NISTIR 6520
BEES 2.0
Building for Environmental and Economic Sustainability
Technical Manual and User Guide
Barbara C. Lippiatt
With Support From:
U.S. Environmental Protection Agency
Office of Pollution Prevention and Toxics
and
U.S. Department of Housing and Urban Development
Partnership for Advancing Technology in Housing
MIST
National Institute of Standards and Technology
Technofogy Administration, U.S. Department of Commerce
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NISTIR 6520
BEES 2.0
Building for Environmental and Economic Sustainability
Technical Manual and User Guide
Barbara C. Lippiatt
Office of Applied Economics
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899-8603
June 2000
With Support From:
UsSt^d Stales
Enwronwenfa!
U.S. Environmental Protection Agency
Carol M. Browner, Administrator
Office of Pollution Prevention and
Toxics
William H. Sanders, III, Director
U.S. Department of Housing and Urban
Development
Andrew M. Cuomo, Secretary
Partnership for Advancing Technology
in Housing
Elizabeth J. Burdock, Director
\
U.S. Department of Commerce
William M. Daley, Secretary
Technology Administration
Dr. Cheryl L. Shavers, Under Secretary of
Commerce for Technology
National Institute of Standards and
Technology
Raymond G. Kammer, Director
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Abstract
The BEES (Building for Environmental and Economic Sustainability) version 2.0 software
implements a rational, systematic technique for selecting environmentally and economically
balanced building products. The technique is based on consensus standards and designed to be
practical, flexible, and transparent. The Windows-based decision support software, aimed at
designers, builders, and product manufacturers, includes actual environmental and economic
performance data for 65 building products across a range of functional applications. BEES
measures the environmental performance of building products using the environmental life-cycle
assessment approach specified in ISO 14040 standards. All stages in the life of a product are
analyzed: raw material acquisition, manufacture, transportation, installation, use, and waste
management. Economic performance is measured using the American Society for Testing and
Materials (ASTM) standard life-cycle cost method (E 917), which covers the costs of initial
investment, replacement, operation, maintenance and repair, and disposal. Environmental and
economic performance are combined into an overall performance measure using the ASTM
standard for Multiartribute Decision Analysis (E 1765). For the entire BEES analysis, building
products are defined and classified based on the ASTM standard classification for building
elements known as UNIFORMAT II (E 1557).
Key words: Building products, economic performance, environmental performance, green
buildings, life cycle assessment, life-cycle costing, multiattribute decision analysis, sustainable
development
Disclaimer
i J < JV ' ^ <. *•
The United ^ States Department of Commerce and NIjST do iwk endorse any particular'brand,
pro'duet, or service, 'The'enclosed information is provided for comparing,generic, U.S. .industry-
average product classes only and no- representations are made as to the quality or fitness of any
specific manufacturer's product Users shall not in any way say or imply that the information
obtained fiprh BEES is an endorsemenVof any particular product, service, or brand.
The BEES tool bears no warranty, neither express nor implied NIST does not assume legal liability
nor,responsibility for a User's utilization of BEES. NO WARRANTIES AS TO ANY MATTER
WHATSOEVER, ARE* - MADE BY J NEST, * INCLUDING NO .' .WARRANTY ' OF
MERCHANTABILITY OR FITNESS FOR A ^ARTICULAR PURPOSE.
in
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Acknowledgments
The BEES tool could not have been completed without the help of others. Thanks are due the
NlST Building and Fire Research Laboratory (BFRL) for its support of this work from its
inception. The ll.S. Environmental Protection Agency (EPA), Pollution Prevention Division also
deserves thanks for its continued support. Deserving special thanks is the BEES environmental
data contracting team of Environmental Strategies and Solutions and Ecobalance, Inc., for its
superb data development, documentation, and technical support. The author is grateful to the
EPA Framework for Responsible Environmental Decisionmaking team, led by Mary Ann Curran
of the EPA Sustainable Technology Division., for recommending methodology improvements that
have been incorporated into BEES 2.0. Thanks are also due Sarah Bretz and her colleagues from
Lawrence Berkeley National Laboratory for providing the Energy Star "Cool Roof data used to
analyze BEES roof covering alternatives. Also deserving special thanks are the 60 BEES 2.0 Beta
Testers for their tune spent reviewing the BEES 2.0 Beta version and their comments leading to
many improvements. The author is particularly grateful for the key cooperation and support
offered by a wide variety of industry associations and manufacturers with products represented in
BEES. Then: cooperation exceeded all expectations, and led to improvements in the underlying
BEES performance data. The comments of NIST BFRL colleagues Hunter Fanney, Harold Marshall,
Stephen Weber, and Mark Ehlen inspired many improvements. Special thanks are due Amy Boyles for
helping test, document, and review BEES 2.0. Thanks are also due Cathy Lintiiicum for her wonderful
secretarial support.
ware was eveloped at the National InstituteofStandards a3^
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Getting Started
System Requirements
BEES runs on Windows 95, Windows 98, Windows 2000, and Windows NT personal computers
with a 486 or higher microprocessor, 32 Mb or more of RAM, and at least 31 Mb of available
disk space. At least one printer must be installed
Installing BEES
From Download Site. Once you've completed the BEES registration form, click Submit, and then
click bees20.exe to download the self-extracting file. If prompted during the download, choose to
save the file to disk. Once downloaded, from Windows Explorer double click on the file to begin
the self-extraction process. Choose to unzip the file to a new folder. Once unzipped, from
Windows Explorer double click on the file SETUP.EXE in your new folder to begin the self-
explanatory BEES 2.0 installation process. During installation, you will need to choose a
directory to install BEES 2.0; you must choose a directory different from the one that contains the
setup file (SETUP.EXE). Once installation is complete, you are ready to run BEES 2.0 from
your program group BEES.
From CD-ROM. Install BEES by inserting the compact disc into your CD-ROM drive and
running the BEES setup program, SETUP.EXE. Follow on-screen installation instructions. Once
installation is complete, you are ready to run BEES 2.0 from your program group BEES.
Running BEES
First time BEES users may find it useful to read the BEES Tutorial, found in section 4 of this
report. The BEES Tutorial is a printed version of the BEES on-line help system, with step-by-step
instructions for running the software. The tutorial also includes illustrations of the screen displays.
Alternatively, first-time users may choose to double-click on the help icon installed in the BEES
program group at installation for an electronic version of the help system.
While running the BEES software, context-sensitive help is often available from the BEES Main
Menu. Context-sensitive help is also available through Help buttons on many of the BEES
windows.
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Contents
Abstract iii
i •
Acknowledgments iv
Getting Started v
Contents vi
i
List of Tables .. viii
List of Figures x
1. Background and Introduction 1
2. The BEES Model .3
2.1 Environmental Performance 4
2.1.1 Goal and Scope Definition 4
2.1.2 Inventory Analysis ...6
2.1.3 Impact Assessment 8
2.1,4 Interpretation 27
2.2 Economic Performance 32
2.3 Overall Performance 34
2.4 Limitations 34
i i
3. BEES Product Data 39
3.1 Portland Cement Concrete Slabs, Walls, Beams, and Columns (BEES Codes A1030,
A2b20,B1011,B1012) 39
3.2 Rppf and Wall Sheathing Alternatives (B1020, B2015) 45
3.2.1 Oriented Strand Board Sheathing (B1020A, B2015A) 45
3.2.2 Plywood Sheathing (B1020B, B2015B) 48
3.3 Exterior Wall Finish Alternatives (B2011) 51
3.3.1 Brick and Mortar (B2011 A) ....51
3.3.2 Stucco (B201 IB) 53
3.3.3 Aluminum Siding (B2011C) 56
3.3.4 Cedar Siding (B201 ID) . 57
3.3.5 Vinyl Siding (B201 IE) 58
3.4 Wall and Ceiling Insulation Alternatives (B2012, B3012) 60
3.4.1 Blown Cellulose Insulation (B2012A, B3012A)..... 60
3.4,2 Fiberglass Bart Insulation (B2012B, B2012C, B2012E, B3012B) 63
3.4.3 Blown Fiberglass Insulation (B3012D) 66
3.4.4 Blown Mineral Wool Insulation (B2012D, B3012C) 68
3.5 Framing Alternatives (B2013) 71
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3.5.1 Steel Framing (B2013A) ; 71
3.5.2 Wood Framing (B2013B) 73
3.6 Roof Covering Alternatives (B3011) 75
3.6.1 Asphalt Shingles (B3011 A) 75
3.6.2 Clay Tile (B301 IB) 78
3.6.3 Fiber Cement Shingles (B3011C) 81
3.7 Interior Finishes (C3012) 83
3.7.1 Paints - General Information ; 83
3.7.2 Virgin Latex Interior Paint (C3012A) 84
3.7.3 Recycled Latex Interior Paint (C3012B) 86
3.8 Floor Covering Alternatives (C3020) 87
3.8.1 Ceramic Tile with Recycled Windshield Glass (C3020A) 87
3.8.2 Linoleum Flooring (C30202) 89
3.8.3 Vinyl Composition Tile (C3020C) 92
3.8.4 Composite Marble Tile (C3020D) 94
3.8.5 Terrazzo (C3020E) 96
3.8.6 Carpeting - General Information 98
3.8.7 Wool Carpet (C3020G,C3020J,C3020M,C3020P) 100
3.8.8 Nylon Carpet (C3020F,C3020I,C3020L,C3020O) 104
3.8.9 Recycled Polyester Carpet (C3020H,C3020K,C3020N,C3020Q) 106
3.9 Parking Lot and Driveway Paving Alternatives (G2022,G2031) 108
3.9.1 Concrete Paving (G2022A, G2022B, G2022C, G2031A, G2031B, G2031C) .. 108
3.9.2 Asphalt Parking Lot Paving with GSB88 Asphalt Emulsion Maintenance
(G2022D) 110
3.9.3 Asphalt Parking Lot Paving with Asphalt Cement Maintenance (G2022E) 112
3.9.4 Asphalt Driveway Paving with Sealer Maintenance (G2031D) 114
4. BEES Tutorial 117
4.1 Setting Parameters 117
4.2 Defining Alternatives '. 120
4.3 Viewing Results ; 122
4.4 Browsing Environmental and Economic Performance Data 123
5. Future Directions 133
Appendix A. BEES Computational Algorithms , 134
A.1 Environmental Performance 134
A.2 Economic Performance , 135
A.3 Overall Performance 135
References.
