction,
0%
Transportatio
nand
logistics, 5%
Energy and
utility, 3%
Service, 7%
Marine sedimental ecotoxicity
Direct
emission/con
sumption, 0%
Photochemical oxidation
Transport;
nand
.logistics, 6
Raw material
extraction, 1%
Transportation
and logistics,
Energy and
.utility, 2%
Direct
emission/cons
umption, 20%
Acidification
Direct Transportation
emission/cons and|ogisticS;
umption, 7%
Energy and
utility, 4%
Figure H-B2b. Input contribution analysis for new commercial building construction
H-17
-------
Eutrophication
Energy consumption
Water consumption
Raw material
extraction, 3%
Direct
emission/cons
Service,
Transportatio
nand
.logistics, 9%
Energy and
utility, 2%
Direct
emission/cons
umption, 6%
Transportatio
nand
logistics, 11%
Energy and
utility, 3%
Service, 12%
Direct
emission/cons Transportatio
umption, 0% n and
logistics, 12%
Figure H-B2c. Input contribution analysis for new commercial building construction
H-18
-------
H-B3. TOTAL SUPPLY-CHAIN IMPACT ALLOCATED OVER DIRECT INPUTS (DETAILS FOR TOP 10 CONTRIBUTORS)
This analysis shows the relative importance of direct inputs to new commercial building construction in terms of their contribution to each impact. A total of 205
direct inputs to new commercial building construction are distinguished in the analysis, and the 10 inputs contributing most significantly to the life cycle impact
are identified for each impact category in this table.
Table H-B3. Input contribution analysis for new commercial building construction—detail for top 10 inputs
Rank
1
2
3
4
5
6
7
8
9
10
Abiotic depletion
Prefabricated metal buildings and components
Engineering, architectural, and surveying
Motor vehicles and passenger car bodies
Fabricated structural metal
Retail trade, except eating and drinking
Pipe, valves, and pipe fittings
Wholesale trade
Miscellaneous structural metal work
Sheet metal work
Petroleum refining
The rest
Total
Contribution
5%
4%
4%
4%
4%
3%
3%
3%
3%
3%
64%
100%
Land use
Feed grains
Sawmills and planing mills, general
Trucking and courier services, except air
Veneer and plywood
Motor vehicles and passenger car bodies
Millwork
Engineering, architectural, and surveying
Wholesale trade
Eating and drinking places
Retail trade, except eating and drinking
The rest
Total
Contribution
19%
8%
6%
4%
4%
3%
3%
3%
2%
2%
46%
100%
Global warming
Prefabricated metal buildings and components
Cement, hydraulic
Ready-mixed concrete
Motor vehicles and passenger car bodies
Engineering, architectural, and surveying
Fabricated structural metal
Pipe, valves, and pipe fittings
Retail trade, except eating and drinking
Wholesale trade
Miscellaneous structural metal work
The rest
Total
Contribution
5%
4%
4%
4%
4%
4%
3%
3%
3%
3%
63%
100%
Rank
1
2
3
4
5
6
7
8
9
10
Ozone layer depletion
Cut stone and stone products
Pipe, valves, and pipe fittings
Misc. plastics products
Metal doors, sash, frames, molding, and trim
Motor vehicles and passenger car bodies
Paints and allied products
Prefabricated metal buildings and components
Sheet metal work
Nonferrous wiredrawing and insulating
Lighting fixtures and equipment
The rest
Total
Contribution
11%
7%
5%
5%
4%
4%
4%
3%
3%
3%
53%
100%
Human toxicity
Nonferrous wiredrawing and insulating
Pipe, valves, and pipe fittings
Brick and structural clay tile
Prefabricated metal buildings and components
Motor vehicles and passenger car bodies
Cut stone and stone products
Metal doors, sash, frames, molding, and trim
Sheet metal work
Miscellaneous plastics products, n.e.c.
Engineering, architectural, and surveying
The rest
Total
Contribution
6%
5%
4%
4%
4%
4%
3%
3%
3%
3%
62%
100%
Freshwater aquatic ecotoxicity
Feed grains
Carpets and rugs
Motor vehicles bodies
Nonferrous wiredrawing and insulating
Pipe, valves, and pipe fittings
Miscellaneous plastics products, n.e.c.
Prefabricated metal buildings and components
Wholesale trade
Engineering, architectural, and surveying
Paints and allied products
The rest
Total
Contribution
11%
8%
6%
3%
3%
3%
2%
2%
2%
2%
56%
100%
H-19
-------
Rank
1
2
3
4
5
6
7
8
9
10
Marine aquatic ecotoxicity
Brick and structural clay tile
Metal doors, sash, frames, molding, and trim
Prefabricated metal buildings and components
Motor vehicles and passenger car bodies
Sheet metal work
Engineering, architectural, and surveying
Retail trade, except restaur.
Pipe, valves, and pipe fittings
Electric services (utilities)
Ceramic wall and floor tile
The rest
Total
Contribution
25%
5%
4%
3%
3%
3%
3%
3%
3%
2%
47%
100%
Terrestrial ecotoxicity
Feed grains
Carpets and rugs
Motor vehicles and passenger car bodies
Nonferrous wiredrawing and insulating
Pipe, valves, & pipe fittings
Prefabricated metal buildings and components
Misc. plastics products
Wholesale trade
Engineering, architectural, and surveying
Metal doors, sash, frames, molding, and trim
The rest
Total
Contribution
7%
6%
5%
5%
4%
3%
3%
2%
2%
2%
60%
100%
Freshwater sedimental ecotoxicity
Brick and structural clay tile
Metal doors, sash, frames, molding, and trim
Prefabricated metal buildings and components
Motor vehicles and passenger car bodies
Sheet metal work
Engineering, architectural, and surveying
Pipe, valves, and pipe fittings
Nonferrous wiredrawing and insulating
Retail trade, except eating and drinking
Glass and glass products, except containers
The rest
Total
Contribution
22%
5%
4%
3%
3%
3%
3%
3%
3%
2%
50%
100%
Rank
1
2
3
4
5
6
7
8
9
10
Marine sedimental ecotoxicity
Cut stone and stone products
Miscellaneous plastics products, n.e.c.
Motor vehicles and passenger car bodies
Wholesale trade
Engineering, architectural, and surveying
Paints and allied products
Metal doors, sash, frames, molding, and trim
Photographic equipment and supplies
Prefabricated metal buildings and components
Lighting fixtures and equipment
The rest
Total
Contribution
7%
5%
4%
4%
3%
3%
3%
3%
3%
3%
62%
100%
Photochemical oxidation
Trucking and courier services, except air
Prefabricated metal buildings and components
Motor vehicles and passenger car bodies
Engineering, architectural, and surveying
Ready-mixed concrete
Pipe, valves, and pipe fittings
Fabricated structural metal
Wholesale trade
Retail trade, except eating and drinking
Cement, hydraulic
The rest
Total
Contribution
5%
4%
4%
4%
3%
3%
3%
3%
3%
3%
65%
100%
Acidification
Cement, hydraulic
Engineering, architectural, and surveying
Ready-mixed concrete
Prefabricated metal buildings and components
Motor vehicles and passenger car bodies
Retail trade, except eating and drinking
Electric services (utilities)
Pipe, valves, and pipe fittings
Wholesale trade
Fabricated structural metal
The rest
Total
Contribution
6%
5%
5%
4%
4%
4%
4%
3%
3%
3%
59%
100%
Rank
1
2
3
4
5
6
7
8
9
10
Eutrophication
Cement, hydraulic
Ready-mixed concrete
Motor vehicles and passenger car bodies
Engineering, architectural, and surveying
Trucking and courier services, except air
Prefabricated metal buildings and components
Feed grains
Wholesale trade
Retail trade, except eating and drinking
Fabricated structural metal
The rest
Total
Contribution
5%
4%
4%
4%
4%
4%
3%
3%
3%
3%
64%
100%
Energy consumption
Prefabricated metal buildings and components
Engineering, architectural, and surveying
Retail trade, except eating and drinking
Fabricated structural metal
Motor vehicles and passenger car bodies
Wholesale trade
Pipe, valves, and pipe fittings
Miscellaneous structural metal work
Sheet metal work
Electric services (utilities)
The rest
Total
Contribution
6%
5%
4%
4%
4%
4%
4%
3%
3%
3%
62%
100%
Water consumption
Electric services (utilities)
Engineering, architectural, and surveying
Retail trade, except eating and drinking
Wholesale trade
Motor vehicles and passenger car bodies
Prefabricated metal buildings and components
Pipe, valves, and pipe fittings
Fabricated structural metal
Miscellaneous plastics products, n.e.c.
Sheet metal work
The rest
Total
Contribution
8%
8%
6%
4%
4%
4%
4%
3%
2%
2%
55%
100%
H-20
-------
Abiotic depletion
Landuse
Motor vehicles
and passenger
car bodies, 4%
Fabricated
structura
metal,
Ozone layer depletion
Pipe,valves, and
pipe fittings, 7%
Miscellaneous
plastics
cts, n.e.c.,
5%
The rest, 53%
' Sheet metal
^ous work, 3%
Lighting fixtures wiredrawing
and equipment, and insulating,
3% 3%
Motor vehicles
and passenger
car bodies, 4%
Prefabricated
metal buildings
and
components,
4%
Global warming
Prefabricated
metal buildings Cement,
hydraulic, Ready_mixed
^concrete, 4%
VMillwork, 3%
^^ I ^ ~~~~~*^^^
Retail trade, _^ \ \ ^~~~~-~^_Engineering,
excepteating Eating and \_Wno|esa|e architectural,
drinking '
lotor vehicles
and passenger
car bodies, 4%
anddrinking,
2%
2%
S' trade, 3% and surveying
services,3%
.Pipe,valves, and
pipefittings, 3%
.Retail trade,
excepteating
and drinking,
3%
Human toxicity
Freshwater aquatic ecotoxicity
Pipe,valves, and
.pipefittings, 5%
Nonferrous
wiredrawin
and insulating,
Prefabricated
structural clay metal buildings
tile, 4%
ngmeermg;—^^Miscellaneous
rchitectural, plastics
and surveying products, n.e.c.,
services,3% 3%
Carpets and
rugs, 8
Nonferrous
.wiredrawing
and insulating,
3%
Pipe,valves, and
.Miscellaneous pipefittings, 3%
plastics
products, n.e.c.,
3%
Tefabricated
metal buildings
and
components,
2%
Figure H-B3a. Detailed input contribution analysis for new commercial building construction
H-21
-------
Marine aquatic ecotoxicity
Terrestrial ecotoxicity
Freshwater sedimental ecotoxicity
Ceramic
wall and
floortile,
.Retail trade,
Electric./ Pipe, valves, except eating
services and pipe anddrinking,
(utilities), 3% fittings, 3% 3%
Metal doors,
sash, frames,
molding, and
trim, 5%
Prefabricated
metal buildings
and
components,
4%
.Motor vehicles
and passenger
car bodies, 3%
.Engineering,
architectural,
and surveying
services,3%
Carpets and
rugs,6% Motorvehicles
and passenger
.car bodies, 5%
ie,valves, and
pipefittings, 4% Prefabricated
metal buildings
and
components,
.Miscellaneous
plastics
products, n.e.c.,
3%
Metal doors,
sash, frames,
molding, and
trim, 5%
Retail trade,
excepteating
anddrinking,
Pipe,valves, ancl
pipefittings, 3%
.Nonferrous
wiredrawing
and insulating,
Prefabricated
metal buildings
and
.components,
4%
Motor vehicles
and passenger
car bodies, 3%
.Sheet metal
work, 3%
-Engineering,
architectural,
and surveying
services,3%
Marine sedimental ecotoxicity
.Prefabricated
metal buildings
Lighting fixtures ,
and equipment,
components,
3% 3%
Photochemical oxidation
Acidification
Prefabricated
Trucking and metal buildings
courier services, ar)d
exceptair, 5% components,
The rest, 65%
Motor vehicles
and passenger
.car bodies, 4%
Engineering,
architectural,
.and surveying
services, 4%
Ready-mixed
concrete,3%
.Pipe,valves, and
pipefittings, 3%
.Retail trade,
.Cement, excepteating
hydraulic,3% anddrinking,
3%
Engineering,
architectural, Prefabricated
and surveying metal buildings
services, 5% Ready-mixed and
.components,
4%
te, 5%
Motor vehicles
and passenger
,car bodies, 4%
.Electric services
utilities), 4%
.Pipe,valves, and
pipefittings, 3%
i
Fabricated »
structural \-Wholesale
metal, 3% trade, 3%
Figure H-B3b. Detailed input contribution analysis for new commercial building construction
H-22
-------
Eutrophication
Energy consumption
Water consumption
Motor vehicles
Engineering,
architectural,
and surveying
services,4%
Truckingand
courierservices,
exceptair, 4%
Feed grains, 3%
Wholesale Retail trade.