136
Vll
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List of Tables
Table 2.1 BEES Global Warming Potential Equivalency Factors 12
Table 2.2 BEES Acidification Potential Equivalency Factors 13
Table 2.3 BEES Eutrophication Potential Equivalency Factors 14
Table 2.4 BEES Natural Resource Depletion Equivalency Factors 16
Table 2.5 Densities of BEES Building Products 17
Table 2.6 Volatile Organic Compound Emissions for BEES Floor Coverings 18
Table 2.7 BEES Indoor Air Performance Scores for Floor Covering Products 19
Table 2.8 BEES Ozone Depletion Potential Equivalency Factors 22
Table 2.9 Sampling of BEES Maximum Incremental Reactivity Equivalency Factors 24
Table 2.10 Sampling of Ecological Toxicity Potential Equivalency Factors 26
Table 2.11 Sampling of Human Toxicity Potential Equivalency Factors 27
Table 2.12 Pairwise Comparison Values for Deriving Impact Category Importance Weights 29
Table 2.13 Relative Importance Weights based on Science Advisory Board Study 29
Table 2.14 U.S. Rankings for Current and Future Consequences by Impact Category 30
Table 2.15 Relative Importance Weights based on Harvard University study 31
Table 3.1 Concrete Constituent Quantities by Compressive Strength of Concrete 42
Table 3.2 Energy Requirements for Portland Cement Manufacturing 43
Table 3.3 BEES Life-Cycle Cost Data Specifications and Codes for Concrete Products 44
Table 3.4 Oriented Strand Board Sheathing Constituents 46
Table 3.5 Oriented Strand Board Manufacturing Emissions 47
Table 3.6 Plywood Constituents 49
Table 3.7 Plywood Manufacturing Emissions 50
Table 3.8 Energy Requirements for Brick Manufacturing 52
Table 3.9 Masonry Cement Constituents 53
Table 3.10 Stucco Constituents 54
Table 3.11 Energy Requirements for Masonry Cement Manufacturing 55
Table 3.12 Density of Stucco by Type..... 55
Table 3.13 Aluminum Siding Constituents 56
Table 3.14 Energy Requirements for Cedar Siding Manufacture 58
Table 3.15 Hogfuel Emissions 58
Table 3-16 Vinyl Siding Constituents 60
Table 3.17 Blown Cellulose Mass by Application 61
Table 3.18 Blown Cellulose Insulation Constituents 61
Table 3.19 Fiberglass Batt Mass by Application 64
Table 3.20 Fiberglass Batt Constituents 65
Table 3.21 Energy Requirements for Fiberglass Batt Insulation Manufacturing 65
Table 3.22 Blown Fiberglass Mass 67
Table 3.23 Blown Fiberglass Constituents 67
Table 3.24 Energy Requirements for Fiberglass Insulation Manufacturing 68
Table 3.25 Blown Mineral Wool Constituents 69
Table 3.26 Energy Requirements for Mineral Wool Insulation Manufacturing 70
Table 3.27 Energy Requirements for Lumber Manufacture 74
Vlll
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Table 3.28 Hogfuel Emissions 74
Table 3.29 Asphalt Shingle Constituents 76
Table 3.30 Seven Kg (15 Ib) Roofing Felt Constituents 76
Table 3.31 Fourteen Kg (30 Ib) Roofing Felt Constituents 78
Table 3.32 Fiber Cement Shingle Constituents 81
Table 3.33 Characteristics of BEES Paints and Primer '... 84
Table 3.34 Virgin Latex Paint and Primer Constituents 85
Table 3.35 Market Shares of Resins 85
Table 3.36 Components of Paint Resins 85
Table 3.37 Ceramic Tile with Recycled Glass Constituents 87
Table 3.38 Energy Requirements for Ceramic Tile with Recycled Glass Manufacturing 88
Table 3.39 Linoleum Constituents 89
Table 3.40 Energy Requirements for Cork Flour Production 91
Table 3.41 Energy Requirements for Linoleum Manufacturing 91
Table 3.42 Linoleum Raw Materials Transportation 91
Table 3.43 Vinyl Composition Tile Constituents < 93
Table 3.44 Energy Requirements for Vinyl Composition Tile Manufacturing 93
Table 3.45 Composite Marble Tile Constituents • 94
Table 3.46 Energy Requirements for Composite Marble Tile Manufacturing 95
Table 3.47 Terrazzo Constituents 96
Table 3.48 Energy Requirements for Carpet Manufacturing 100
Table 3.49 Carpet Installation Parameters 100
Table 3.50 Wool Carpet Constituents i 101
Table 3.51 Raw Wool Material Flows , 102
Table 3.52 Raw Wool Constituents 102
Table 3.53 Wool Yarn Production Requirements , 103
Table 3.54 Wool Transportation , , 103
Table 3.55 Nylon Carpet Constituents 104
Table 3.56 Nylon Yarn Production Requirements 105
Table 3.57 Recycled Polyester Carpet Constituents 106
Table 3.58 Recycled PET Yarn Production Requirements 107
Table 3.59 Raw Materials for Asphalt Base Layer '. Ill
Table 3.60 Energy Requirements for Asphalt Paving with GSB88 Emulsion Maintenance 1123
Table 3.61 Raw Materials for Asphalt Cement Maintenance 113
Table 3.62 Energy Requirements for Asphalt Cement Maintenance 114
Table 3.63 Raw Materials for Driveway Sealer 115
Table 3.64 Energy Requirements for Asphalt Sealer Maintenance 116
Table 4.1 BEES Products Keyed to Environmental and Economic Performance Data Codes ... 131
IX
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List of Figures
Figure 2.1 Decision Criteria for Setting Product System Boundaries 5
Figure 2.2 BEES Inventory Data Categories.. 7
Figure 2.3 BEES Study Periods For Measuring Building Product Environmental And Economic
Performance 33
Figure 2.4 Deriving the BEES Overall Performance Score 36
Figure 3.1 Portland Cement Concrete Without Fly Ash Flow Chart 41
Figure 3.2 Portland Cement Concrete With Fly Ash or Slag Flow Chart .42
Figure 3.3 Oriented Strand Board Flow Chart 46
Figure 3.4 Plywood Sheathing Flow Chart 49
Figure 3.5 Brick and Mortar Flow Chart 51
Figure 3.6 Stucco (Type C) Flow Chart 54
Figure 3.7 Stucco (Type MS) Flow Chart 54
Figure 3.8 Aluminum Siding Flow Chart , 56
Figure 3.9 Cedar Siding Flow Chart 57
Figure 3.10 Vinyl Siding Flow Chart 59
Figure 3.11 Blown Cellulose Insulation Flow Chart 61
Figure 3.12 Fiberglass Bart Insulation Flow Chart 64
Figure 3.13 Blown Fiberglass Insulation Flow Chart 67
Figure 3.14 Blown Mineral Wool Insulation Flow Chart 69
Figure 3.15 Steel Framing Flow Chart 72
Figure 3.16 Wood Framing Flow Chart 74
Figure 3.17 Asphalt Shingles Flow Chart 76
Figure 3.18 Clay Tile Flow Chart 79
Figure 3.19 Fiber Cement Shingles Flow Chart 81
Figure 3.20 Virgin Latex Interior Paint Flow Chart 84
Figure 3.21 Recycled Latex Interior Paint Flow Chart 86
Figure 3.22 Ceramic Tile with Recycled Glass Flow Chart 88
Figure 3.23 Linoleum Flow Chart 90
Figure 3.24 Vinyl Composition Tile Flow Chart 93
Figure 3.25 Composite Marble Tile Flow Chart 95
Figure 3.26 Epoxy Terrazzo Flow Chart 97
Figure 3.27 Wool Carpet Flow Chart 101
Figure 3.28 Wool Fiber Production 102
Figure 3.29 Nylon Carpet Flow Chart '...'. 105
Figure 3.30 Recycled Polyester Carpet Flow Chart 107
Figure 3.31 Handling and Reclamation of PET 107
Figure 3.32 Concrete Paving Flow Chart 109
Figure 3.33 Asphalt with GSB88 Emulsion Maintenance Flow Chart Ill
Figure 3.34 Asphalt with Asphalt Cement Maintenance Flow Chart 113
Figure 3.35 Asphalt with Sealer Maintenance Flow Chart 115
Figure 4.1 Setting Analysis Parameters 118
Figure 4.2 Viewing Impact Category Weights 119
Figure 4.3 Entering User-Defined Weights 119
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Figure 4.4 Selecting Building Element for BEES Analysis ! 120
Figure 4.5 Selecting Building Product Alternatives • 121
Figure 4.6 Setting Transportation Parameters 122
Figure 4.8 Viewing BEES Overall Performance Results 125
Figure 4.9 Viewing BEES Environmental Performance Results .' 125
Figure 4.10 Viewing BEES Economic Performance Results 126
Figure 4.11 Viewing BEES Summary Table 126
Figure 4.12 Viewing BEES Environmental Impact Category Performance Results by Life-Cycle
Stage 127
Figure 4.13 Viewing BEES Environmental Impact Category Performance Results Contributing by
Flow 128
Figure 4.14 Viewing BEES Embodied Energy Results 129
Figure 4.15 A Sampling of BEES "All Tables In One" Display.; 130
XI
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1. Background and Introduction
Buildings significantly alter the environment. According to Worldwatch Institute,1 building
construction consumes 40 % of the raw stone, gravel, and sand used globally each year,
and 25 % of the virgin wood. Buildings also account for 40 % of the energy and 16 % of
the water used annually worldwide. In the United States, about as much construction and
demolition waste is produced as municipal garbage. Unhealthy indoor air is found in 30 %
of new and renovated buildings worldwide.
Negative environmental impacts arise from building construction and renovation. For
example, raw materials extraction can lead to resource depletion and biological diversity
losses. Building product manufacture and transport consumes energy, generating
emissions linked to global warming, acid rain, and smog. Landfill problems may arise from
waste generation. Poor indoor air quality may lower worker productivity and adversely
affect human health.
Selecting environmentally preferable building products is one way to reduce these negative
environmental impacts. However, while 93 % of U.S. consumers worry about their
home's environmental impact, only 18 % are willing to pay more to reduce the impact,
according to a survey of 3,600 consumers in 9 U.S. metropolitan areas.2 Thus,
environmental performance must be balanced against economic performance. Even the
most environmentally conscious building product manufacturer or designer will ultimately
weigh environmental benefits against economic costs. To satisfy their customers,
manufacturers and designers need to develop and select building products with an
attractive balance of environmental and economic performance.
Identifying environmentally and economically balanced building products is no easy task.
Today, the green building decisionmaking process is based on little structure and even less
credible, scientific data. There is a great deal of interesting green building information
available, so that in many respects we know what to say about green buildings. However,
we still do not know how to synthesize the available information so that we know what to
do in a way that is transparent, defensible, and environmentally sound.
In this spirit, the U.S. National Institute of Standards and Technology (NIST) Green
Buildings Program began the Building for Environmental and Economic Sustainability
(BEES) project in 1994. The purpose of BEES is to develop and implement a systematic
methodology for selecting building products that achieve the most appropriate balance
1 D.M. Roodman and N. Lenssen, A Building Revolution: How Ecology and Health Concerns are
Transforming Construction, Worldwatch Paper 124, Worldwatch Institute, Washington, DC, March 1995.
2 1995 Home Shoppers survey cited in Minneapolis Star Tribune, 11/16/96, p H4 (article by Jim
Buchta). According to another survey, Japanese consumers are willing to pay up to 25 % more for
environmentally friendly products (Maurice Strong, Chairman, Earth Council Institute, "Closing Day
Engineering and Construction for Sustainable Development in the 21st Century,
Washington, DC, February 4-8, 1996, p 54)
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between environmental and economic performance based on the decision maker's values.
The methodology is based on consensus standards and is designed to be practical, flexible,
and transparent. The BEES model is implemented in publicly available decision-support
software, complete with actual environmental and economic performance data for a
number of building products. The intended result is a cost-effective reduction in building-
related contributions to environmental problems.
i
In 1997, the U.S. Environmental Protection Agency's (EPA) Environmentally Preferable
Purchasing (EPP) Program also began supporting the development of BEES. The EPP
program is charged with carrying out Executive Order 13101, Greening the Government
Through Waste Prevention, Recycling, and Federal Acquisition, which directs Executive
agencies to reduce the environmental burdens associated with the $200 billion in products
and services they purchase each year, including building products. Over the next several
years, BEES will be further developed as a tool to assist the Federal procurement
community in carrying out the mandate of Executive Order 13101.
In 1999, the U.S. Department of Housing and Urban Development's (HUD) Partnership
for Advancing Technology in Housing (PATH) Program began supporting the
development of BEES data for residential building products. This year, PATH is
supporting an effort to explore the technical and economic feasibility together with the
most suitable framework for a residential version of BEES. This work is based on input
from homebuUders, residential designers, and product suppliers. The purpose is to
provide a useful tool for the residential sector.
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2. The BEES Model
The BEES methodology takes a multidimensional, life-cycle approach. That is, it
considers multiple environmental and economic impacts over the entire life of the building
product. Considering multiple impacts and life-cycle stages is necessary because product
selection decisions based on single impacts or stages could obscure others that might
cause equal or greater damage. In other words, a multidimensional, life-cycle approach is
necessary for a comprehensive, balanced analysis.
It is relatively straightforward to select products based on minimum life-cycle economic
impacts because building products are bought and sold in the marketplace. But how do we
include life-cycle environmental impacts in our purchase decisions? Environmental impacts
such as global warming, water pollution, and resource depletion are for the most part
economic externalities. That is, their costs are not reflected in the market prices of the
products that generated the impacts. Moreover, even if there were a mandate today to
include environmental "costs" in market prices, it would be nearly impossible to do so due
to difficulties in assessing these impacts in economic terms. How do you put a price on
clean air and clean water? What is the value of human life? Economists have debated these
questions for decades, and consensus does not appear likely.
While environmental performance cannot be measured on a monetary scale, it can be
quantified using the evolving, multi-disciplinary approach known as environmental life-
cycle assessment (LCA). The BEES methodology measures environmental performance
using an LCA approach, following guidance in the International Standards Organization
14040 series of standards for LCA.3 Economic performance is separately measured using
the American Society for Testing and Materials (ASTM) standard life-cycle cost (LCC)
approach. These two performance measures are then synthesized into an overall
performance measure using the ASTM standard for Multiattribute Decision Analysis.4 For
the entire BEES analysis, building products are defined and classified based on
UNIFORMATII, the ASTM standard classification for building elements.5
3 International Standards Organization, Environmental Management—Life-Cycle Assessment-
Principles and Framework, International Standard 14040, 1997; ISO Environmental Management-Life-
Cycle Assessment—Goal and Scope Definition and Inventory Anslysis, International Standard 14041,
1998; and ISO Environmental Management—Life-Cycle Assessment—Life Cycle Impact Assessment,
International Standard 14042, 2000.
4 American Society for Testing and Materials, Standard Practice for Applying the Analytic Hierarchy
Process to Multiattribute Decision Analysis of Investments Related to Buildings and Building Systems,
ASTM Designation E 1765-98, West Conshohocken, PA, 1998.
5 American Society for Testing and Materials, Standard Classification for Building Elements and
Related Sitework-UNIFORMATII, ASTM Designation E 1557-97, West Conshohocken, PA, September
1997.
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2.1 Environmental Performance
Environmental life-cycle assessment is a "cradle-to-grave," systems approach for
measuring environmental performance. The approach is based on the belief that all stages
in the life of a product generate environmental impacts and must therefore be analyzed,
including raw materials acquisition, product manufacture, transportation, installation,
operation and maintenance, and ultimately recycling and waste management. An analysis
that excludes any of these stages is limited because it ignores the full range of upstream
and downstream impacts of stage-specific processes.
The strength of environmental life-cycle assessment is its comprehensive, multi-
dimensional scope. Many green building claims and strategies are now based on a single
life-cycle stage or a single environmental impact. A product is claimed to be green simply
because it has recycled content, or claimed not to be green because it emits volatile
organic compounds (VOCs) during its installation and use. These single-attribute claims
may be misleading because they ignore the possibility that other life-cycle stages, or other
environmental impacts, may yield offsetting impacts. For example, the recycled content
product may have a high embodied energy content, leading to resource depletion, global
warming, and acid rain impacts during the raw materials acquisition, manufacturing, and
transportation life-cycle stages. LCA thus broadens the environmental discussion by
accounting for shifts of environmental problems from one life-cycle stage to another, or
one environmental medium (land, air, water) to another. The benefit of the LCA approach
is in implementing a trade-off analysis to achieve a genuine reduction in overall
environmental impact, rather than a simple shift of impact.
]
The general LCA methodology involves four steps.6 The goal and scope definition step
spells out the purpose of the study and its breadth and depth. The inventory analysis step
identifies and quantifies the environmental inputs and outputs associated 'with a product
over its entire life cycle. Environmental inputs include water, energy, land, and other
resources; outputs include releases to air, land, and water. However, it is not these inputs
and outputs, or inventory flows, that are of primary interest. We are more interested in
their consequences, or impacts on the environment. Thus, the next LCA step, impact
assessment, characterizes these inventory flows in relation to a set of environmental
impacts. For example, the impact assessment step might relate carbon dioxide emissions, a
flow, to global warming, an impact. Finally, the interpretation step combines the
environmental impacts in accordance with the goals of the LCA study.
2.1.1 Goal and Scope Definition
The goal of the BEES LCA is to generate relative environmental performance scores for
building product alternatives based on U.S. average data. These will
be combined with
6 International Standards Organization, Environmental Management—Life-Cycle Assessment-
Principles and Framework, Draft International Standard 14040, 1996.
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relative, U.S. average economic scores to help the building community select
environmentally and economically balanced building products.
The scoping phase of any LCA involves defining the boundaries of the product system
under study. The manufacture of any product involves a number of unit processes (e.g.,
ethylene production for input to the manufacture of the styrene-butadiene bonding agent
for stucco walls). Each unit process involves many inventory flows, some of which
themselves involve other, subsidiary unit processes. The first product system boundary
determines which unit processes are included in the LCA. hi the BEES system, the
boundary-setting rule consists of a set of three decision criteria. For each candidate unit
process, mass and energy contributions to the product system are the primary decision
criteria. In some cases, cost contribution is used as a third criterion.7 Together, these
criteria provide a robust screening process, as illustrated in Figure 2.1, showing how five
ancillary materials (e.g., limestone used in portland cement manufacturing) are selected
from a list of nine candidate materials for inclusion in the LCA. A material must have a
large contribution to at least one decision criterion to be selected. The weight criterion
selects materials A, B, and C; the energy criterion adds material E; and cost flags material
I. As a result, the unit processes for producing ancillary materials A, B, C, E, and I are
included in the system boundaries.
Ancillary
Material
Weight
Energy
Cost
(as a flag
when
necessary)
Included in
system
boundaries
Yes
negligible contribution
small contribution
large contribution
Figure 2.1 Decision Criteria for Setting Product System Boundaries
The second product system boundary determines which inventory flows are tracked for in-
bounds unit processes. Quantification of all inventory, flows is not practical for the
following reasons:
7 While a large cost contribution does not directly indicate a significant environmental impact, it may
indicate scarce natural resources or numerous subsidiary unit processes potentially involving high energy
consumption.
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• An ever-expanding number of inventory flows can be tracked. For instance, inchiding
the U.S. Environmental Protection Agency's Toxic Release Inventory (TRI) data
would result in tracking approximately 200 inventory flows arising from polypropylene
production alone. Similarly, including radionucleide emissions generated from
elpctricity production would result in tracking more than 150 flows. Managing such
large inventory flow lists adds to the complexity, and thus the cost, of carrying out and
interpreting the LCA.
• Attention should be given in the inventory analysis step to collecting data that will be
useful in the next LCA step, impact assessment. By restricting the inventory data
collection to the flows actually needed in the subsequent impact assessment, a more
focused, higher quality LCA can be carried out.
Therefore, in the BEES model, a focused, cost-effective set of inventory flows is tracked,
reflecting flows that will actually be needed in the subsequent impact assessment step.
Defining the unit of comparison is another important task in the goal and scoping phase of
LCA. The basis for all units of comparison is the functional unit, defined so that the
products compared are true substitutes for one another. In the BEES model, the functional
unit for most building products is 0.09 m2 (1 ft2) of product service for 50 years.8'9
Therefore, for example, the functional unit for the BEES roof covering alternatives is
covering 0.09 m2 (1 ft2) of roof surface for 50 years. The functional unit provides the
critical reference point to which all inventory flows are scaled.
Scoping also involves setting data requirements. Data requirements for the BEES study
include:
i , i i
• Geographic coverage: The data are U.S. average data.
• Time period covered: The data are a combination of data collected specifically for
BEES within the last 6 years, and data from the well-known Ecobalance LCA
database created in 1990.10 Most of the Ecobalance data are updated annually. No
data older than 1990 are used.
• Technology covered: When possible, the most representative technology is studied.
Where data for the most representative technology are not available, an aggregated
result is used based on the U.S. average technology for that industry.
2.1.2 Inventory Analysis
8 All product alternatives are assumed to meet minimum technical performance requirements (e.g.,
acoustic and fire performance).
9 The functional unit for concrete products except concrete paving is 0.76 cubic meters (1 cubic yard)
of product service for 50 years.
10 Ecobalance, Inc., DEAM™ 3.0: Data for Environmental Analysis and Management, Bethesda, MD,
1999.
...I ::
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Inventory analysis entails quantifying the inventory flows for a product system. Inventory
flows include inputs of water, energy, and raw materials, and releases to air, land, and
water. Data categories are used to group inventory flows in LCAs. For example, in the
BEES model, flows such as aldehydes, ammonia, and sulfur oxides are grouped under the
air emissions data category. Figure 2.2 shows the categories under which data are grouped
in the BEES system. Refer to the BEES environmental performance data files, accessible
through the BEES software, for a detailed listing of approximately 400 inventory flow
items included in BEES.