Engineering, RetaNtradej
architectural, except
and surveying eatingand
:rvices,5%_drinkingj4%
' Fabricated
structural
netal, 4% Motor vehicles
and passenger
_car bodies, 4%
Prefabricated
metal buildings
and
components,
.Motor vehicles
and passenger
car bodies, 4%
Prefabricated
metal buildings
and
components,
Fabricated
structural
metal, 3%
Figure H-B3c. Detailed input contribution analysis for new commercial building construction
H-23
-------
H-B4. TOTAL IMPACT ALLOCATED OVER LIFE-CYCLE STAGES (AGGREGATED)
This analysis shows the relative importance of supply-chain processes and on-site emissions/use throughout the life-cycle of new commercial building construction
in terms of their contribution to each impact. A total of 480 processes are directly or indirectly involved in the supply-chain of new commercial building
construction, which are aggregated into five categories: Raw material extraction, Transportation and logistics, Energy and utility, Manufacturing, and Service.
Table H-B4. Output contribution analysis for new commercial building construction
Raw material extraction
Transportation and logistics
Energy and utility
Manufacturing
Service
Direct emission/consumption
Total
Raw material extraction
Transportation and logistics
Energy and utility
Manufacturing
Service
Direct emission/consumption
Total
Abiotic
depletion
98%
0%
0%
2%
0%
0%
100%
Freshwater
sedimental
ecotoxicity
6%
0%
28%
66%
1%
0%
100%
Land use
83%
17%
1%
0%
0%
0%
100%
Marine
sedimental
ecotoxicity
1%
0%
0%
97%
2%
0%
100%
Global
warming
5%
6%
20%
43%
2%
22%
100%
Photochemica
1 oxidation
4%
11%
15%
45%
5%
20%
100%
Ozone layer
depletion
0%
0%
0%
92%
7%
0%
100%
Acidification
2%
6%
41%
42%
1%
7%
100%
Human
toxicity
16%
1%
7%
75%
1%
0%
100%
Eutrophication
16%
14%
17%
36%
3%
15%
100%
Freshwater
aquatic
ecotoxicity
70%
0%
5%
23%
1%
0%
100%
Energy
consumption
2%
11%
30%
47%
4%
6%
100%
Marine
aquatic
ecotoxicity
4%
0%
31%
65%
0%
0%
100%
Water
consumption
2%
0%
95%
2%
0%
0%
100%
Terrestrial
ecotoxicity
55%
0%
5%
38%
1%
0%
100%
H-24
-------
Abiotic depletion
Manufacturing
,2%
Landuse
Energy and
utility, 1%
Global warming
Raw material
extraction, 5%
Transportatio
nand
logistics, 6%
Service,
Raw
material
extraction,
Direct
mission/cons
umption, 22%
Ozone layer depletion
Human toxicity
Service, 7%
Direct
emission/cons
umption, 0%
Service, 1%
Raw material
extraction,
16%
Transp
andk
Freshwater aquatic ecotoxicity
Direct
emission/cons
Service, 1% umption, 0%
Manufacturi
g, 23%
Energy and
utility, 5%
Figure H-B4a. Output contribution analysis for new commercial building construction
H-25
-------
Marine aquatic ecotoxicity
Service, 0%,
Raw material
extraction,
4%
Marine sedimental ecotoxicity
Service, 2%
Raw material
.extraction,
1%
Terrestrial ecotoxicity
Service, 1%
Transportation
and logistic$nergy
°°/° utility, 5%
Photochemical oxidation
Raw material
extraction, 4%
Transportation
and logistics,
11%
Freshwater sedimental ecotoxicity
Raw material
extraction,
Service, 1%^ / 6o/0
Energy and
utility, 28%
Acidification
Direct
emission/cons
Service,
Raw material
extractlon< 2%
_Transportation
and logistics,
Figure H-B4b. Output contribution analysis for new commercial building construction
H-26
-------
Eutrophication
Energy consumption
Water consumption
Service, 3'
Raw material
traction,
Direct
emission/cons
umption, 15%
Service, 4%
Direct
emission/cons Raw material Transportatio
umption, 6%_vextraction, 2% n and
logistics, 11%
Manufacturing Service<0%
Raw material
extraction, 2%
Figure H-B4c. Output contribution analysis for new commercial building construction
H-27
-------
H-B5. TOTAL IMPACT ALLOCATED OVER LIFE-CYCLE STAGES (DETAILED FOR TOP 10 CONTRIBUTORS)
This analysis shows the relative importance of supply-chain processes and direct emissions/use throughout the life-cycle of new commercial building construction
in terms of their contribution to each impact. A total of 480 processes are directly or indirectly involved in the supply-chain of new commercial building
construction, and the top 10 processes contributing most significantly to overall impact are identified for each impact category in this table.
Table H-B5. Output contribution analysis for new commercial building construction—detailed for top 10 processes
Rank
1
2
3
4
5
6
7
8
9
10
Abiotic depletion
Crude petroleum and natural gas
Coal
Petroleum refining
The rest
Total
Contribution
49%
49%
2%
0%
100%
Land use
Feed grains
Trucking and courier services, except air
Meat animals
Food grains
Poultry and eggs
Agricultural, forestry, and fishery services
Miscellaneous livestock
Cotton
Miscellaneous crops
Dairy farm products
The rest
Total
Contribution
26%
15%
10%
8%
7%
6%
6%
5%
5%
4%
6%
100%
Global warming
Electric services (utilities)
Blastfurnaces and steel mills
Cement, hydraulic
Sanitary services, steam supply, and irrigation...
Trucking and courier services, except air
Crude petroleum and natural gas
Air transportation
Coal
Petroleum refining
Lime
The rest
Total
Contribution
21%
15%
7%
4%
4%
3%
2%
1%
1%
1%
40%
100%
Rank
1
2
3
4
5
6
7
8
9
10
Ozone layer depletion
Industrial inorganic and organic chemicals
Primary aluminum
Cut stone and stone products
Plastics materials and resins
Primary nonferrous metals, n.e.c.
Miscellaneous repair shops
Pipe, valves, and pipe fittings
Synthetic rubber
Scrap
Miscellaneous plastics products, n.e.c.
The rest
Total
Contribution Human toxicity
20%
13%
10%
5%
5%
5%
5%
4%
2%
2%
28%
100%
Copper ore
Primary aluminum
Primary smelting and refining of copper
Electric services (utilities)
Industrial inorganic and organic chemicals
Nonmetallic mineral products, n.e.c.
Nonferrous metal ores, except copper
Paper and paperboard mills
Brick and structural clay tile
Pulp mills
The rest
Total
Contribution
9%
8%
8%
6%
5%
5%
5%
5%
4%
4%
41%
100%
Freshwater aquatic ecotoxicity
Cotton
Feed grains
Miscellaneous crops
Copper ore
Sanitary services, steam supply, and irrig...
Agricultural, forestry, and fishery services
Primary smelting and refining of copper
Industrial inorganic and organic chemicals
Nonferrous metal ores, except copper
Paper and paperboard mills
The rest
Total
Contribution
35%
15%
6%
6%
5%
3%
2%
2%
2%
2%
22%
100%
H-28
-------
Rank
1
2
3
4
5
6
7
8
9
10
Marine aquatic ecotoxicity
Electric services (utilities)
Brick and structural clay tile
Primary aluminum
Glass and glass products, except containers
Ceramic wall and floor tile
Sanitary services, steam supply, and irrig...
Coal
Industrial inorganic and organic chemicals
Primary metal products, n.e.c.
Plastics materials and resins
The rest
Total
Contribution
29%
27%
20%
2%
2%
2%
2%
1%
1%
1%
13%
100%
Terrestrial ecotoxicity
Cotton
Copper ore
Feed grains
Sanitary services, steam supply, and irrig...
Primary smelting and refining of copper
Miscellaneous crops
Paper and paperboard mills
Industrial inorganic and organic chemicals
Nonferrous metal ores, except copper
Primary aluminum
The rest
Total
Contribution
24%
10%
10%
5%
4%
4%
3%
3%
3%
3%
31%
100%
Freshwater sedimental ecotoxicity
Electric services (utilities)
Brick and structural clay tile
Primary aluminum
Copper ore
Glass and glass products, except containers
Sanitary services, steam supply, and irrig...
Ceramic wall and floor tile
Industrial inorganic and organic chemicals
Paper and paperboard mills
Plastics materials and resins
The rest
Total
Contribution
26%
24%
18%
3%
2%
2%
2%
2%
2%
2%
18%
100%
Rank
1
2
3
4
5
6
7
8
9
10
Marine sedimental ecotoxicity
Paper and paperboard mills
Industrial inorganic and organic chemicals
Pulp mills
Primary aluminum
Photographic equipment and supplies
Cut stone and stone products
Plastics materials and resins
Gum and wood chemicals
Primary nonferrous metals, n.e.c.
Synthetic rubber
The rest
Total
Contribution
12%
11%
9%
8%
7%
7%
6%
3%
3%
3%
30%
100%
Photochemical oxidation
Electric services (utilities)
Trucking and courier services, except air
Blastfurnaces and steel mills
Sanitary services, steam supply, and irrigation
Cement, hydraulic
Primary aluminum
Miscellaneous repair shops
Industrial inorganic and organic chemicals
Crude petroleum and natural gas
Clay refractories
The rest
Total
Contribution
14%
10%
10%
4%
4%
3%
2%
2%
2%
2%
48%
100%
Acidification
Electric services (utilities)
Cement, hydraulic
Blastfurnaces and steel mills
Trucking and courier services, except air
Primary aluminum
Primary smelting & refining of copper
Industrial inorganic and organic chemicals
Railroads and related services
Paper and paperboard mills
Crude petroleum and natural gas
The rest
Total
Contribution
42%
10%
9%
3%
3%
3%
2%
2%
2%
2%
21%
100%
Rank
1
2
3
4
5
6
7
8
9
10
Eutrophication
Electric services (utilities)
Trucking and courier services, except air
Cement, hydraulic
Railroads and related services
Cotton
Blastfurnaces and steel mills
Miscellaneous crops
Feed grains
Natural gas transportation
Industrial inorganic and organic chemicals
The rest
Total
Contribution
16%
8%
8%
5%
5%
5%
5%
4%
3%
2%
41%
100%
Energy consumption
Electric services (utilities)
Blastfurnaces and steel mills
Trucking and courier services, except air
Paper and paperboard mills
Wholesale trade
Air transportation
Sawmills and planing mills, general
Retail trade, except eating and drinking
Petroleum refining
Cement, hydraulic
The rest
Total
Contribution
31%
20%
5%
3%
3%
2%
2%
1%
1%
1%
32%
100%
Water consumption
Electric services (utilities)
Feed grains
Blastfurnaces and steel mills
Industrial inorganic and organic chemicals
Sanitary services, steam supply, and irrig...