Raw Materials
-Energy-
-Water-
Unit
Process
I
Intermediate Material
or Final Product
t
—Air Emissions—
-Water Effluents-
-Releases to Land -
—Other Releases—
Figure 2.2 BEES Inventory Data Categories
A number of approaches may be used to collect inventory data for LCAs. These range
from:11
• Unit process- and facility-specific: collect data from a particular process within a given
facility that are not combined in any way
• Composite: collect data from the same process combined across locations
• Aggregated: collect data combining more than one process
• Industry-average: collect data derived from a representative sample of locations
believed to statistically describe the typical process across technologies
• Generic: collect data whose representatives may be unknown but which are
qualitatively descriptive of a process
Since the goal of the BEES LCA is to generate U.S. average results, data are primarily
collected using the industry-average approach. Data collection is done under contract with
11 U.S. Environmental Protection Agency, Office of Research and Development, Life Cycle
Assessment: Inventory Guidelines and Principles, EPA/600/R-92/245, February 1993.
-------
Environmental Strategies and Solutions (ESS) and Ecobalance, Inc., using the Ecobalance
LCA database covering more than 6,000 industrial processes gathered from actual site and
literature searches from more than 15 countries. Where necessary, the data are adjusted to
be representative of U.S. operations and conditions. Approximately 90 % of the data
come directly from industry sources, with about 10 % coming from generic literature and
published reports. The generic data include inventory flows for electricity production
from the average United States grid, and for selected raw material mining operations (e.g.,
limestone, sand, and clay mining operations). In addition, ESS and Ecobalance gathered
additional LCA data to fill data gaps for the BEES products. Assumptions regarding the
unit processes for each building product are verified through experts in the appropriate
industry to assure the data are correctly incorporated in BEES.
2.1.3 Impact Assessment
'!„ •: '"' '" • ,: •' i1 ''!'
The impact assessment step of LCA quantifies the potential contribution of a product's
inventory flows to a range of environmental impacts. There are several well-known LCA
impact assessment approaches.
Direct Use of Inventories. In the most straightforward approach to LCA, the impact
assessment step is skipped, and the life cycle inventory results are used as-is in the final
interpretation step to help identify opportunities for pollution prevention or increases in
material and energy efficiency for processes within the life cycle. However, this approach
in effect gives the same weight to all inventory flows (e.g., to the reduction of carbon
dioxide emissions and to the reduction of lead emissions). For most impacts, equal
weighting of flows is unrealistic.
Critical Volumes (Switzerland). The "weighted loads" approach, better known as the
Swiss critical volume approach, was the first method proposed for aggregating inventory
flow data.12 The critical volume for a substance is a function of its load and its legal limit.
Its load is the total quantity of the flow per unit of the product. Critical volumes can be
defined for air and water, and in principle also for soil and groundwater, providing there
are legal limit values available.
This approach has the advantage that long lists of inventory flows, especially for air and
water, can be aggregated by summing the critical volumes for the individual flows within
the medium being considered—air, water, or soil. However, the critical volume approach is
rarely used today due to the following disadvantages of using legal limit values:
12 K. Habersatter, Ecobalance of Packaging Materials - State of 1990, Swiss Federal Office of
Environment, Forests, and Landscape, Bern, Switzerland, February 1991, and Bundesamt fur
Umweltschutz, Oekobilanzen von Packstoffen, Schriftenreihe Umweltschutz 24, Bern, Switzerland, 1984.
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• Legal limit values are available only for certain chemicals and pollutants. Long-term
global effects such as global warming are excluded since there are no legal limits for
the chemicals involved.
• Legal limit values often differ from country to country, and their basis is far from being
purely scientific. Socioeconomic factors, technical limitations (for example, analytical
detection limits), and the feasibility of supervision and control are also taken into
account when arriving at legal limits.
Ecological Scarcity (Switzerland). A more general approach has been developed by the
Swiss Federal Office of Environment, Forests, and Landscape.13 With this approach, "Eco-
Points" are calculated for a product, using the "Eco-Factor" determined for each inventory
flow. Eco-Factors are based on current annual flows relative to target maximum annual
flows for the geographic area considered. The Eco-Points for all inventory flows are
added together to give one single, final score.
The concept used in this approach is appealing but has the following difficulties:
• It is valid only in a specific geographical area.
• Estimating annual and target flows can be a difficult and time-consuming exercise.
• The scientific calculation of environmental impacts is combined with political and
subjective judgment, or valuation. The preferred approach is to separate the science
from the valuation.
Environmental Priorities System (Sweden). The Environmental Priority Strategies in
Product Design System, the EPS System, was developed by the Swedish Environmental
Research Institute. It takes an economic approach to assessing environmental impacts.
The basis for the evaluation is the Environmental Load Unit, which corresponds to the
willingness to pay 1 European Currency Unit. The final result of the EPS system is a single
number summarizing all environmental impacts, based on:
• Society's judgment of the importance of each environmental impact.
• The intensity and frequency of the impact.
• Location and timing of the impact.
• The contribution of each flow to the impact in question.
• The cost of decreasing each inventory flow by one weight unit.
13 Ahbe S. Braunschweig A., and R. Muller-Wenk, Methodikfur Oekobilanzen aufder bases
Okologischer Optimierung, Schriftenreihn Umwelt 133, Swiss Federal Office of Environment, Forests,
and Landscape, October 1990.
14 Steen B., and S-O Ryding, The EPSEnviro-Accounting Method, TVL Report, Swedish
Environmental Research Institute, Goteborg, Sweden, 1992.
-------
The EPS system combines indices of ecological, sociological, and economic effects to give
a total effect index for each flow. The total effect index is multiplied by the amount of the
flow to give the "environmental load unit." Although this methodology is popular in
Sweden, its use is criticized due to its lack of transparency and the quantity and quality of
the model's underlying assumptions.
Classification/Characterization. The classification/characterization approach to impact
assessment was developed within the Society for Environmental Toxicology and
Chemistry (SETAC). It involves a two-step process:15'16'17
• Classification of inventory flows that contribute to specific environmental impacts. For
' example, greenhouse gases such as carbon dioxide, methane, and nitrous oxide are
classified as contributing to global warming.
• Characterization of the potential contribution of each classified inventory flow to the
corresponding environmental impact. This results in a set of indices, one for each
impact, that is obtained by weighting each classified inventory flow by its relative
contribution to the impact. For instance, the Global Warming Potential index is
derived by expressing each contributing inventory flow in terms of its equivalent
amount of carbon dioxide.
The BEES model uses this classification/characterization approach because it enjoys some
general consensus among LCA practitioners and scientists.18 The following global and
regional impacts are assessed using the classification/characterization approach: Global
Warming Potential, Acidification Potential, Eutrophication Potential, and Natural
Resource Depletion. Indoor Air Quality and Solid Waste impacts are also included in
BEES, for a total of six impacts for most BEES products.
As part of its Framework for Responsible Environmental Decisionmaking project, EPA
confirmed the validity of the six impacts included in BEES 1.0. In addition, EPA
suggested that four additional impacts be pilot tested in BEES 2.0: Smog, Ecological
Toxicity, Human Toxicity, and Ozone Depletion.19 For a select group of products,
BEES 2.0 also assesses Smog and in some cases Ecological Toxicity, Human
Toxicity, and Ozone Depletion as well. These "expanded impact" products are
identified in table 4.1. Note that the data and science underlying measurement of
these four impacts are less certain than for the original six BEES impacts. The
classification/characterization method does not offer the same degree of relevance for all
environmental impacts. For global and regional effects (e.g., global warming and
15 SETAC-Europe, Life Cycle-Assessment, B. DeSmet, et al. (eds), 1992.
16 SETAC, 4 Conceptual Framework for Life Cycle Impact Assessment, J. Fava, et al. (eds), 1993.
17 SET AC, Guidelines for Life Cycle Assessment: A "Code of Practice," F. Consoli, et al. (eds), 1993.
18 SETAC, Life-Cycle Impact Assessment: The State-of-the-Art, J. Owens, et al. (eds), 1997.
" U.S. EPA, Framework for Responsible Environmental Decisionmaking (FRED): Using Life Cycle
Assessment to Evaluate Preferability of Products, by Science Applications International Corporation,
Research Triangle Institute, and EcoSense, Inc, Draft Report, 1999.
10
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acidification) the method may result in an accurate description of the potential impact. For
impacts dependent upon local conditions (e.g., smog, ecological toxicity, and human
toxicity) it may result in an oversimplification of the actual impacts because the indices are
not tailored to localities.
If the BEES user has important knowledge about other potential environmental impacts, it
should be brought into the interpretation of the BEES results. The ten BEES impacts are
discussed below.
Global Warming Potential. The Earth absorbs radiation from the Sun, mainly at the
surface. This energy is then redistributed by the atmosphere and ocean and re-radiated to
space at longer wavelengths. Some of the thermal radiation is absorbed by "greenhouse"
gases in the atmosphere, principally water vapor, but also1 carbon dioxide, methane, the
chlorofluorocarbons, and ozone. The absorbed energy is re-radiated in all directions,
downwards as well as upwards, such that the radiation that is eventually lost to space is
from higher, colder levels in the atmosphere. The result is that the surface loses less heat
to space than it would in the absence of ..the greenhouse gases and consequently stays
warmer than it would be otherwise. This phenomenon, which acts rather like a 'blanket'
around the Earth, is known as the greenhouse effect.
The greenhouse effect is a natural phenomenon. The environmental issue is the increase
in the greenhouse effect due to emissions generated by humankind. The resulting general
increase in temperature can alter atmospheric and oceanic temperatures, which can
potentially lead to alteration of circulation and weather patterns. A rise in sea level is also
predicted due to thermal expansion of the oceans and melting of polar ice sheets. Global
Warming Potentials, or GWPs, have been developed to measure the increase.
Several models have been developed to calculate GWPs. The Intergovernmental Panel on
Climate Change (IPCC) has compiled a list of "provisional best estimates" for GWPs,
based on the expert judgment of scientists worldwide.20 Because of its broad support,
this list has been used in the BEES model.
A single index, expressed in grams of carbon dioxide per functional unit of product, is
derived to measure the quantity of carbon dioxide with the same potential for global
warming:
global warming index = Ej Wj x GWPi5 where
20 International Panel on Climate Change (IPCC), IPCC Second Assessment—Climate Change 1995: A
Report of the Intergovernmental Panel on Climate Change, 1996.
11
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Wj = weight (in grams) of inventory flow i, and
GWPi = grams of carbon dioxide with the same heat trapping potential as one
gram of inventory flow i, as listed in Table 2.1.
Table 2.1 BEES Global Warming Potential Equivalency Factors
GWPn
Flow(i)
Carbon dioxide
Methane
Nitrous oxide
(COz-equivalents)
1
24
360
Acidification. Acidifying compounds may in a gaseous state either dissolve in water or
fix on solid particles. They reach ecosystems through dissolution in rain or wet
deposition. Acidification affects trees, soil, buildings, animals, and humans. The two
compounds principally involved in acidification are sulfur and nitrogen compounds. Their
principal human source is fossil fuel and biomass combustion. Other compounds released
by human sources, such as hydrogen chloride and ammonia, also contribute to
acidification.
An index for potential acid deposition onto the soil and in water can be developed by
analogy with the global warming potential, with hydrogen as the reference substance. The
result is a single index for potential acidification (in grams of hydrogen per functional unit
of product), representing the quantity of hydrogen emissions with the same potential
acidifying effect:
• ' : i
acidification index = Sj Wj * APj, where
Wj = weight (in grams) of inventory flow i, and
APj = grams of hydrogen with the same potential acidifying effect as one gram of
inventory flow i, as listed in Table 2.2.21
21 CML, Environmental Life Cycle Assessment of Products: Background, Leiden, The Netherlands,
October 1992.
12
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Table 2.2 BEES Acidification Potential Equivalency Factors
Flow (i)
Sulfur oxides
Nitrogen oxides
Ammonia
Hydrogen Fluoride
Hydrogen Chloride
(Hydrogen-
Equivalefits)
0.031
0.022
0.059
0.050
0.027
Eutrophication Potential. Eutrophication is the addition of mineral nutrients to the soil or
water. In both media, the addition of large quantities of mineral nutrients, such as nitrogen
and phosphorous, results in generally undesirable shifts in the number of species in
ecosystems and a reduction in ecological diversity. In water, it tends to increase algae
growth, which can lead to lack of oxygen and therefore death of species like fish.
An index for potential eutrophication can be developed by analogy with the global
warming potential, with phosphate ions as the reference substance. The result is a single
index for potential eutrophication (in grams of phosphate ions per functional unit of
product), representing the quantity of phosphate ions with the same potential nutrifying
effect:
eutrophication index = E; wf x EPj, where
Wj = weight (in grams) of inventory flow i, and
EP; = grams of phosphate ions with the same potential nutrifying effect as one
grams of inventory flow i, as listed in Table 2.3.22
Natural Resource Depletion. Natural resource depletion can be defined as the decreasing
availability of natural resources. The resources considered in this impact are fossil and
mineral resources. It is important to recognize that this impact addresses only the
depletion aspect of resource extraction, not the fact that the extraction itself may
generate impacts. Extraction impacts, such as methane emissions from coal mining, are
addressed in other impacts, such as global warming.
22 CML, 1992.
13
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Table 2.3 BEES Eutrophication Potential Equivalency Factors
Flow (i)
(phosphate-
equivalents)
Phosphates 1.00
Nitrogen Oxides 0.13
Ammonia 0.42
Nitrogenous Matter 0.42
Nitrates 0.10
Phosphorous 3.06
Chemical Oxygen Demand 0.02
Some experts believe resource depletion is fully accounted for in market prices. That is,
market price mechanisms are believed to take care of the scarcity issue, price being a
measure of the level of depletion of a resource and the value society places on that
depletion. However, price is influenced by many factors other than resource supply, such
as resource demand and non-perfect markets (e.g., monopolies and subsidies).
Furthermore, resource depletion is at the heart of the sustainability debate. Thus, in the
BEES model, resource depletion is explicitly accounted for hi the LCA impact
assessment.
To assess resource depletion, the amount of reserves of a resource,
needs to be determined. For mineral resources, the reserve base is defined
or resource base,
as follows:
The reserve base encompasses those parts of the resources that have a
reasonable potential for becoming economically available within planning
horizons beyond those that assume proven technology and current
economics. It includes those resources that are currently economic,
marginally economic, and subeconomic.23
Reserve base quantities used in the BEES model are listed in Table 2.4.
Once reserves are established, an equivalency factor can be derived for each resource that
will relate its inventory flow with the depletion of the resource. The equivalency factor
addresses how long a given resource will continue to be available at current extraction
levels, as well as the size of the reserve. Using equivalency factors, a single index is
produced for natural resource depletion:
23
U.S. Department of the Interior, Bureau of Mines, Mineral Commodity Summary, 1994.
14
i • !.• .[. t
.. t,Milli ill".
-------
Depletion Index =
1 *w =y production^
r reserve { * years { ' *? (reserve {)2
where:
reservej = reserves (in kg) for natural resource i (the larger the reserve, the smaller
the equivalency factor)
yearsi = years of remaining use for natural resource i (the longer available, the
smaller the equivalency factor)
production = annual production (in kg/year) for natural resource i
Wi = the weight (in kg) of the inventory flow for resource i
The BEES natural resource depletion equivalency factors are shown in the last column of
Table 2.4.
Solid Waste. Solid waste is an inventory outflow of the building products included in the
BEES system. The BEES inventory analysis tracks the weight of non-recyclable solid
waste resulting from the installation, replacement, and disposal of each building product
over the 50-year study period. Equivalency factors have not been developed to consider
the ultimate fate of the non-recyclable solid waste (e.g., landfill leachate, gas or incinerator
emissions, and ash). Thus, the Direct Use of Inventories Approach, described at the
beginning of this subsection, is used, with solid waste volume representing the solid waste
impact of the product. Solid waste volume (in m3, or ft3, of waste per functional unit of
product) is derived as follows:
solid waste volume = (S; w; ) / density,
where:
Wj = weight (in kg) of non-recyclable solid waste inventory flow i, and
density = density of the product (in kg/0.0283 m3, or kg/ ft3), as listed in Table 2.5.
Indoor Air Quality. Indoor air quality impacts are not included in traditional life-cycle
impact assessments. Most LCAs conducted to date have been applied to relatively short-
lived, non-building products (e.g., paper versus plastic bags), for which indoor air quality
impacts are not an important issue. However, the indoor air performance of building
products is of particular concern to the building community and should be explicitly
considered in any building product LCA.
Ideally, equivalency factors would be available for indoor air pollutants as they are for
global warming gases. However, there is little scientific consensus about the relative
contributions of pollutants to indoor air performance. In the absence of equivalency
15
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I
I
I
g
1
,L
-------
^
Density
kg/0. 0283m3 (Jb/ft3)
Product
All Concrete Products
All Asphalt Products
Roof and Wall Sheathing
- Oriented Strand Board
- Plywood
Exterior Wall Finishes
-Brick
- Stucco
- Cedar Siding
- Aluminum Siding
- PVC. Siding
Interior Wall Finishes
- Recycled Latex Paint
- Virgin Latex Paint
Batt Insulation
-R-ll Fiberglass
-R-13 Fiberglass
- R-15 Fiberglass
- R-30 Fiberglass
Blown Insulation
- R-13 Cellulose
- R-30 Cellulose
- R-12 Mineral Wool
- R-30 Mineral Wool
- R-30 Fiberglass
Roof Coverings
- Asphalt Shingles
- Clay Tile
- Fiber Cement Shingles
Framing
- Steel
-Wood
Floor Coverings
- Ceramic Tile
- Linoleum
- Vinyl Composition Tile
- Composite Marble Tile
- Terrazzo
- Tile Carpet
- Broadloom Carpet
66 (145)
66 (145)
18 (38)
13 (28)
60 (132)
55 (121)
17 (37)
76 (168)
39 (87)
36 (80)
36 (80)
0.23 (0.5)
0.36 (0.8)
0.68 (1.5)
0.23 (0.5)
0.73 (1.6)
0.73 (1.6)
0.98 (2.2)
0.98 (2.2)
0.35 (0.75)
89 (196)
60 (132)
44 (97)
224 (493)
13 (29)
61(134)
33 (73)
59 (130)
73 (161)
72 (159)
6.3 (14)
6.2 (14)
factors, a product's total volatile organic compound (VOC) emissions are often used as a
measure of its indoor air performance. Note that total VOCs equally weights the contributions of
the individual compounds that make up the measure. Further, reliance on VOC emissions alone
17
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may be misleading if other indoor air contaminants, such as particulates and aerosols, are also
present.
Indoor air quality should be considered for the following building elements currently covered in
BEES: floor coverings, interior wall finishes, wall and roof sheathing, and wall and ceiling
insulation. Other BEES building elements are primarily exterior or inert interior elements for
which indoor air quality is not an issue.
Floor Coverings. BEES currently includes 17 floor covering products. Data for two components
of their indoor air performance are considered—total VOC emissions from the products
themselves and indoor air performance for their installation adhesives.
Recognizing the inherent limitations in using total VOCs to assess indoor air quality performance,
and in the absence of more scientific data, estimates of total VOC emissions from the floor
covering products are used as a proxy for their indoor air performance. Ceramic tile, composite
marble tile, and terrazzo are inert and emit no VOCs.24 Total VOCs for all other BEES floor
coverings are shown in Table 2.6.
Table 2.6 Volatile Organic Compound Emissions for BEES Floor Coverings
Floor Covering
Linoleum
Vinyl Composition
Tilea>b
Carpet0
Total Volatile Organic
Compound Emissions
_JMg/m*/li at 24 h)
1.667
0.155
0.500
* Averages for three linoleum and two VCT emissions tests conducted in a test chamber designed in accordance with ASTM
D5116-90 at Air Quality Sciences Laboratory, Atlanta, Georgia, 1991-1992.
Note that vinyl composition tile has substantially lower polyvinylchloride (PVC) and plasticizer content than vinyl sheet
flooring and thus emits lower levels of VOCs. Some vinyl sheet flooring may emit higher levels of VOCs than linoleum.
c Carpet and Rug Institute (CRI) emissions standard for green labelling. Seventy-five percent of carpets tested meet these
standards.
The second component of the BEES indoor air assessment for floor coverings is indoor air
performance for their installation adhesives. Linoleum, vinyl composition tile, and carpets installed
with traditional synthetic adhesives are assumed to be installed using a styrene-butadiene adhesive,
and ceramic tile with recycled glass and composite marble tile using a styrene-butadiene cement
mortar. Carpets installed with a low-VOC styrene-butadiene adhesive are assumed to have 17 %
24 American Institute of Architects, Environmental Resource Guide, Ceramic Tile Material Report, p. 1, and
Terrazzo Material Report, p. 1, 1996.