Paper and paperboard mills
Cotton
Iron and ferroalloy ores, and misc. metal ores...
Petroleum refining
Trucking and courier services, except air
The rest
Total
Contribution
95%
1%
1%
0%
0%
0%
0%
0%
0%
0%
1%
100%
H-29
-------
Abiotic depletion
Landuse
Global warming
Dairy farm
products,4%
^
Ozone layer depletion
Human toxicity
Freshwater aquatic ecotoxicity
Miscellaneous
plastics
products, n.e.c.,
2%
Scrap, 2%
Pipe,valves,
and pipe Miscellaneous
fittings, 5% repairshops,
5%
Primary
nonferrous
metals, n.e.c.,
5%
Plastics
materials and
resins, 5%
Pulp mills, 4%
BrickandJ Paperand
structural clay paperboard
tile, 4%
Electric services
utilities), 6%
.Nonmetallic
Nonferrous mineral
metal ores, products, n.e.c.,
exceptcopper, 5%
Nonferrous
metal ores,
except copper,
2%
Industrial
inorganic and
Primary Or8anic
smelting chemicals, 2%
and refining
of copper,
2%
Figure H-B5a. Detailed output contribution analysis for new commercial building construction
H-30
-------
Marine aquatic ecotoxicity
Plastics
Primary metal materials and
products,n.e.c., Resins, 1%
1%.
Terrestrial ecotoxicity
Freshwater sedimental ecotoxicity
Nonferrous
metal ores,
except copper,
3%
crops, 4%
Marine sedimental ecotoxicity
Photochemical oxidation
Trucking and
courier services,
except air, 10%
Synthetic
rubber,3%
Primary _
nonferrous
metals, n.e.c.,
3%
Gum and wood
chemicals, 3%
materials and
resins,6%
_Photographic
_Cut stone equipment and
and stone supplies, 7%
products, 7%
petroleumand inorganic and
natural gas, 2% organic
chemicals, 2%
Primary
_aluminum, 3%
_Miscellaneous
repair shops,
2%
Sanitary
services, steam
supply, and
irrigation
systems, 2%
Glass and glass
products,
except
containers, 2%
Acidification
Paper and
paperboard
mills, 2%,
Crude
petroleumand
natural gas, 2%
(ji uuui.u, i in LliemiLdllj, Z.70
Figure H-B5b. Detailed output contribution analysis for new commercial building construction
H-31
-------
Eutrophication
Energy consumption
Water consumption
Trucking and
:ourierservices,
except air, 8%
Industrial
inorganic and _
organic . . . .
chemicals,2% Natural gas Miscellaneous LBlast
transportation, crops,5% furnaces Rai|roac|s and
3% I and steel re|ated services,
Feed grains, 4% mi||S; 5% %
Retail trade,
excepteating Sawi
and drinking, plan
1% Air
transportation,
2%
mills, 3% courierservices,
exceptair, 5%
Figure H-B5c. Detailed output contribution analysis for new commercial building construction
H-32
-------
APPENDIX H-C
CONTRIBUTION ANALYSIS RESULTS BY IMPACT CATEGORY
H-33
-------
Table H-C1
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Abiotic Depletion
Rank in 2020 Vision Analysis relative to Abiotic Depletion (final consumption): 15
Scope Analysis:
• Scope 1 (contribution of on-site activities to Abiotic Depletion):
• Scope 2 (contribution of electricity supplied to the site to Abiotic Depletion):
• Scope 3 (contribution of all other inputs to Abiotic Depletion):
0%
2%
98%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 1 %
Transportation of goods and materials to site 10%
Energy and utilities delivered to site 3%
Manufactured goods used in construction 79%
Construction-related services 8%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Prefabricated metal buildings and components 5%
Engineering, architectural, and surveying 4%
Motor vehicles and passenger car bodies 4%
Fabricated structural metal 4%
Retail trade, except eating and drinking 4%
Pipe, valves, and pipe fittings 3%
Wholesale trade 3%
Miscellaneous structural metal work 3%
Sheet metal work 3%
Petroleum refining 3%
The rest 64%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs
Transportation to produce direct inputs
Energy and utilities used to produce direct
inputs
Intermediate manufacturing
Services used to produce direct inputs
Direct impacts during construction
Top 10 contributing processes (and contribution):
Crude petroleum and natural gas
Coal
Petroleum refining
The rest
98%
0%
0%
2%
0%
0%
49%
49%
2%
0%
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services contributing to Abiotic
Depletion impacts in the 2020 Vision Relative Ranking Analysis.
• Almost all of the Abiotic depletion impacts associated with commercial building construction are embodied in the
materials, products, and services, including transportation, employed in commercial building construction, rather than
direct impacts during construction.
• From an input perspective, Abiotic Depletion impacts are widely distributed across inputs to commercial building
construction, with fabricated metal products contributing most significantly to the impacts.
• From an output perspective, Abiotic Depletion impacts are concentrated in petroleum, natural gas, and coal sectors.
H-34
-------
Table H-C2
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Land Use
(Increase of Land Competition)
Rank in 2020 Vision Analysis relative to Land Use (final consumption): >20
Scope Analysis:
• Scope 1 (contribution of on-site activities to Land Use):
• Scope 2 (contribution of electricity supplied to the site to Land Use):
• Scope 3 (contribution of all other inputs to Land Use):
0%
0%
100%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 20%
Transportation of goods and materials to site 12%
Energy and utilities delivered to site 0%
Manufactured goods used in construction 60%
Construction-related services 9%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Feed grains 19%
Sawmills and planing mills, general 8%
Trucking and courier services, except air 6%
Veneer and plywood 4%
Motor vehicles and passenger car bodies 4%
Millwork 3%
Engineering, architectural, and surveying 3%
Wholesale trade 3%
Eating and drinking places 2%
Retail trade, except eating and drinking 2%
The rest 46%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs
Transportation to produce direct inputs
Energy and utilities used to produce direct
inputs
Intermediate manufacturing
Services used to produce direct inputs
Direct impacts during construction
Top 10 contributing processes (and contribution):
Feed grains
Trucking and courier services, except air
Meat animals
Food grains
Poultry and eggs
Agricultural, forestry, and fishery services
Miscellaneous livestock
Cotton
Miscellaneous crops
Dairy farm products
The rest
Summary:
83%
17%
1%
0%
0%
0%
26%
15%
10%
8%
7%
6%
6%
5%
5%
4%
6%
• Commercial building construction was not ranked among the top 20 materials, products, and services contributing to
Land Use impacts in the 2020 Vision Relative Ranking Analysis.
• To the extent that commercial building construction contributes to competition for land, the contribution analyses
that the nature of the impacts are primarily associated with the use of land for agriculture and forestry.
suggest
• Impacts arise through the direct demand for raw materials and processed agricultural and forestry products in building
construction and the use of these materials and products in the transportation industry supply chain.
H-35
-------
Table H-C3
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Global Warming
(GWP 100)
Rank in 2020 Vision Analysis relative to Global Warminq (final consumption): 14
Scope Analysis:
• Scope 1 (contribution of on-site activities to Global Warming): 22%
• Scope 2 (contribution of electricity supplied to the site to Global Warming): 1 %
• Scope 3 (contribution of all other inputs to Global Warming): 76%
Contribution Analyses
Input Contribution Analysis
Aggregated Categories:
Raw materials used in construction 1 %
Transportation of goods and materials to site 7%
Energy and utilities delivered to site 3%
Manufactured goods used in construction 61 %
Construction-related services 6%
Direct impacts during construction 22%
Top 10 contributing processes (and contribution):
Prefabricated metal buildings and components 5%
Cement, hydraulic 4%
Ready-mixed concrete 4%
Motor vehicles and passenger car bodies 4%
Engineering, architectural, and surveying 4%
Fabricated structural metal 4%
Pipe, valves, and pipe fittings 3%
Retail trade, except eating and drinking 3%
Wholesale trade 3%
Miscellaneous structural metal work 3%
The rest 63%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs 5%
Transportation to produce direct inputs 6%
Energy and utilities used to produce direct 20%
inputs
Intermediate manufacturing 43%
Services used to produce direct inputs 2%
Direct impacts during construction 22%
Top 10 contributing processes (and contribution):
Electric services (utilities) 21 %
Blast furnaces and steel mills 15%
Cement, hydraulic 7%
Sanitary services, steam supply, and irrigation 4%
systems
Trucking and courier services, except air 4%
Crude petroleum and natural gas 3%
Air transportation 2%
Coal 1%
Petroleum refining 1%
Lime 1%
The rest 40%
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services contributing to Global
Warming impacts in the 2020 Vision Relative Ranking Analysis.
• Global Warming impacts of commercial building construction primarily occur through two mechanisms: 1) during the
production of manufactured goods used in construction; and 2) through direct emissions during on-site construction.
• From an input perspective, life-cycle Global Warming impacts are widely distributed across direct inputs to construction,
with impacts concentrated in two areas: 1) fabricated metal products and 2) cement and concrete.
• Shifts from the input to output perspective indicate that the Global Warming impacts of manufactured goods used in
commercial building construction include a significant contribution from embodied emissions associated with the energy
used in their production (e.g., electricity, blast furnaces and steel mills).
H-36
-------
Table H-C4
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Ozone Layer Depletion
(ODP Steady State)
Rank in 2020 Vision Analysis relative to Ozone Layer Depletion (final consumption): 9
Scope Analysis:
• Scope 1 (contribution of on-site activities to Ozone Layer Depletion): 0%
• Scope 2 (contribution of electricity supplied to the site to Ozone Layer Depletion): 0%
• Scope 3 (contribution of all other inputs to Ozone Layer Depletion): 100%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 0%
Transportation of goods and materials to site 4%
Energy and utilities delivered to site 0%
Manufactured goods used in construction 89%
Construction-related services 6%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Cut stone and stone products 1 1 %
Pipe, valves, and pipe fittings 7%
Misc. plastics products 5%
Metal doors, sash, frames, molding, and trim 5%
Motor vehicles and passenger car bodies 4%
Paints and allied products 4%
Prefabricated metal buildings and components 4%
Sheet metal work 3%
Nonferrous wiredrawing and insulating 3%
Lighting fixtures and equipment 3%
The rest 53%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs 0%
Transportation to produce direct inputs 0%
Energy and utilities used to produce direct 0%
inputs
Intermediate manufacturing 92%
Services used to produce direct inputs 7%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Industrial inorganic and organic chemicals 20%
Primary aluminum 13%
Cut stone and stone products 1 0%
Plastics materials and resins 5%
Primary nonferrous metals, n.e.c. 5%
Miscellaneous repair shops 5%
Pipe, valves, and pipe fittings 5%
Synthetic rubber 4%
Scrap 2%
Miscellaneous plastics products, n.e.c. 2%
The rest 28%
Summary:
• Commercial building construction was ranked among the top 10 materials, products, and services contributing to Ozone
Layer Depletion impacts in the 2020 Vision Relative Ranking Analysis.
• Ozone Layer Depletion impacts of commercial building construction primarily result from the production of manufactured
goods used in construction, with relatively significant contributions from transportation and construction-related services.
• From an input perspective, Ozone Depletion impacts are associated with a diverse range of direct inputs, with the most
significant contributions from cut stone and stone products, fabricated metal products, and plastic products.
• The output analysis highlights the contributions of early supply chain processes, such as chemical manufacturing and
primary metal processing, associated with the direct inputs identified in the input analysis.
H-37
-------
Table H-C5
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Human Toxicity
(HTPoo)
Rank in 2020 Vision Analysis relative to Human Toxicitv (final consumption): 13
Scope Analysis:
• Scope 1 (contribution of on-site activities to Human Toxicity): 0%
• Scope 2 (contribution of electricity supplied to the site to Human Toxicity): 1 %
• Scope 3 (contribution of all other inputs to Human Toxicity): 99%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 0%
Transportation of goods and materials to site 5%
Energy and utilities delivered to site 1 %
Manufactured goods used in construction 88%
Construction-related services 5%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Nonferrous wiredrawing and insulating 6%
Pipe, valves, and pipe fittings 5%
Brick and structural clay tile 4%
Prefabricated metal buildings and components 4%
Motor vehicles and passenger car bodies 4%
Cut stone and stone products 4%
Metal doors, sash, frames, molding, and trim 3%
Sheet metal work 3%
Miscellaneous plastics products, n.e.c. 3%
Engineering, architectural, and surveying 3%
The rest 62%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs 1 6%
Transportation to produce direct inputs 1 %
Energy and utilities used to produce direct 7%
inputs
Intermediate manufacturing 75%
Services used to produce direct inputs 1 %
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Copper ore 9%
Primary aluminum 8%
Primary smelting and refining of copper 8%
Electric services (utilities) 6%
Industrial inorganic and organic chemicals 5%
Nonmetallic mineral products, n.e.c. 5%
Nonferrous metal ores, except copper 5%
Paper and paperboard mills 5%
Brick and structural clay tile 4%
Pulp mills 4%
The rest 41%
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services contributing to Human
Toxicity impacts in the 2020 Vision Relative Ranking Analysis.
• Human Toxicity impacts of commercial building construction primarily result from the production of manufactured goods
used in construction, with relatively significant contributions from transportation and construction-related services.
• From an input perspective, Human Toxicity impacts are associated with a diverse range of direct inputs, with the most
significant contributions from fabricated metal products, stone, brick, and clay, and plastic products.
• The output analysis indicates diverse contributions from early supply chain processes with significant contributions from
the mining and metal processing, chemical, minerals, and paper manufacturing sectors.
H-38
-------
Table H-C6
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Freshwater Aquatic Ecotoxicity
(FAETPoo)
Rank in 2020 Vision Analysis relative to Freshwater Aquatic Ecotoxicitv (final consumption): >20
Scope Analysis:
• Scope 1 (contribution of on-site activities to Freshwater Aquatic Ecotoxicity):
• Scope 2 (contribution of electricity supplied to the site to Freshwater Aquatic Ecotoxicity):
• Scope 3 (contribution of all other inputs to Freshwater Aquatic Ecotoxicity):
0%
0%
100%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 1 1 %
Transportation of goods and materials to site 5%
Energy and utilities delivered to site 2%
Manufactured goods used in construction 76%
Construction-related services 6%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Feed grains 11%
Carpets and rugs 8%
Motor vehicles bodies 6%
Nonferrous wiredrawing and insulating 3%
Pipe, valves, and pipe fittings 3%
Miscellaneous plastics products, n.e.c. 3%
Prefabricated metal buildings and components 2%
Wholesale trade 2%
Engineering, architectural, and surveying 2%
Paints and allied products 2%
The rest 56%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs
Transportation to produce direct inputs
Energy and utilities used to produce direct
inputs
Intermediate manufacturing
Services used to produce direct inputs
Direct impacts during construction
Top 10 contributing processes (and contribution):
Cotton
Feed grains
Miscellaneous crops
Copper ore
Sanitary services, steam supply, and irrigation
systems
Agricultural, forestry, and fishery services
Primary smelting and refining of copper
Industrial inorganic and organic chemicals
Nonferrous metal ores, except copper
Paper and paperboard mills
The rest
Summary:
70%
0%
5%
23%
1%
0%
35%
15%
6%
6%
5%
3%
2%
2%
2%
2%
22%
• Commercial building construction was not ranked among the top 20 materials, products, and services contributing to
Freshwater Aquatic Ecotoxicity impacts in the 2020 Vision Relative Ranking Analysis.
• To the extent that commercial building construction contributes to Freshwater Aquatic Toxicity, the contribution
analyses
suggest that the nature of the impacts are primarily associated with agricultural run-off and wastewater discharges from a
variety of sectors.
H-39
-------
Table H-C7
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Marine Aquatic Ecotoxicity
(MAETPoo)
Rank in 2020 Vision Analysis relative to Marine Aquatic Ecotoxicitv (final consumption): 10
Scope Analysis:
• Scope 1 (contribution of on-site activities to Marine Aquatic Ecotoxicity): 0%
• Scope 2 (contribution of electricity supplied to the site to Marine Aquatic Ecotoxicity): 3%
• Scope 3 (contribution of all other inputs to Marine Aquatic Ecotoxicity): 97%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 0%
Transportation of goods and materials to site 5%
Energy and utilities delivered to site 3%
Manufactured goods used in construction 86%
Construction-related services 6%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Brick and structural clay tile 25%
Metal doors, sash, frames, molding, and trim 5%
Prefabricated metal buildings and components 4%
Motor vehicles and passenger car bodies 3%
Sheet metal work 3%
Engineering, architectural, and surveying 3%
Retail trade, except restaur. 3%
Pipe, valves, and pipe fittings 3%
Electric services (utilities) 3%
Ceramic wall and floor tile 2%
The rest 47%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs 4%
Transportation to produce direct inputs 0%
Energy and utilities used to produce direct 31 %
inputs
Intermediate manufacturing 65%
Services used to produce direct inputs 0%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Electric services (utilities) 29%
Brick and structural clay tile 27%
Primary aluminum 20%
Glass and glass products, except containers 2%
Ceramic wall and floor tile 2%
Sanitary services, steam supply, and irrigation 2%
systems
Coal 2%
Industrial inorganic and organic chemicals 1 %
Primary metal products, n.e.c. 1%
Plastics materials and resins 1 %
The rest 13%
Summary:
• Commercial building construction was ranked among the top 10 materials, products, and services contributing to Marine
Aquatic Ecotoxicity impacts in the 2020 Vision Relative Ranking Analysis.
• Marine Aquatic Ecotoxicity impacts of commercial building construction primarily result from the production of
manufactured goods used in construction, with relatively significant contributions from upstream electricity generation,
transportation and construction-related services.
• The input contribution analysis indicates that 25% of the Marine Aquatic Ecotoxicity impacts are embodied in brick and
structural clay tile used in commercial building construction; fabricated metal products also show significant contributions.
• The output analysis again highlights the contribution of brick and structural clay tile and suggests that much of the
embedded impacts associated with fabricated metal products are associated with aluminum processing.
H-40
-------
Table H-C8
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Terrestrial Ecotoxicity
(TETPoo)
Rank in 2020 Vision Analysis relative to Terrestrial Ecotoxicity (final consumption): >20
Scope Analysis:
• Scope 1 (contribution of on-site activities to Terrestrial Ecotoxicity):
• Scope 2 (contribution of electricity supplied to the site to Terrestrial Ecotoxicity):
• Scope 3 (contribution of all other inputs to Terrestrial Ecotoxicity):
0%
0%
100%
Contribution Analyses
Input Contribution Analysis
Output Contribution Analysis
Aggregated Categories:
Raw materials used in construction 7%
Transportation of goods and materials to site 5%
Energy and utilities delivered to site 2%
Manufactured goods used in construction 80%
Construction-related services 6%
Direct impacts during construction 0%
Aggregated Categories:
Raw materials used to produce direct inputs 55%
Transportation to produce direct inputs 0%
Energy and utilities used to produce direct 5%
inputs
Intermediate manufacturing 38%
Services used to produce direct inputs 1 %
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Feed grains 7%
Carpets and rugs 6%
Motor vehicles and passenger car bodies 5%
Nonferrous wiredrawing and insulating 5%
Pipe, valves, & pipe fittings 4%
Prefabricated metal buildings and components 3%
Misc. plastics products 3%
Wholesale trade 2%
Engineering, architectural, and surveying 2%
Metal doors, sash, frames, molding, and trim 2%
The rest 60%
Top 10 contributing processes (and contribution):
Cotton 24%
Copper ore 10%
Feed grains 10%
Sanitary services, steam supply, and irrigation 5%
systems
Primary smelting and refining of copper 4%
Miscellaneous crops 4%
Paper and paperboard mills 3%
Industrial inorganic and organic chemicals 3%
Nonferrous metal ores, except copper 3%
Primary aluminum 3%
The rest 31%
Summary:
• Commercial building construction was not ranked among the top 20 materials, products, and services contributing to
Terrestrial Ecotoxicity impacts in the 2020 Vision Relative Ranking Analysis.
• To the extent that commercial building construction contributes to Terrestrial Ecotoxicity, the contribution analyses
suggest that the nature of the impacts are primarily associated with agricultural run-off and wastewater discharges from a
variety of sectors.
H-41
-------
Table H-C9
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Freshwater Sedimental Ecotoxicity
(FSETPoo)
Rank in 2020 Vision Analysis relative to Freshwater Sedimental Ecotoxicitv (final consumption): 10
Scope Analysis:
• Scope 1 (contribution of on-site activities to Freshwater Sedimental Ecotoxicity):
• Scope 2 (contribution of electricity supplied to the site to Freshwater Sedimental Ecotoxicity):
• Scope 3 (contribution of all other inputs to Freshwater Sedimental Ecotoxicity):
0%
2%
98%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 0%
Transportation of goods and materials to site 5%
Energy and utilities delivered to site 3%
Manufactured goods used in construction 86%
Construction-related services 6%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Brick and structural clay tile 22%
Metal doors, sash, frames, molding, and trim 5%
Prefabricated metal buildings and components 4%
Motor vehicles and passenger car bodies 3%
Sheet metal work 3%
Engineering, architectural, and surveying 3%
Pipe, valves, and pipe fittings 3%
Nonferrous wiredrawing and insulating 3%
Retail trade, except eating and drinking 3%
Glass and glass products, except containers 2%
The rest 50%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs
Transportation to produce direct inputs
Energy and utilities used to produce direct
inputs
Intermediate manufacturing
Services used to produce direct inputs
Direct impacts during construction
Top 10 contributing processes (and contribution):
Electric services (utilities)
Brick and structural clay tile
Primary aluminum
Copper ore
Glass and glass products, except containers
Sanitary services, steam supply, and irrigation
systems
Ceramic wall and floor tile
Industrial inorganic and organic chemicals
Paper and paperboard mills
Plastics materials and resins
The rest
6%
0%
28%
66%
1%
0%
26%
24%
18%
3%
2%
2%
2%
2%
2%
2%
18%
Summary:
• Commercial building construction was ranked among the top 10 materials, products, and services contributing to
Freshwater Sedimental Ecotoxicity impacts in the 2020 Vision Relative Ranking Analysis.
• Freshwater Sedimental Ecotoxicity impacts of commercial building construction primarily result from the production of
manufactured goods used in construction, with relatively significant contributions from upstream electricity generation,
transportation and construction-related services.
• The input contribution analysis indicates that 22% of the Freshwater Sedimental Ecotoxicity impacts are embodied in
brick and structural clay tile; fabricated metal products also show significant contributions.