18
Uk, Hull,1,1
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the emissions of an equivalent quantity of traditional styrene-butadiene adhesive.25 Assuming
indoor air impacts are proportional to the amount of styrene-butadiene used per functional unit
(as quantified in the BEES environmental performance data files), styrene-butadiene usage may be
used as a proxy for indoor air performance as follows:
• linoleum—0.00878 kg/m2 (0.00079 kg/ft2)
• vinyl composition tile—0.00878 kg/m2 (0.00079 kg/ft2)
• ceramic tile with recycled windshield glass—0.00311 kg/m2 (0.00028 kg/ft2)
• composite marble tile—0.00311 kg/m2 (0.00028 kg/ft2)
• terrazzo—no installation adhesives
• wool broadloom carpet—1.30932 kg/m2 (0.12164 kg/ft2) traditional/ 0.22260 kg/m2 (0.02068
kg/ft2) low-VOC
• nylon broadloom carpet—3.27320 kg/m2 (0.30409 kg/ft2) traditional/ 0.55650 kg/m2
(0.05170 kg/ft2 low-VOC)
• PET broadloom carpet~~3.27320 kg/m2 (0.30409 kg/ft2) traditional/ 0.55650 kg/m2 (0.05170
kg/ft2) low-VOC
• wool carpet tile—0.24779 kg/m2 (0.02302 kg/ft2) traditional/ 0.04209 kg/m2 (0.00391 kg/ft2)
low-VOC
• nylon carpet tile—0.61946 kg/m2 (0.05755 kg/ft2) traditional/ 0.10527 kg/m2 (0.00978 kg/ft2)
low-VOC
• PET carpet tile—0.61946 kg/m2 (0.05755 kg/ft2) traditional/ 0.10527 kg/m2 (0.00978 kg/ft2)
low-VOC
To assess overall indoor air performance for BEES floor coverings, each product's performance
data for product emissions and installation adhesives are normalized by dividing by the
corresponding performance value for the worst perfc
-------
Wool Brpadloom
Wool Broadloom &
Low-VOC
Nylon Broadloom
Nylon Broadloom &
Low-VOC
PET Broadloom
PET Broadloom &
Low-VOC
Wool Tile
Wool Tile &
Low-VOC
Nylon Tile
Nylon Tile &
Low-VOC
PET Tile
PET Tile/Low-VOC
44.52
44.52
44.52
44.52
44.52
44.52
44.52
44.52
44.52
44.52
44.52 _,
44.52
40.00
6.80
100.00
17.00
100.00
17.0
7.57
1.29
18.92
3.22
18.92
3.22
42.26
25.66
72.26
30.76
72.26
30.76
26.05
22.91
31.72
23.87
31.72
23.87
Interior Wall Finishes. BEES evaluates indoor air performance for interior wall finishes based on
total VOC emissions. Total VOCs for virgin latex paint are estimated to be 100 g/L, and for
recycled latex paint 125 g/L.26 Both paints are initially applied by priming followed by two coats
of paint. For both, one coat is reapplied every 4 years over the 50-year use phase. Based on these
figures, virgin latex paint will emit 13.46 g of VOCs per 0.09 m2 (1 ft2) over 50 years of use, and
recycled latex paint 16.58 g of VOCs per 0.09 m2 (1 ft2) over 50 years. These flows are directly
used to assess indoor air performance for the two interior wall finishes.
Note that due to limitations of indoor air science, the BEES indoor air performance scores
for floor coverings and interior wall finishes are based on heuristics. If the BEES user has
better knowledge, or simply wishes to test the effect on overall results of changes in relative
indoor air performance, these scores may be changed by editing the "total" and "use" columns of
the "Indoor Air" rows of the BEES environmental performance data files.
Wall and Roof Sheathing. Indoor air quality is a concern for many wood products due to their
formaldehyde emissions. Formaldehyde is thought to affect human health, especially for people
with chemical sensitivity. Composite wood products using urea-formaldehyde adhesives have
higher formaldehyde emissions than those using phenol-formaldehyde adhesives, and different
composite wood products have different levels of emissions. Composite wood products include
particleboard, insulation board, medium density fiberboard, oriented strand board (OSB),
hardboard, and softwood and hardwood plywood.
BEES assumes formaldehyde emissions is the only significant indoor air concern for wood
products. BEES currently analyzes two composite wood products—OSB and softwood plywood.
Most OSB is now made using a methylene diphenylisocyanate (MDI) binder, which is the binder
26
Based on data reported in Environmental Building News, Vol. 8, No. 2, February 1999, pp 12,18.
20
Sillli:
Ill Ill,',"" !i;l'!,iii.ji:.";-ii.i IttaJli1 '.:, ijiii','!,::
:,L .iii1,,!; iUiiiiHiili .!!! I.
-------
BEES uses in modeling OSB environmental performance. OSB using an MDI binder emits no
formaldehyde other than the insignificant amount naturally occurring in the wood itself.27
Softwood plywood also has extremely low formaldehyde emissions because it uses phenol-
formaldehyde binders and because it is used primarily on the exterior shell of buildings.28 Thus,
neither of the two composite wood products as modeled in BEES are thought to significantly
affect indoor air quality.
Wall and Ceiling Insulation. Indoor air quality is also discussed in the context of insulation
products. The main issues are the health impacts of fibers, hazardous chemicals, and particles
released from some insulation products. These releases are the only insulation-related indoor air
issues addressed in BEES.
As a result of its listing by the International Agency for Research on Cancer as a "possible
carcinogen," fiberglass products are now required to have cancer warning labels. The fiberglass
industry has responded by developing fiberglass products that reduce the amount of loose fibers
escaping into the air. For cellulose products, there are claims that fire retardant chemicals and
respirable particles are hazardous to human health. Mineral wool is sometimes claimed to emit
fibers and chemicals that could be health irritants. For all these products, however, there should be
little or no health risks to building occupants if they are installed in accordance with
manufacturer's recommendations. Assuming proper installation, then, none of these products as
modeled in BEES are thought to significantly affect indoor air quality.29
Ozone Depletion (assessed for a limited number of BEES products as described in this
section under Classification/Characterization). The ozone layer is present in the stratosphere
and acts as a filter absorbing harmful short wave ultraviolet light while allowing longer
wavelengths to pass through. A thinning of the ozone layer allows more harmful short wave
radiation to reach the Earth's surface, potentially causing changes to ecosystems as flora and
fauna have varying abilities to cope with it. There may also be adverse effects on agricultural
productivity. Effects on man can include increased skin cancer rates (particularly fatal
melanomas) and eye cataracts, as well as suppression of the immune system. Another problem is
the uncertain effect on the climate.
Since the late 1970s, a thinning of the ozone layer over the Antarctic has been observed during
the Spring, which amounts to 80 % to 98 % removal of this layer (the ozone 'hole'). This "hole"
over the Antarctic is created due to the unique chemistry present over the Poles. Under certain
conditions chlorine and bromine (from chlorofluorocarbons—CFCs-and other sources) undergo
complex reactions which result in ozone depletion.
27 Alex Wilson and Nadav Malin, "The IAQ Challenge: Protecting the Indoor Environment," Environmental
Building News, Vol. 5, No. 3, May/June 1996, p 15.
28 American Institute of Architects, Environmental Resource Guide, Plywood Material Report, May 1996.
29 Alex Wilson, "Insulation Materials: Environmental Comparisons," Environmental Building News, Vol. 4,
No. I,pp.l5-16
21
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A single index, expressed in grains of CFC-11 per functional unit of product, is derived to
measure the quantity of CFC-11 with the same potential ozone depleting effect:30
Ozone Depletion index = £i OOP; x nij, where
m, = mass (in grams) of inventory flow i, and ODPj = grams of CFC-11 with the same
ozone depleting potential as one gram of inventory flow i, as listed in table 2.8.
Table 2.8 BEES Ozone Depletion Potential Equivalency Factors
Chemical ODP
Flow Formula (CFC-11 equivalents)
Methyl Bromide
Carbon Tetrachloride
CFC 11
CFC 113
CFC 114
CFC 115
CFC 12
Halon 1201
Halon 1202
Halon 12 11
Halon 1301
Halon 23 11
Halon 2401
Halon 2402
HCFC 123
HCFC 124
HCFC 141b
HCFC 142b
HCFC 22
HCFC 225ca
HCFC225cb
Methyl Chloroform, HC-
140a
CH3Br
CCLt
CFC13
CF2C1CFC12
CF2C1CF2C1
CF3CF2C1
CC12F2
CHF2Br
CF2Br2
CF2ClBr
CF3Br
CF3CHBrCl
CHF2CF2Br
CF2ClBr
CHC12CF3
CHC1FCF3
CFC12CH3
CF2C1CH3
CHF2C1
C3HF5C12
C3HF5C12
CH3CC13
0.37
1.2
1
0.9
0.85
0.4
0.82
1.4
1.25
5.1
12
0.14
0.25
1
o.o i 2
0.026
0.086
0.043
0.034
0.017
0.017
0.11
This method is limited by the following factors:
1. The Ozone Depletion Potentials upon which the assessment method is based are subject to
considerable uncertainty and regular modification.
2. Greenhouse gases can affect the level of ozone directly through chemical reactions or
indirectly by contributing to global warming. At present, the influence of this factor is not
incorporated due to the complex nature of the reactions involved.
30 World Meteorological Organization (WMO), Scientific assessment of ozone depletion, 1991. Updated with
World Meteorological Organization (WMO), Scientific Assessment of Ozone Depletion: 1998, Report 44 (Global
Ozone Research and Monitoring Project).
22
lili •
Mia
-------
3. Concentrations of trace gases such as nitrogen oxides affect atmospheric levels of the
hydroxyl radical (OH), which in turn can affect the atmospheric lifetime of hydrogenated
halocarbons. This process can influence future ozone depletion rates. Thus, ozone depletion
rates may vary with time.
4. ODPs are defined at steady state, and therefore do not represent transient effects. In reality,
shorter-lived halocarbons will reach a "steady state" ability to destroy ozone before longer-
lived compounds. ODPs are based on annually averaged global changes in ozone, which do
not take into account the chemical reactions involving a change in state which occur
specifically at the Poles. Consequently, ODP-derived concentrations tend to understate the
damage to the ozone caused by the presence of chlorine and bromine in the atmosphere.
Smog Formation (assessed for a limited number of BEES products as described in this
section under Classification/Characterization). Under certain climatic conditions, air emissions
from industry and transportation can be trapped at ground level, where they react with sunlight to
produce photochemical smog. One of the components of smog is ozone, which is not emitted
directly, but rather produced through the interactions of volatile organic compounds (VOCs) and
oxides of nitrogen (NOX).
While NOX availability ultimately limits the production of ozone, the reactivity of the VOC
determines the rate at which ozone is produced. Thus, when attempting to quantify smog
potential, not only must the reactivity of the VOC be considered, but also the environmental
conditions (e.g., NOX concentration).
There are a number of difficulties inherent in calculating VOC reactivities, not the least of which is
the non-linear nature of the reactions that produce photochemical smog. This is typified by the
properties of NOX, which can either form ozone or inhibit its formation, depending on the overall
environmental conditions. Additionally, scientists are still not certain of the exact mechanism
underlying ozone formation.
One method that is used to quantify the ozone production potential of various VOCs is based on
the incremental reactivity (IR) scale.31 This scale gives factors for VOCs that indicate the change
in ozone caused by adding a small amount of the compound to the emissions, divided by the
amount added. The resulting factor is generally expressed in moles of ozone formed per gram of
VOC emitted. For the reasons stated above, there are limits to the accuracy of the calculated IR
factors. All the same, government bodies have generally accepted them.32
The US Environmental Protection Agency ranks volatile organic compounds as being either
'negligibly reactive' or 'reactive'. These rankings are used for regulatory control purposes and
31 William P. Carter, "Development of Ozone Reactivity Scales for Volatile Organic Compounds", Journal of
the Air & Waste Management Association, Vol. 44, July 1994, pp. 881-899
32 Dr. Basil Dimitriades, a Senior Scientific Advisor at the Atmospheric Processes Research Division of the US
EPA, stated that while the use of incremental reactivity (IR) factors is not officially sanctioned, when IR data are
presented in reports, they are accepted as being accurate (August 26, 1997). Bart Croes of the California Air
Resources Board (CARB) indicated that MIR factors were specifically used to develop legislation for California
(August 26, 1997).