• The output analysis again highlights the contribution of brick and structural clay tile and suggests that much of the
embedded impacts associated with fabricated metal products are associated with aluminum processing.
H-42
-------
Table H-C10
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Marine Sedimental Ecotoxicity
(MSETPoo)
Rank in 2020 Vision Analysis relative to Marine Sedimental Ecotoxicity (final consumption): 14
Scope Analysis:
• Scope 1 (contribution of on-site activities to Marine Sedimental Ecotoxicity):
• Scope 2 (contribution of electricity supplied to the site to Marine Sedimental Ecotoxicity):
• Scope 3 (contribution of all other inputs to Marine Sedimental Ecotoxicity):
0%
0%
100%
Contribution Analyses
Input Contribution Analysis
Output Contribution Analysis
Aggregated Categories:
Raw materials used in construction 1 %
Transportation of goods and materials to site 6%
Energy and utilities delivered to site 0%
Manufactured goods used in construction 85%
Construction-related services 7%
Direct impacts during construction 0%
Aggregated Categories:
Raw materials used to produce direct inputs 1 %
Transportation to produce direct inputs 0%
Energy and utilities used to produce direct 0%
inputs
Intermediate manufacturing 97%
Services used to produce direct inputs 2%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Cut stone and stone products 7%
Miscellaneous plastics products, n.e.c. 5%
Motor vehicles and passenger car bodies 4%
Wholesale trade 4%
Engineering, architectural, and surveying 3%
Paints and allied products 3%
Metal doors, sash, frames, molding, and trim 3%
Photographic equipment and supplies 3%
Prefabricated metal buildings and components 3%
Lighting fixtures and equipment 3%
The rest 62%
Top 10 contributing processes (and contribution):
Paper and paperboard mills 12%
Industrial inorganic and organic chemicals 11 %
Pulp mills 9%
Primary aluminum 8%
Photographic equipment and supplies 7%
Cut stone and stone products 7%
Plastics materials and resins 6%
Gum and wood chemicals 3%
Primary nonferrous metals, n.e.c. 3%
Synthetic rubber 3%
The rest 30%
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services contributing to Marine
Sedimental Ecotoxicity impacts in the 2020 Vision Relative Ranking Analysis.
• Marine Sedimental Ecotoxicity impacts of commercial building construction result from the production of manufactured
goods used in construction, with relatively significant contributions from transportation and construction-related services.
• From an input perspective, Marine Sedimental Ecotoxicity impacts are associated with a diverse range of inputs, with the
most significant contributions from cut stone and stone, plastic, paint, and fabricated metal products.
• The output analysis highlights the contributions of early supply chain processes associated with the direct inputs
identified in the input analysis; it also highlights a concentration of impacts associated with paper/paperboard products
that is not reflected in the input analysis, suggesting that these early supply chain impacts are widely distributed among
direct inputs.
H-43
-------
Table H-C11
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Photochemical Oxidation
(NOx)
Rank in 2020 Vision Analysis relative to Photochemical Oxidation (final consumption): 15
Scope Analysis:
• Scope 1 (contribution of on-site activities to Photochemical Oxidation): 20%
• Scope 2 (contribution of electricity supplied to the site to Photochemical Oxidation): 1 %
• Scope 3 (contribution of all other inputs to Photochemical Oxidation): 79%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 1 %
Transportation of goods and materials to site 9%
Energy and utilities delivered to site 2%
Manufactured goods used in construction 62%
Construction-related services 7%
Direct impacts during construction 20%
Top 10 contributing processes (and contribution):
Trucking and courier services, except air 5%
Prefabricated metal buildings and components 4%
Motor vehicles and passenger car bodies 4%
Engineering, architectural, and surveying 4%
Ready-mixed concrete 3%
Pipe, valves, and pipe fittings 3%
Fabricated structural metal 3%
Wholesale trade 3%
Retail trade, except eating and drinking 3%
Cement, hydraulic 3%
The rest 65%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs 4%
Transportation to produce direct inputs 1 1 %
Energy and utilities used to produce direct 15%
inputs
Intermediate manufacturing 45%
Services used to produce direct inputs 5%
Direct impacts during construction 20%
Top 10 contributing processes (and contribution):
Electric services (utilities) 14%
Trucking and courier services, except air 10%
Blast furnaces and steel mills 10%
Sanitary services, steam supply, and irrigation 4%
Cement, hydraulic 4%
Primary aluminum 3%
Miscellaneous repair shops 2%
Industrial inorganic and organic chemicals 2%
Crude petroleum and natural gas 2%
Clay refractories 2%
The rest 48%
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services contributing to
Photochemical Oxidation impacts in the 2020 Vision Relative Ranking Analysis.
• Photochemical Oxidation impacts of commercial building construction primarily occur through two mechanisms: 1) during
the production of manufactured goods used in construction; and 2) through direct emissions during on-site construction.
• From an input perspective, life-cycle Photochemical Oxidation impacts are widely distributed across direct inputs,
including inputs associated with fabricated metal products, cement and concrete, and transportation and construction-
related services.
• Shifts from the input to output perspective indicate that the Photochemical Oxidation impacts include significant
contributions from embodied emissions associated with the energy used in manufacturing inputs and from transportation
emissions.
H-44
-------
Table H-C12
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Acidification
(including fate, average Europe total, A&B)
Rank in 2020 Vision Analysis relative to Acidification (final consumption): 12
Scope Analysis:
• Scope 1 (contribution of on-site activities to Acidification):
• Scope 2 (contribution of electricity supplied to the site to Acidification):
• Scope 3 (contribution of all other inputs to Acidification):
7%
3%
90%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 0%
Transportation of goods and materials to site 9%
Energy and utilities delivered to site 4%
Manufactured goods used in construction 72%
Construction-related services 8%
Direct impacts during construction 7%
Top 10 contributing processes (and contribution):
Cement, hydraulic 6%
Engineering, architectural, and surveying 5%
Ready-mixed concrete 5%
Prefabricated metal buildings and components 4%
Motor vehicles and passenger car bodies 4%
Retail trade, except eating and drinking 4%
Electric services (utilities) 4%
Pipe, valves, and pipe fittings 3%
Wholesale trade 3%
Fabricated structural metal 3%
The rest 59%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs
Transportation to produce direct inputs
Energy and utilities used to produce direct
inputs
Intermediate manufacturing
Services used to produce direct inputs
Direct impacts during construction
Top 10 contributing processes (and contribution):
Electric services (utilities)
Cement, hydraulic
Blastfurnaces and steel mills
Trucking and courier services, except air
Primary aluminum
Primary smelting & refining of copper
Industrial inorganic and organic chemicals
Railroads and related services
Paper and paperboard mills
Crude petroleum and natural gas
The rest
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services contributing to
Acidification impacts in the 2020 Vision Relative Ranking Analysis.
• Acidification impacts of commercial building construction primarily occur through two mechanisms: 1) during the
production of manufactured goods used in construction; and 2) through direct emissions during on-site construction
from emissions from construction equipment).
2%
6%
41%
42%
1%
7%
42%
10%
9%
3%
3%
3%
2%
2%
2%
2%
21%
(e.g.,
• From an input perspective, life-cycle Acidification impacts are widely distributed across direct inputs, with concentrated
contributions in two areas: 1) cement and concrete and 2) fabricated metal products.
• The output perspective indicates that the Acidification impacts include significant contributions from embodied emissions
associated with the energy used in manufacturing inputs.
H-45
-------
Table H-C13
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Eutrophication
(fate not included)
Rank in 2020 Vision Analysis relative to Eutrophication (final consumption): >20
Scope Analysis:
• Scope 1 (contribution of on-site activities to Eutrophication):
• Scope 2 (contribution of electricity supplied to the site to Eutrophication):
• Scope 3 (contribution of all other inputs to Eutrophication):
15%
1%
84%
Contribution Analyses
Input Contribution Analysis
Aqqreqated Categories:
Raw materials used in construction 3%
Transportation of goods and materials to site 9%
Energy and utilities delivered to site 2%
Manufactured goods used in construction 65%
Construction-related services 7%
Direct impacts during construction 15%
Top 10 contributing processes (and contribution):
Cement, hydraulic 5%
Ready-mixed concrete 4%
Motor vehicles and passenger car bodies 4%
Engineering, architectural, and surveying 4%
Trucking and courier services, except air 4%
Prefabricated metal buildings and components 4%
Feed grains 3%
Wholesale trade 3%
Retail trade, except eating and drinking 3%
Fabricated structural metal 3%
The rest 64%
Output Contribution Analysis
Aggregated Categories:
Raw materials used to produce direct inputs
Transportation to produce direct inputs
Energy and utilities used to produce direct
inputs
Intermediate manufacturing
Services used to produce direct inputs
Direct impacts during construction
Top 10 contributing processes (and contribution):
Electric services (utilities)
Trucking and courier services, except air
Cement, hydraulic
Railroads and related services
Cotton
Blastfurnaces and steel mills
Miscellaneous crops
Feed grains
Natural gas transportation
Industrial inorganic and organic chemicals
The rest
16%
14%
17%
36%
3%
15%
16%
8%
8%
5%
5%
5%
5%
4%
3%
2%
41%
Summary:
• Commercial building construction was not ranked among the top 20 materials, products, and services contributing to
Eutrophication impacts in the 2020 Vision Relative Ranking Analysis.
• To the extent that commercial building construction contributes to Eutrophication, the contribution analyses suggest that
site activities directly impact eutrophication, likely from site run-off.
• Impacts embedded in inputs to commercial building construction are primarily associated with cement and concrete,
fabricated metal products, transportation and construction services, and agricultural products.
H-46
-------
Table H-C14
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Energy Consumption
(mBTU)
Rank in 2020 Vision Analysis relative to Energy Consumption (final consumption): 13
Scope Analysis:
• Scope 1 (contribution of on-site activities to Energy Consumption):
• Scope 2 (contribution of electricity supplied to the site to Energy Consumption):
• Scope 3 (contribution of all other inputs to Energy Consumption):
6%
2%
91%
Contribution Analyses
Input Contribution Analysis
Output Contribution Analysis
Aggregated Categories:
Raw materials used in construction
Transportation of goods and materials to site
Energy and utilities delivered to site
Manufactured goods used in construction
Construction-related services
Direct impacts during construction
1%
11%
3%
71%
8%
6%
Aggregated Categories:
Raw materials used to produce direct inputs
Transportation to produce direct inputs
Energy and utilities used to produce direct
inputs
Intermediate manufacturing
Services used to produce direct inputs
Direct impacts during construction
2%
11%
30%
47%
4%
6%
Top 10 contributing processes (and contribution):
Prefabricated metal buildings and components 6%
Engineering, architectural, and surveying 5%
Retail trade, except eating and drinking 4%
Fabricated structural metal 4%
Motor vehicles and passenger car bodies 4%
Wholesale trade 4%
Pipe, valves, and pipe fittings 4%
Miscellaneous structural metal work 3%
Sheet metal work 3%
Electric services (utilities) 3%
The rest 62%
Top 10 contributing processes (and contribution):
Electric services (utilities) 31 %
Blast furnaces and steel mills 20%
Trucking and courier services, except air 5%
Paper and paperboard mills 3%
Wholesale trade 3%
Air transportation 2%
Sawmills and planing mills, general 2%
Retail trade, except eating and drinking 1 %
Petroleum refining 1%
Cement, hydraulic 1 %
The rest 32%
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services relative to Energy
Consumption in the 2020 Vision Relative Ranking Analysis.
• Energy Consumption associated with commercial building construction is primarily related to the production of
manufactured goods used in construction, though direct Energy Consumption during on-site construction is significant.
• From an input perspective, life-cycle Energy Consumption is widely distributed across direct inputs, with a concentration
of contributions in the areas of fabricated metal products and transportation and construction-related services.
• The output analysis shows significant contributions from embodied energy used in manufacturing inputs (51 % from
electric services and blast furnaces and steel mills) it also highlights a concentration of energy consumption associated
with wood products that is not reflected in the input analysis, suggesting that this consumption is widely distributed
among direct inputs.
H-47
-------
Table H-C15
Summary of Scope and Contribution Analyses
New Office, Industrial and Commercial Building Construction
Impact: Water Consumption
(gallons)
Rank in 2020 Vision Analysis relative to Water Consumption (final consumption): 14
Scope Analysis:
• Scope 1 (contribution of on-site activities to Water Consumption):
• Scope 2 (contribution of electricity supplied to the site to Water Consumption):
• Scope 3 (contribution of all other inputs to Water Consumption):
0%
8%
92%
Contribution Analyses
Input Contribution Analysis
Output Contribution Analysis
Aggregated Categories:
Raw materials used in construction 1 %
Transportation of goods and materials to site 12%
Energy and utilities delivered to site 8%
Manufactured goods used in construction 66%
Construction-related services 12%
Direct impacts during construction 0%
Aggregated Categories:
Raw materials used to produce direct inputs 2%
Transportation to produce direct inputs 0%
Energy and utilities used to produce direct 95%
inputs
Intermediate manufacturing 2%
Services used to produce direct inputs 0%
Direct impacts during construction 0%
Top 10 contributing processes (and contribution):
Electric services (utilities) 8%
Engineering, architectural, and surveying 8%
Retail trade, except eating and drinking 6%
Wholesale trade 4%
Motor vehicles and passenger car bodies 4%
Prefabricated metal buildings and components 4%
Pipe, valves, and pipe fittings 4%
Fabricated structural metal 3%
Miscellaneous plastics products, n.e.c. 2%
Sheet metal work 2%
The rest 55%
Top 10 contributing processes (and contribution):
Electric services (utilities) 95%
Feed grains 1%
Blast furnaces and steel mills 1 %
Industrial inorganic and organic chemicals 0%
Sanitary services, steam supply, and irrigation 0%
systems
Paper and paperboard mills 0%
Cotton 0%
Iron and ferroalloy ores, and miscellaneous metal 0%
ores, n.e.c.
Petroleum refining 0%
Trucking and courier services, except air 0%
The rest 1%
Summary:
• Commercial building construction was ranked among the top 15 materials, products, and services relative to Water
Consumption in the 2020 Vision Relative Ranking Analysis.
• Water Consumption associated with commercial building construction is related to the production of manufactured goods
used in construction and transportation and construction services.
• The output contribution analysis indicates that 95% of the Water Consumption associated with commercial building
construction is consumed in the generation of electricity used in manufacturing construction-related products and in
providing transportation and construction services.
H-48
-------
APPENDIX I - ENVIRONMENTAL JUSTICE AND EQUITY
I. Introduction
The link between affordability and Environmental Justice. The lack of housing opportunities in
new construction markets places low-income households in polluted environments where land is
cheap and environmental risks high. It also places them in older, existing structures where they are
more likely to be exposed to toxic building materials, mold and allergens. If new, green, healthy
homes are made affordable to low-income households, some of these injustices can be remedied.
In general, the cumulative upfront and running home-costs exceed the means of low-income
households or exhaust their spending on health care and education. However, there are distinct
opportunities to reduce these costs in green construction. For example, pursuing affordable, yet green
materials and managing construction waste can improve the builder's bottom line and be an effective
mechanism to lower the upfront costs for the owner; meanwhile, increasing energy efficiency can
reduce the homeowner's operational costs. Taking advantage of such opportunities can attain the
necessary balance between health and affordability to substantially benefit low-income households.
II. Reducing home costs
Taking a closer look, if developer profits are left out, upfront home costs will be comprised of
construction costs, costs of land and technical services. It is possible to reduce each. For example,
construction savings can be achieved through purchase of recycled and reused materials, construction
waste management and use of low-skill labor. Costs of land and technical services can be offset
through federal or local programs and grants, technical assistance and involvement of non-profits.2
Further, more substantial savings can always be achieved by taking advantage of economies of scale
and purchasing materials and labor in bulk, for several simultaneous low-income-home projects.
On the other hand, long-term housing costs will combine various costs of operating, maintaining
and/or renovating homes. Savings on energy bills can be achieved if design and construction
measures that optimize energy efficiency are combined with efficient lighting, appliances and
mechanical systems that reduce energy consumption. Costs of regular maintenance can be reduced
through purchases of recovered materials and construction waste management. Expenses on
adaptation and remodeling can be minimized if homes are designed to feature multifunctional,
adaptable, de-constructible spaces.
Recycled and Reused Materials
Reduce construction costs. As mentioned, the costs of construction and renovation can be reduced
through purchase of recycled and reused building materials. The market for recovered materials
primarily emerged from the growing awareness of the life cycle impacts of new building materials.
2 A number of case studies can be found at http://www.ncat.org/evergreen/evergreen_affordability_general.htm;
Evergreen Affordability is the product of the Affordable Sustainability Technical Assistance for HOME
(HomeASTA) project of the National Center for Appropriate Technology (NCAT), which was funded by the
U.S. Department of Housing and Urban Development.
-------
However, since recovered materials can function as financial assets to lower construction and
renovation costs for low-income-home builders and home-owners, their value extends beyond just
environmental protection. Pursuing affordable, sustainable materials can improve the builder's
bottom line and be an effective mechanism to lower the upfront home or renovation costs for the
owner.
Through virgin material extraction, manufacture into products, transportation and disposal, new
building materials take their share in the overall resource depletion, pollution and landfill
consumption. As consciousness of these impacts rises, jurisdictions are taking measures to tap into
construction and demolition waste as a massive, sustainable source of building materials. Materials
can be taken from waste streams, reprocessed and re-manufactured into recycled materials, or they
can be cleaned up and/or refmished, adapted by cutting to size and reused. Different tools such as
local regulatory measures, increases in disposal fees, education and green building are being used to
drive the market toward building material recovery. As an example, certain jurisdictions are now
requiring construction firms to perform waste stream audits. Materials that would in many cases just
be disposed of, are identified and salvaged.3 Such materials can become a source of low-cost
building material.
The Building Material Reuse Association recently gathered industry representatives together at its
2011 convention, Decon ' 11 to speak about the value of deconstruction and material reuse.
Participants included appraisers and reuse consultants and designers. One of the repeatedly mentioned
benefits supported by industry examples was that deconstruction provided sustainable, low-cost
building materials.4 Along the same lines, the City of Seattle's Department of Planning and
Development published that recycling or reusing salvaged building materials as well as minimizing
materials and packaging, reduces material expenses.5 Reduced material expenses translate into lower
upfront housing costs as well as lower renovation/maintenance costs.
Differences in cost that exist between various recycled and reused materials reflect the value added
through the recovery process. In limited cases, this difference can result in a higher cost for a
recycled or reused material. However, even in these limited cases, funding may be available through
the Low Income Housing Tax Credit program to offset this incremental cost. State and local
governments provide funds based on how many points from their Qualified Allocation Plans the
projects are able to meet. States allocate points for green building practices, and a number of them
allocate points for recycled/reused materials.6 In such a case, incorporating recovered materials may
3 Careers in Green Construction, Bureau of Labor Statistics, United States Department of Labor,
http://www.bls.gov/green/construction/. Accessed on August 11, 2011.
4 For more information and copies of presentation slides, please see http://www.bmra.org/about-
bmra/newsupdates/323-decon-ll-presentations-are-available .
5 Department of Planning and Development, City of Seattle, June 2005: Construction Waste Management Guide
for Architects, Designers, Developers, Facility Managers, Owners, Properly Managers & Specification Writers,
p.2.
http://www.seattle.gov/dpd/cms/groups/pan/(@.pan/(@.sustainableblding/documents/web informational/dpds 00
7173.pdf. August 11. 2011.
6 Global Green USA, http://www.globalgreen.org/greenurbanism/affordablehousing/. Accessed August 15,
2011
-------
help the project qualify for funding that would in turn help the project team afford more sustainable
material choices for the needed applications.
Support job creation and community revitalization. Incorporating recycled and reused materials
supports the recycling and reuse industry, which creates jobs.7 According to The U.S. Recycling
Economic Information Study, more than 56,000 recycling and reuse establishments in the United
States employ approximately 1.1 million people.8 Building materials recovery generally involves
substantial activities around deconstruction, sorting, salvage, value adding, stocking, and resale.
Therefore, the contribution of building material-recovery jobs to the overall recycling industry is
significant.
Equally significant is the fact that recovered materials are typically sourced locally and that therefore,
any associated economic activity should directly benefit local communities. These benefits range
from creating local deconstruction, recovery, or resale jobs and providing low-cost materials for local
residents, to creating tax revenues and revitalizing communities at large.
Reduce pollution associated with material disposal and new material production. Environmental
Justice benefits can be achieved through pollution reduction that is enabled by material recovery.
Material recovery diverts waste and intercepts the emissions associated with either the incineration or
the material break-down in landfills. In addition, the recovered materials replace raw materials or
finished products; thereby, the recovery intercepts the pollution associated with the extraction and
processing of virgin materials and the manufacture of new products.9 Even though the pollution
reduction improves the environment for all, benefits are greatest for disadvantaged, low-income
communities that are often in the closest proximity to waste and manufacturing facilities. These low-
income households typically face cumulative pollution risks as various waste and manufacturing
facilities are often grouped together.
Health and safety considerations. Although building material reuse and recovery affords needed
economic, social and environmental benefits to society, concerns regarding human health and safety
do exist. For example, with material reuse and recycling, potentially harmful materials that had
historically circulated in the construction and maintenance of buildings (e.g. lead-based paint) could
7 The Tellus Institute in its report More Jobs, Less Pollution: Growing the Recycling Economy in the U.S.,
compared two hypothetical 2030 waste management scenarios; the baseline scenario that was developed on
continuing current practices to reach about 37-percent C&D waste diversion by 2030, and the Green Economy
scenario reflecting 75-percent C&D diversion through significantly enhanced recycling and composting efforts.
The Green Economy scenario generated more than twice the amount of jobs of the baseline scenario
demonstrating that the recycling jobs gained through enhanced diversion outnumber any loss of jobs in C&D
waste disposal. In addition, in its study 2008 Employment Trends in N.C. 'S Recycling Industry, the state of
North Carolina looked at the recycling industry at large and found that job losses in waste disposal and virgin
materials mining and manufacture that directly result from recycling program success, in North Carolina, were
balanced or outweighed by job creation in the recycling sector.
8 U.S. EPA: http://waste.supportportal.com/link/portal/23002/23023/Article/18602/If-there-is-plentv-of-landfill-
space-then-why-should-I-recvcle. Accessed August, 12, 2011.
9 U.S. EPA, Is recycling worthwhile:
http://waste.supportportal.com/ics/support/kb Answer.asp?deptID=23023&task=knowledge&questionID=19159
, Accessed August 12, 2011.