23
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are based on the reactivity of a compound. Compounds with incremental reactivities less than
that for ethane are considered 'negligibly reactive'.33 This is not to say that these compounds
don't form ozone, they do; they simply produce ozone in small enough amounts that their effect
on overall ozone formation is considered to be inconsequential.
The Maximum Incremental Reactivity (MIR) index is calculated to measure smog formation
potential as follows:
MIR = Ii ms x MIRj, where
mi = mass (in grams) of inventory flow i, and MIR; = Maximum Incremental Reactivity for
inventory flow i.
A partial listing of the 53 flows used in this calculation are shown in Table 2.9.
Table 2.9 Sampling of BEES Maximum Incremental Reactivity Equivalency Factors
Substance
...
Chemical Formula (Maximum Incremental Reactivity)
1-Butanol
2-Methyl 1-Butene
Acetaldehyde
Benzene
Methyl Bromide
1-Butene
Carbon Monoxide
Cyclopentadiene
Dibutyl Ether
1,3-Dimethyl Cyclohexane
Ethane
Ethyl Acetylene
Formaldehyde
Glyoxal
Heptane
Isobutyl Alcohol
Methane
Methyl Cyclopentane
Methyl Glyoxal
1-Nonene
3-Octene
2-Pentene
Styrene
Toluene
Trimethyl Arriine
C4Hi0O
C5Hio
CH3CHO
CfiHe
CH3Br
CH3CH2CHCH2
CO
C5H6
C6H140
C8Hi6
C2H6
C4H6
CH2O
C2H202
C7H16
(CH3)2CHCH2OH
CH4
C6Hi2
C3H4O2
C9Hi8
C8Hi6
CH3CH2(CH)2CH3
C^n.sCnCn.2
CgHsCHs
(CH3)3N
3.324
5.543
6.322
0.601
0.015
10.68
0.061
12.51
2.809
2.586
6.299
11.08
7.009
2.209
1.045
2.332
0.016
3.444
14.32
3.06
7.528
11.79
2.28
3.154
6.699
33
The incremental reactivity for ethane has been estimated to be 0.299 grams ozone per gram VOC.
24
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n-Undecane
Vinyl Acetate
m-Xylene
0.619
6.96
8.82
Ecological Toxicity (assessed for a limited number of BEES products as described in this
section under Classification/Characterization). Ecological toxicity impacts were not included
in BEES 1.0. However, several approaches for ranking chemicals according to relative hazard
have been developed in recent years, in support of waste minimization and pollution
prevention34'35'36 and the Clean Air Act,37 which are potentially applicable in an LCA context.
Research Triangle Institute (RTI) developed the method described below and used in BEES 2.0
after reviewing these sources.
The RTI method includes measurements of relative hazard (toxicity factors or benchmarks) and
environmental fate and transport (persistence and biomagnification factors). The approach
involves the following steps:
1. Screen inventory data by identifying chemical-Specific inventory flows or general
inventory flows that can be represented by a, chemical-specific surrogate, and
eliminate those that are within 15 % of one another.
2. Identify aquatic and terrestrial benchmarks for both acute and chronic toxicity.
3. Assign chemicals a default benchmark if data are missing. The geometric mean of
the available benchmarks is used as the default.
4. Normalize benchmarks within each category based on the geometric mean.
5. Select the maximum normalized benchmark as the toxicity factor.
6. Identify persistence factors for pertinent environmental media.
7. Identify biomagnification factors.
8. Multiply toxicity, persistence, and biomagnification factors for each inventory flow
within each environmental medium for the TPB score.
9. Multiply TPB scores by the inventory mass per functional unit.
10. Sum factors to derive the total terrestrial and aquatic ecological toxicity impact
indicator (ETI).
11. Determine the percentage of each ETI relative to the total ETI and select inventory
flows contributing 0.1 % or more.
12. Compare inventory impacts to total US emissions to determine relative
significance.
34 United States Environmental Protection Agency. Waste Minimization Prioritization Tool, Beta Test Version
1.0: User's Guide and System Documentation, Draft, EPA 530-R-97-019, Office of Solid Waste, Office of
Pollution Prevention and Toxics, Washington, DC, 1997.
35 United States Environmental Protection Agency. Chemical Hazard Evaluation for Management Strategies, A
Method for Ranking and Scoring Chemicals by Potential Human Health and Environmental Impacts, EPA/600/R-
94/177, Office of Research and Development, Washington, DC., 1994. 1
36 Research Triangle Institute. A Multimedia Waste Reduction Management System for the State of North
Carolina, Final Report, Prepared for the North Carolina Department of Health, Environment, and Natural
Resources, Pollution Prevention Program, April, 1993.
37 United States Environmental Protection Agency. Technical Background Document to Support Rulemaking
Pursuant to the Clean Air Act - Section 112(g), Ranking of Pollutants with Respect to Hazard to Human Health,
EPA-450/3-92-010, Office of Air Quality Planning and Standards, Research Triangle Park, NC, 1994.
25
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Table 2.10 gives examples of the 152 RTI ecological toxicity potential equivalency factors used in
BEES to evaluate ecological toxicity for a handful of building products.
: ! i :
Table 2.10 Sampling of Ecological Toxicity Potential Equivalency Factors
II 1 , II
II I l>
III t
Flow(i)
i 'i
Hydrocarbons
Nitrogen Oxides
' Carbon Monoxide
Dioxins
Hydrogen Chloride
Ecotoxicity
(gram's
equivalent
'Ecotoxicity)
21.90
7.30
7.30
20.2x1 08
10.95
Human Toxicity (assessed for a limited number of BEES products as described in this
Section under Classification/Characterization). One approach to developing human toxicity
indicators has been reported by the U.S EPA in Framework for Responsible Environmental
Decision' Making (FRED).38 The FRED approach is based on the belief that industrial systems
often release substances into the environment which can have toxic effects on human beings. In
order for actual effects to occur, exposure to the substance must occur, the substance must be
assimilated, and the received dose to the individual must exceed the body's ability to detoxify it.
There are many potential toxic effects from exposure to industrial and natural substances, ranging
from transient irritation to permanent disability and even death. Some substances have a wide
range of different effects, and different individuals have a widely varying tolerance to different
Substances. Finally, of the millions of industrial chemicals, very few have been subjected to
lexicological evaluation. All these factors make assessments of the human toxicity potential of
given substances difficult at best. When evaluated on a life-cycle basis, evaluating their impact is
even more problematic.
"r , I ,,",'; | i i
Nevertheless, because human toxicity is a real and important environmental issue, the FRED LCA
system incorporated an indicator based on the recommendation of the International Life Sciences
Institute (ILSI), which suggested that all life-cycle human toxicity indicators be based on "No
Observable adverse Effect Levels" (NOELs) and "Lowest Observable Effect Levels" (LOELs).
In other words, toxicity indicators are based on concentrations or doses of chemicals tested on
humans or laboratory animals that caused no effect or minimal effect. Generally, the lower the
NOEL or LOEL, the more toxic the chemical. This approach has been incorporated into the
38 U.S. EPA, Framework for Responsible Environmental Decisionmaking (FRED): Using Life Cycle Assessment
to Evaluate Preferability of Products, Draft Report, by Science Applications International Corporation, Research
Triangle Institute, and EcoSense, Inc, 1999.
26
:;i, ,,'L Wilt I!
it's ti, J'i, i| (,,L
j .-' -
-------
Environmental Defense Fund (EDF) Scorecard developed in conjunction with University of
California at Berkeley. The FRED methodology used the Environmental Defense Fund (EDF)
Scorecard as an indicator of human toxicity. This indicator consists of a pair of measures, one for
carcinogenic and one for non-carcinogenic effects:
Carcinogenic Effects Index = E i Wj x TEP;, where :
Wj=weight of inventory flow i per functional unit of product, and
TEPj = Toxic Equivalency Potential, estimated as the weight of benzene with the same
potential cancer-causing effect as a unit weight of inventory flow i.
Non-Carcinogenic Effects Index = S i w; x TEPj, where
W; = weight of inventory flow i per functional unit of product, and
TEPj = Toxic Equivalency Potential, estimated as the weight of toluene with the same
potential toxic effect as a unit weight of inventory flow i.
Toxic Equivalency Potentials (TEPs) for some of the 174 BEES inventory flows used in this
calculation are given in Table 2.11. hi BEES, the human toxicity impact score is computed by
weighting equally the normalized carcinogenic and non-carcinogenic effects indices.
Table 2.11 Sampling of Human Toxicity Potential Equivalency Factors
TEP (carcinogens) TEP (non-carcinogens)
Flow to Air weight Benzene/ weight Toluene/
weight substance weight substance
Ammonia
Benzene
Formaldehyde
Lead
Phenolics
0
1
0.003
15
0
3.2
17
7
1,300,000
0.045
Flow to Water
TEP (carcinogens)
weight Benzene/
weight substance
TEP (non-carcinogens)
weight Toluene/
weight substance
Ammonia
(Nil, +, NH3 as N)
Benzene
Phenols
0
0.99
0
0.041
11
0.0038
2.1.4 Interpretation
At the LCA interpretation step, the impact assessment results are combined. Few products are
likely to dominate competing products in all BEES impact categories. Rather, one product may
out-perform the competition relative to natural resource depletion and solid waste, fall short
27
-------
relative to global warming and acidification, and fall somewhere in the middle relative to indoor
air quality and eutrophication. To compare the overall environmental performance of competing
products, the performance measures for all impact categories may be synthesized. Note that in
BEES 2.0, synthesis of impact measures is optional.
'• •' . . • : i - |
Synthesizing the impact category performance measures involves combining apples and oranges.
Global warming potential is expressed in carbon dioxide equivalents, acidification in hydrogen
equivalents, eutrophication in phosphate equivalents, and so on. How can the diverse measures of
impact category performance ,be combined into a meaningful measure of overall environmental
performance? The most appropriate technique is Multiattribute Decision Analysis (MADA).
MADA problems are characterized by tradeoffs between apples and oranges, as is the case with
the BEES impact assessment results. The BEES system follows the' ASTM standard for
conducting MADA evaluations of building-related investments.39
';: ' ;"" !
MADA first places all impact categories on the same scale by normalizing them. Within an impact
category, each product's performance measure can be normalized by dividing by the highest
measure for that category, as in the BEES model. All performance measures are thus translated to
the same, dimensionless, relative scale from 0 to 100, with the worst performing product in each
category assigned the highest possible normalized score of 100. Refer to Appendix A for the
BEES environmental performance computational algorithms.