1-3
-------
be reintroduced into the housing stock, if not properly managed. From an environmental justice
perspective, of those materials, particular attention has been given to lead-based paint. Fighting
childhood lead-based paint poisoning has become one of the Department of Housing and Urban
Development (HUD)'s primary environmental justice initiatives.10 Through this initiative, HUD
provides public outreach and technical assistance and conducts technical studies to help protect
children and their families from health and safety hazards in the home.n
The U.S EPA also works to promote safe reuse and has gathered useful information to communicate
these issues.12 For example, in its Pollution Prevention and Toxics website, the EPA specifically
addresses the question of how reuse stores and their customers can manage the lead-based paint in
older building materials. As a primary matter, the EPA notes that states may have laws or regulations
addressing the management, handling or sale of materials containing lead-based paint, which would
give very specific directions. Otherwise, the EPA recommends that reuse stores at a minimum label
suspect items to indicate that they may contain lead, educate staff about lead hazards, and provide
outreach materials to customers about lead-safe work practices. The EPA also lists useful resources.13
While lead has taken center stage, health and safety concerns may revolve around other materials and
products as well. Unsafe materials include asbestos, mercury, PCBs or arsenic.
It is also important to ensure that the chosen materials and products suit the application they are
intended to fill. For example, unless properly treated, salvaged lumber may not be suitable for
structural applications.14 Using recovered materials because of their low-cost, but without due regard
for functional suitability, could result in unsafe applications in affordable homes. Additionally, some
products may not be sufficiently efficient to provide healthy indoor conditions or long-term cost-
savings. For example, a single-pane window may be inexpensive and in usable condition, but
meanwhile, it is energy-inefficient in certain climates and thus, not a good, affordable thermal
solution for a home-owner in the long-run. However, such a window could still be used in interior
applications, e.g. as a transom, where it could allow penetration of light into secondary spaces such as
hallways. Using salvaged materials in certain applications might not meet the requirements of local
building codes and it is most practical and protective for builders and home-owners to consult local
building officials early.
10 U.S. Department of Housing and Urban Development, March 1995, Achieving Environmental Justice
- a Departmental Strategy:
http://www.hud.gov/offices/cpd/environment/librarv/subjects/iustice/deptstrategv.cfm#b. Accessed August 15,
2011.
11 U.S. Department of Housing and Urban Development, Healthy Homes and Lead Hazard Control,
http://portal.hud.gov/hudportal/HUD?src=/program offices/healthy homes. Accessed August 15, 2011.
12 U.S EPA, Pollution Prevention and Toxics, 2011: http://www.epa.gov/opptintr/. Accessed August 15,2011.
13 U.S EPA, Pollution Prevention and Toxics, 2011, Frequent Questions, General Information about Lead, 2011:
http://toxics.supportportal.com/link/portal/23002/23019/Article/32411/Building-material-reuse-stores-
sometimes-accept-older-materials-which-have-been-coated-with-lead-based-paint-and-could-pose-a-lead-
poisoning-hazard-In-particular-older-windows-and-doors-are-likely-to-. Accessed August 15, 2011.
14 King County Department of Natural Resources and Parks, Solid Waste Division & City of Seattle
Department of Planning and Development, 2006. {Green home remodel} salvage & reuse:
http://vour.kingcountv.gov/solidwaste/greenbuilding/documents/Green home remodel-salvage.pdf. Accessed
August 15, 2011.
1-4
-------
Therefore, builders and home-owners who purchase building products for reuse should select them
judiciously in order to capitalize on their lower cost without jeopardizing the health and/or safety of
home-occupants. In that respect, additional inquiries and/or inspections may be warranted around
certain types of materials.
Durability and maintenance. Interest in using recovered materials in new construction is not
uniformly present across the country. One common concern is that recycled or reused materials are
inferior in quality and may not be as durable. This perception is limiting the development of needed
infrastructure to increase the availability of these materials for affordable housing projects.
However, the U.S EPA has published that recycled materials contain similar chemical and physical
properties as the virgin materials they replace, and when used according to appropriate environmental
regulations engineering specifications, provide comparable—and in some cases, superior—
performance at a lower cost.15
The Department of Planning & Development of the City of Seattle and the Department of Natural
Resources and Parks of King County both advocate that salvaged materials cost less and last longer:
their longevity is especially evident when building materials are salvaged from the structures of the
periods that boasted construction of better quality.16
The USGBC consistently encourages the use of salvaged or reused building materials in single family
home construction. The USGBC does not specifically recommend any additional operations and
maintenance considerations pertaining to reused materials.17 However, the USGBC does point out
that the recycled-content materials may need different maintenance practices than conventional
products. Homeowners should be made aware of any specific maintenance requirements in order to
defer and minimize repairs. However, the USGBC's caution that recycled-content materials may
require specific upkeep should not be interpreted to imply that these materials would not last long or
perform as is expected. The performance requirements of building codes may on the outset determine
the expected levels of maintenance and durability for the materials that are alternative to
conventional. Accordingly, the recycled/reused product suppliers may warranty the product
performance to ensure a customer base. Such warranties might sufficiently address any concerns for
designers, builders and owners. In any case, designers, builders and developers must ensure that
salvaged materials meet applicable building codes and laws.
Planning considerations. If the process to include reclaimed materials is to be successful, so that any
benefits for low-income households could accrue, builders and homeowners should be aware that the
15 U.S. EPA, Office of Resource Conservation and Recovery, March 2009. Estimating 2003 Building Related
Construction and Demolition Materials Amounts, p. 21.
16 King County Department of Natural Resources and Parks, Solid Waste Division & City of Seattle
Department of Planning and Development, 2006. {Green home remodel} salvage & reuse:
http://vour.kingcountv.gov/solidwaste/greenbuilding/documents/Green home remodel-salvage.pdf. Accessed
August 15, 2011.
17 U.S. Green Building Council, Green Building Design and Construction, LEED Reference Guide for the
Design, Construction and Major Renovations of Commercial and Institutional Buildings Including Core and
Shell and K-12 School Projects, 2009 Edition (Updated June 2010), p. 367 and 375.
1-5
-------
construction process is not traditional and that additional planning steps are needed. Guidelines from
industry practitioners and local governments and technical assistance are available to make this
process more predictable. For example, considering that the material availability fluctuates,
guidelines suggest that it is necessary to keep a flexible design and schedule. Flexibility will allow the
designers/builders to investigate the market and capitalize on the safe, affordable materials as they
become available. However, because the prospective materials will not all come at the same time, the
designers/builders will need to provide spaces for their proper storage on-site. On the side of design
though, reliance on random local materials that are available during construction will most likely
result in unique structures and creative material patterns and applications18 that could be aesthetically
valuable in affordable housing.
Construction waste management
Savings on landfill fees. Another way to reduce construction and renovation costs and thereby the
housing costs is through construction waste management. Already, in locations in which disposal
fees are high, the clear opportunity for savings has facilitated the development of markets for material
recovery as an alternative to disposal;19 national trends suggest that such opportunities will become
widespread. Tipping fees are increasing, regulations are excluding C&D materials from landfills, and
the number of C&D landfills has declined 26% between 1990 and 2002.20 In 2003, Connecticut was
already running out of construction and demolition landfill capacity. Massachusetts was considering a
full disposal ban on certain construction and demolition waste materials, such as asphalt, concrete,
metal and wood.21 These examples illustrate fairly well how C&D waste disposal options may grow
fewer and more expensive in the future and support the idea that the savings from construction waste
management if only through the avoidance of landfill fees may become significant.
Material efficiency. Further, through construction waste management and reclamation of material
scraps, builders can use their primary materials more efficiently. In conventional building, builders
may pay for materials at the initial purchase, for the landfill fees at the disposal of material scraps that
are usable and again, at the unnecessary re-purchase.22 Conversely, by managing construction waste,
the builders will be able to fully capitalize on the scraps and wherever possible limit the expenditures
to only initial purchases.
Resale. Third, the builders may sell the materials salvaged through construction waste management to
create revenue; they may need to investigate the market to focus on materials and products with
18 Olivia Chen, Affordable Housing Made of Recycled Materials: http://inhabitat.com/low-income-housing-
made-of-recvcled-materials/. Accessed September 16, 2011.
19 U.S. EPA, Office of Resource Conservation and Recovery, March 2009. Estimating 2003 Building Related
Construction and Demolition Materials Amounts, p. 20.
20 Tom Napier, Construction Waste Management, 2011: http://www.wbdg.org/resources/cwmgmt.php.
Accessed August 17, 2011.
21 Gruzen Samton LLP with City Green Inc. for NYC Department of Design & Construction, May 2003;
Construction and Demolition Waste Manual: http://www.nvc.gov/html/ddc/downloads/pdf/waste.pdf. Accessed
August 18, 2011.
22 Adapted from NAHB Research Center, Residential Construction Waste: From Disposal to Management:
http://www.toolbase.org/Best-Practices/Construction-Waste/residential-construction-waste. Accessed August
17,2011.
1-6
-------
higher resale values and be especially careful to protect materials from any damage that may render
them undesirable. The changes in the construction demands and the limited stocking space may at
times make the resale more difficult, but it should still be possible to get in-store credit.23 The various
reclamation outlets include used building materials retailers, online exchanges, classified ads and
recycling companies.24
Incentive programs. Fourth, the builders may donate the materials salvaged through construction
waste management and receive tax breaks. Further, various government incentive programs reward
construction waste management efforts. For example, a number of states award a point toward Low
Income Housing Tax Credit funding for projects that implement construction waste management;25
construction waste management can help qualify for the funding.
In addition to local governments, non-profits may also provide grants or loans for green affordable
housing. One example is Enterprise Community Partners who have developed the Green
Communities criteria in collaboration with The Natural Resources Defense Council, American
Institute of Architects, American Planning Association, etc, to support the funding of affordable
projects decisions. The Green Communities criteria include two separate construction waste
management requirements and one is mandatory to secure the funding.26
Savings on hauling fees. Finally, builders who reduce the waste through construction waste
management also decrease the fees associated with its transportation to landfills. For example, by
2003, New York City had already run out of disposal facilities and had to export its waste.27 As more
landfills close and disposal options become fewer, average hauling distances will most likely
increase28 and raise the hauling fees. In comparison, salvaged materials are either reused on site or
can be self-hauled to local outlets.
As illustrated, construction waste management can reduce material costs in different ways: by
reducing disposal fees, initial material costs, by generating revenue through resale, through collecting
tax breaks or qualifying for funding and reducing hauling fees. However, since some of the savings
23 King County Department of Natural Resources and Parks, Solid Waste Division & City of Seattle
Department of Planning and Development, 2006; {Green home remodel} salvage & reuse:
http://vour.kingcountv.gov/solidwaste/greenbuilding/documents/Green home remodel-salvage.pdf. Accessed
August 15, 2011.
24 Ibid.
25 Global Green USA, http://www.globalgreen.org/greenurbanism/affordablehousing/. Accessed August 15,
2011
26 Enterprise Community Partners Inc, 2011 Enterprise Green Communities Criteria:
http://www.greencommunitiesonline.org/tools/criteria/EGC2011Criteria fmal.pdf. Accessed August 22, 2011
27 Gruzen Samton LLP with City Green Inc. for NYC Department of Design & Construction, May 2003;
Construction and Demolition Waste Manual: http://www.nvc.gov/html/ddc/downloads/pdf/waste.pdf. Accessed
August 18, 2011.
28 T.R. Napier, D.T. McKay, N.D. Mowry, 2007, A lifecycle perspective on recycling construction materials
(The most sustainable materials may be the ones we already have), International conference on Sustainable
Construction Materials and Technologies - Chun, Claisse, Naik & Ganijan (eds), Taylor & Francis Group,
London, ISBN 978-0-415-44689-1
1-7
-------
are contingent on market conditions, it may be necessary to first investigate the market to be able to
find the path of most savings.
When builders are not looking to generate revenues from selling construction waste, or the temporary
demand for particular materials is low and reuse businesses lack stocking space, the building
materials can be saved for future reuse. In such cases, builders will still avoid landfill fees and cost
savings can be transferred onto homeowners who would not have to repurchase the materials for the
future maintenance. For example, NAHB recommends such a savings track in case of flooring
sheets.29
Indirect Environmental Justice benefits. Because construction waste management and material
recovery are inextricably linked, they provide some of the same Environmental Justice benefits. In
brief, material salvaged through construction waste management serves as the source for the recycling
and reuse industry, and thus, supports the sector and its addition of low-skill jobs. Construction waste
management reduces the amount of waste sent to landfills and decreases potential sanitary and
environmental pollution associated with the break-down that most affects the surrounding low-
income households. Recovered materials replace virgin materials and intercept the new extraction and
manufacture and the associated industrial pollution that again, most affects the surrounding low-
income communities. In addition, the diversion of waste decreases the extent of needed landfill
management efforts that typically drain public funds.30 Reducing the landfill capping, closing and
monitoring efforts allows that such public funds be used toward national and state programs that may
directly benefit low-income households.
Planning considerations. The above examples note the ways in which construction waste
management can bring savings. However, even though construction waste management can be a
financially worthwhile undertaking and most residential construction waste is recyclable31, the
recovery opportunities may not exist or be obvious everywhere. The best way to explore their
availability or develop new opportunities is to draft local and state solid waste officials, product
manufacturers and recyclers and hold forums on existing opportunities or potential barriers and
obstacles.32
Further, even with opportunities in place, any savings from construction waste management are
contingent on timely planning. The key actions include finding salvage and recycle companies,
identifying appropriate handling procedures and determining the best ways and time to haul the
29 NAHB Research Center, Residential Construction Waste: From Disposal to Management:
http://www.toolbase.org/Best-Practices/Construction-Waste/residential-construction-waste. Accessed August
17,2011.
30 T.R. Napier, D.T. McKay, N.D. Mowry, 2007, A lifecycle perspective on recycling construction materials
(The most sustainable materials may be the ones we already have), International conference on Sustainable
Construction Materials and Technologies - Chun, Claisse, Naik & Ganijan (eds), Taylor & Francis Group,
London, ISBN 978-0-415-44689-1
31 NAHB Research Center, Residential Construction Waste: From Disposal to Management:
http://www.toolbase.org/Best-Practices/Construction-Waste/residential-construction-waste. Accessed August
17,2011.
32 Ibid.
1-8
-------
material. Reuse businesses may have limited space and might change the selection of materials they'll
take, or processing facilities may only take sorted recyclable materials. Finding out such details early
enables timely preparation and successful efforts. For example, specific handling procedures may
introduce new on-site tasks such as materials sorting. Even if the separation is generally not very
difficult since materials are mostly used one at a time, which reduces the time and effort spent
sorting,33 the added task may require some level of preparation.
Design measures
Size and spatial form. Other cost savings opportunities exist in the application of certain design
decisions. For example, houses that are smaller all-around require less material input as well as fewer
equipment and labor hours to construct. In addition, compact houses that are built "up" instead of
"out" have smaller footprints that require less land and land preparation which translates into savings
on land acquisition, as well as equipment use and labor effort. In turn, these reduced resources during
construction reduce the upfront costs of a home. Design strategies that focus on reducing circulation
paths, filling spaces under roofs, sharing spaces between different uses, using built-in furniture, etc,
help achieve the needed spatial efficiency.
In addition, homeowners capitalize on using less energy to operate these smaller homes, and the
houses that are developed vertically instead of horizontally increase land-use density; if accompanied
by an appropriate mixing of land uses, the increased density allows homeowners to access various job
opportunities and commercial services easily and thus, save on transportation costs. Reduced energy
bills and transportation costs add up over life spans of homes.
Advanced Framing Techniques. Yet another distinct way to reduce construction and operational
costs is to use advanced framing techniques. Builders eliminate unnecessary framing without
compromising the homes' structural integrity and thus, use less material and labor in support of the
same structural performance. The U.S. Department of Energy has maintained detailed information
about advanced framing methods and has documented how fully implementing advanced framing
techniques in 2000 could have resulted in materials cost savings of about $500 or $1000 (for a 1,200-
and 2,400-square-foot house, respectively), and labor cost savings of between 3 and 5 %.34 In
addition, the reduced material input reduces the amount of waste that needs to be disposed of, which
improves the builders' bottom line even further; the reductions in material purchasing and labor
expenditures combine with the avoidance of landfill fees to create the full cost-savings amounts.
Savings to homeowners from implementing advanced framing techniques are accrued over the
lifespan of the homes. By replacing the framing not needed to support the homes' structural integrity
33 M. U. Christiansen, 2007, An analysis of environmental and fiscal impacts or recycling during Kern Center
construction, International conference on Sustainable Construction Materials and Technologies - Chun, Claisse,
Naik & Ganijan (eds), Taylor & Francis Group, London, ISBN 978-0-415-44689-1
34 U.S. Department of Energy, Energy Efficiency and Renewable Energy, Office of Building Technology, State
and Community Programs, October 2000; Advanced Wall Framing:
http://appsl.eere.energv.gov^uildings/publications/pdfs/building america/26449.pdf. Accessed August 22,
2011.
1-9
-------
with insulation materials, homebuilders are able to reduce the thermal bridging and increase the
homes' energy efficiency. In fact, the U.S. Department of Energy has documented how fully
implementing advanced framing techniques in 2000 could have resulted in annual heating and cooling
cost savings of up to 5 %.35
Advanced Framing Techniques - Applicability considerations. However, even though advanced
framing techniques have been proven effective, local codes might not allow them because of specific
local conditions, e.g. wind or seismic potential.36 The consulting of building officials may alert the
builders to any code restrictions and help them find the advanced framing technique options that are
the most suitable.
Open layouts. Similarly to how advanced framing techniques eliminate unnecessary framing, open
layouts exclude unnecessary walls. For example, walls could be fully or partially removed between
complementary spaces, such as dining and living rooms or corridors and day areas. Such open layouts
reduce material input and simplify future reconfiguration and thus, reduce material and labor costs
both initially and during future adaptations.
Reduced interior finishes. Eliminating interior finishes by relying on structural materials to double
as finishes where possible, can serve as another effective method to reduce construction costs. For
example, a stained or decorated concrete slab on grade can serve as a finished floor in kitchens or
bathrooms and replace the tile. Again, this strategy reduces both the material and labor costs.
The strategies noted above begin to illustrate ways in which home design can reduce home costs in
green construction. The list of strategies is not exhaustive.
Low Cost Professional Services, Technical Assistance and Labor
Green building design requires high-skill, specialized workforce that can streamline the design and
construction processes to reach the "green" affordability objectives and avoid potential pitfalls.
However, to limit the expense of green building professional services, a green building specialist can
be hired as a consultant to just a traditional design firm. Alternatively, local professionals who bring
to the table familiarity with the community and the site, connections to local manufacturers and
suppliers, ability to find best deals on construction materials, a passion to learn about sustainability,
willingness to tap into available technical resources but not necessarily the actual green building
experience, may present the best value yet. Various collections of detailed case studies may provide
additional guidance. For example, the U.S. Department of Housing and Urban Development has
funded the National Center for Appropriate Technology (NCAT) to develop the Affordable
Sustainability Technical Assistance for HOME (HomeASTA) project to help the recipients of HOME
35 Ibid.
36 Ibid.
1-10
-------
grants build green affordable housing projects. Under the HomeAsta project, the NCAT produced
Evergreen Affordability. The compiled case studies can be used as a resource.37
In contrast, many building construction trades can be learned through on-the-job training,38 which
raises an opportunity to employ a low-skill, low-cost workforce. For example, to build homes
inexpensively, Habitat for Humanity recruits homeowner families to invest hundreds of hours of
sweat equity. By involving future homeowners, Habitat for Humanity keeps the cost of labor down
and manages to limit the funding needs and to sell the houses to the partner families at low cost.39
Habitat for Humanity has used this building model to provide green affordable homes. In such a
model, the non-profit developer uses the homeowners' sweat equity but meanwhile trains the families
for free and equips them with sustainable building skills they may use for future jobs. In that respect,
such affordable green construction building model provides additional environmental justice benefits.
Cost of Land
In order to keep properties affordable for low-income households, it is also important to acquire land
at low cost. This is especially challenging when attempting to otherwise take advantage of economies
of scale and acquire several adjacent properties for simultaneous low-income housing projects.
However, building green gives access to a number of financial streams and incentives that can
partially offset these costs, and at times, developers have relied on city donated land and land trusts as
well.
Energy Efficiency
A yet another distinct way to reduce housing costs is to design homes with energy efficiency in mind.
Energy efficiency features such as passive solar design, well-insulated and well-sealed shells,
efficient HVAC equipment and appliances could combine with smaller sizes and advanced framing
techniques to deliver long-term savings on energy bills. For illustrative purposes, compared to
standard homes, Energy Star homes, which feature effective insulation, high-performance windows,
tight construction and ducts, efficient equipment and appliances, use substantially less energy for
home heating, cooling, and water heating and deliver $200 to $400 in annual savings on just these
40
expenses.
While some of the energy efficiency measures such as optimizing home-orientation or window size
and positioning may not come at additional costs, others, such as increasing the amount of insulation
37 National center for Appropriate Technology for U.S. HUD, Evergreen Affordability, Tools for Building
Sustainable Housing, 2004: http://www.neat.org/evergreen/evergreen affordabilitv general.htm. Accessed
August 22, 2011.
38 United States Department of Labor, Bureau of Labor Statistics, Green Jobs, Careers in Green Construction:
http://www.bls.gov/green/construction/. Accessed August 22, 2011.
39 Habitat for Humanity Fact Sheet, 2011: http://www.habitat.org/how/factsheet.aspx. Accessed September 16,
2011
40 ENERGY STAR, Features & Benefits of ENERGY STAR Qualified New Homes:
http://www.energystar.gov/index. cfm?c=newhomes.nh_features: Accessed September 19, 2011.
1-11
-------
or including more-efficient windows, may. However, Habitat for Humanity Metro Denver partnered
with the U.S Department of Energy's Building America Project and the National renewable Energy
Laboratory to create affordable, energy-efficient demonstration homes which shows that energy
efficiency features can be incorporated in cost-effective ways.41
III. Conclusion
An attempt to propose how to address the environmental risks of low-income families, led us to talk
about affordability of green housing. Currently, low-income households face environmental risks
because of the average quality and age of their housing. Our intent was to highlight the opportunities
for cost savings in new green construction and underline that the health benefits of green homes can
be extended to low-income groups to protect them from unnecessary environmental burdens.
In addition, some of the highlighted strategies resolve other Environmental Justice issues as well. For
example, construction waste management and material recovery also support the recycling and reuse
industry and its addition of low-skill jobs. The two strategies divert waste and decrease the potential
sanitary and environmental pollution associated with material break-down and/or incineration that
most affects the proximate low-income communities. Further, the waste diversion decreases the
magnitude of landfill capping, closing and monitoring efforts and the amount of public funding going
into it. The funding can then be streamed toward other efforts to further benefit low-income
communities. In addition, the construction waste management and recovery also limit the unnecessary
excavation and manufacturing and the pollution burdens and their effect on proximate communities
that are typically low-income.
41 Building America, U.S Department of Energy case studies: http://www.nrel.gov/docs/fy05osti/36102.pdfand
http://www.nrel.gov/docs/fy08osti/42591.pdf. Accessed September 19, 2011.
1-12
-------
0 CDA
R 1^ 004. \^tl *m
-K-1 J-UU^t United States
Environmental Protection
Agency
------- |