MADA then weights each impact category by its relative importance to overall environmental
performance. In the BEES software, the set of importance weights is selected by the user. Several
derived, alternative weight sets are provided as guidance, and may either be used directly or as a
starting point for developing user-defined weights. The alternative weights sets are based on an
EPA Science Advisory Board study, a Harvard University study, and a set of equal weights,
representing a spectrum of ways in which people value various aspects of the environment.
. . '.•• i j • i
EPA Science Advisory Board study. In 1990, EPA's Science Advisory Board (SAB) developed
lists of the relative importance of various environmental impacts to help EPA best allocate its
resources. The following criteria were used to develop the lists:
• The spatial scale of the impact
» The severity of the hazard
• The degree of exposure
• The penalty for being wrong
.40
Nine of the ten BEES impact categories were among the SAB lists of relative importance:
• Relatively High-Risk Problems: global warming, indoor air quality, ecological toxicity, human
toxicity, ozone depletion, smog
39 American Society for Testing and Materials, Standard Practice for Applying the Analytic Hierarchy Process
to Multiattribute Decision Analysis of Investments Related to Buildings and Building Systems, ASTM Designation
E 1765-95, West Cbnshohocken, PA, 1995.
40 United States Environmental Protection Agency, Science Advisory Board, Reducing Risk: Setting Priorities
'and Stretegies for Environmental Protection, SAB-EC-90-021, Washington, D.C., September 1990, pp 13-14.
28
-------
• Relatively Medium-Risk Problems: acidification, eutrophication
• Relatively Low-Risk Problems: solid waste41
The SAB did not explicitly consider natural resource depletion as an impact. For this exercise,
natural resource depletion is assumed to be a relatively medium-risk problem, based on other
relative importance lists.42
Verbal importance rankings, such as "relatively high-risk," may be translated into numerical
importance weights by following guidance provided by a MADA method known as the Analytic
Hierarchy Process (AHP).43 The AHP methodology suggests the following numerical comparison
scale:
1 Two impacts contribute equally to the objective (in this case environmental performance)
3 Experience and judgment slightly favor one impact over another
5 Experience and judgment strongly favor one impact over another
7 One impact is favored very strongly over another, its dominance demonstrated in practice
9 The evidence favoring one impact over another is of the highest possible order of
affirmation
2,4,6,8 When compromise between values of 1, 3, 5, 7, and 9, is needed.
Through an AHP process known as pairwise comparison, numerical comparison values are
assigned to each possible pair of environmental impacts. Relative importance weights can then be
derived by computing the normalized eigenvector of the largest eigenvalue of the matrix of
pairwise comparison values. Tables 2.12 and 2.13 list the pairwise comparison values assigned to
the SAB verbal importance rankings, and the resulting importance weights computed' for the
BEES impacts, respectively.
Table 2.12 Pairwise Co^ Weights
Verbal Importance Comparison Pairwise Comparison Value
High vs. Medium 2
Medium vs. Low 2
High vs. Low _^__m=_^ _ 4
^/^^
Relative Importance Weight ( %) _
Impact Category
Global Warming
Acidification
6 Impacts
27
13
7 Impacts"
21
11
10 Impacts"
13
6
41 The SAB report classifies solid waste under its low-risk groundwater pollution category (SAB, Reducing Risk,
Appendix A, pp 10-15).
42 See, for example, Hal Levin, "Best Sustainable Indoor Air Quality Practices in Commercial Buildings," Third
International Green Building Conference and Exposition—1996, NIST Special Publication 908, Gaithersburg, MD,
November 1996, p 148.
Thomas L. Saaty, MultiCriteria Decision Making: The Analytic Hierarchy Process—Planning, Priority
Setting, Resource Allocation, University of Pittssburgh, 1988. '.
29
-------
Eutrophication
Natural Resource Depletion
Indoor Air Quality
Solid Waste
Smog
Ecological Toxiciry
Human Toxiciry
Ozone Depletion
13 11
13 11
27 21
7 4
21
6
6
13
4
13
13
13
13
"This set of expanded impacts is available for a limited number of BEES products, as identified in Table 4.1.
Harvard University Study. In 1992, an extensive study was conducted at Harvard University to
establish the relative importance of environmental impacts. The study developed separate
assessments for the United States, The Netherlands, India, and Kenya. In addition, separate
assessments were made for "current consequences" and "future consequences" in each country.
For current consequences, more importance is placed on impacts of prime concern today. Future
consequences places more importance on impacts that are expected to become significantly worse
in the next 2,5 years.
'''" • , ' ' : .1 ' ,!'!', • ' '. 1 .
Nine of the ten BEES impact categories were among the studied impacts. Table 2.14 shows the
Current and future consequence rankings assigned to these impacts in the United States. The study
did not explicitly consider solid waste as an impact. For this exercise, solid waste is assumed to
rank low for both current and future consequences, based on other relative importance lists.45
:•• ;< /":" • • • . • , ;:,t;,(j'V &'*• ] t •'••'.•• ' '. • •' !'
Verbal importance rankings from the Harvard study are translated into numerical, relative
Importance weights using the same, AHP-based numerical comparison scale and pairwise
Table 2.14 U.S. Rankings for Current and Future Consequences by Impact Category
Impact Category Current Consequences
Global Warming
Acidification
Eutrophication
Natural Resource Depletion3
Indoor Air Quality
Smog
Ecological Toxicity
Human Toxicity
Ozone Depletion
Low
High
Medium
Medium
Medium
High
Medium-Low
Medium-Low
Low
Future Consequences
High
Low
Medium
Medium-Low
Low
Low
Medium-Low
Medium-Low
^r—^i^
"Average of consequences for hazards contributing to natural resource depletion.
44 Vicki Norberg-Bohm et al, International Comparisons of Environmental Hazards: Development and
Evaluation of a Method for Linking Environmental Data with the Strategic Debate Management Priorities for Risk
Management, Center for Science & International Affairs, John F. Kennedy School of Government, Harvard
University, October 1992.
45 See, for example, Hal Levin, "Best Sustainable Indoor Air Quality Practices in Commercial Buildings," p
148. As in the SAB report, solid waste is classified under groundwater pollution.
30
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comparison process described above for the SAB study. Sets of relative importance weights are
derived for current and future consequences, and then combined by weighing future consequences
as twice as important as current consequences.46 Table 2.15 lists the resulting importance weights
for the ten BEES impacts. The combined importance weight set is offered as an option in the
BEES software. However the BEES user is free to use the current or future consequence weight
sets by entering these weights under the user-defined software option.
Relative Importance Weight Set
Current
•
Impact Category
Global Warming
Acidification
Eutrophication
Natural Resource Depletion
Indoor Air Quality
Solid Waste
Smog
Ecological Toxicity
Human Toxicity
Ozone Depletion
6
8
33
16
16
16
11
(%)
r
6
25
12
12
12
8
25
Iff1
5
19
9
9
9
7
19
9
9
5
6
38
10
19
14
10
9
Future
(%)
T
35
9
18
13
9
8
7
Iff
22
6
11
8
6
5
5
8
9
20
Combined
6
28
17
18
15
12
10
f °/\
r
25
15
16
13
10
8
13
Iff
16
10
10
9
7
6
10
8
9
15
The Harvard study ranks impacts "high" in future consequences if the current level of impact is expected to
double in severity over the next 25 years based on a "business as usual" scenario. Vicki Norberg-Bohm,
International Comparisons of Environmental Hazards, pp 11-12.
31
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2.2 Economic Performance
Measuring the economic performance of building products is more straightforward than
measuring environmental performance. Published economic performance data are readily
available, and there are well-established ASTM standard methods for conducting economic
performance evaluations. First cost data are collected from the R.S. Means publication, 2000
Building Construction Cost Data, and future cost data are based on data published by Whitestone
Research in The Whitestone Building Maintenance and Repair Cost Reference 1999,
supplemented by industry interviews. The most appropriate method for measuring the economic
performance of building products is the life-cycle cost (LCC) method. BEES follows the ASTM
standard method for life-cycle costing of building-related investments.47
|t is important to distinguish between the tune periods used to measure environmental
performance and economic performance. These time periods are different. Recall that in
environmental LCA, the time period begins with raw material acquisition and ends with product
end-of-life. Economic performance, on the other hand, is evaluated over a fixed period (known as
the study period) that begins with the purchase and installation of the product, and ends at some
point in the future that does not necessarily correspond with product end-of-life.
Economic performance is evaluated beginning at product purchase and installation because this is
when out-of-pocket costs begin to be incurred, and investment decisions are made based upon
out-of-pocket costs. The study period ends at a fixed date in the future. For a private investor, its
length is set at the period of product or facility ownership. For society as a whole, the study
period length is often set at the useful life of the longest-lived product alternative. However, when
all alternatives have very long lives, (e.g., more than 50 years), a shorter study period may be
selected for three reasons:
. i
• Technological obsolescence becomes an issue
• Data become too uncertain
• The farther in the future, the less important the costs
In the BEES model, economic performance is measured over a 50 year study period, as shown in
Figure 2.3 This study period is selected to reflect a reasonable period of time over which to
evaluate economic performance for society as a whole. The same 50 year period is used to
evaluate all products, even if they have different useful lives. This is one of the strengths of the
LGC method. It adjusts for the fact that different products have different useful lives when
evaluating them over the same study period.
For consistency, the BEES model evaluates the use stage of environmental performance over the
same 50 year study period. Product replacements over this 50 year period are accounted for in
the environmental performance score, and end-of-life solid waste is prorated to year 50 for
products with partial lives remaining after the 50 year period.
47 American Society for Testing and Materials, Standard Practice for Measuring Life-Cycle Costs of Buildings
and Building Systems, ASTM Designation E 917-94, West Conshohocken, PA, March 1994.
32
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The LCC method sums over the study period all relevant costs associated with a product.
Alternative products for the same function, say floor covering, can then be compared on the basis
of their LCCs to determine which is the least cost means of providing that function over the study
period. Categories of cost typically include costs for purchase, installation, maintenance, repair,
and replacement. A negative cost item is the residual value. The residual value is the product
value remaining at the end of the study period. In the BEES model, the residual value is computed
by prorating the purchase and installation cost over the product life remaining beyond the 50 year
period.48
Site Selection
and
Preparation
I
»>
rACILITY LIFE CYCLE *
Construction
and Outfitting
A
L
Product
Manufacture
i
L
Raw
Materials
Acquisition
1
ou ycciio -• —
ECONOMIC STUDY PERIOD
Operation
and Use
Renovation
or Demolition
icn \y««- i i~— r»i 1
•ju i ecu uae OLdye
ENVIRONMENTAL
STUDY PERIOD
Figure 2.3 SEES Study Periods For Measuring Building Product Environmental And
Economic Performance
The LCC method accounts for the time value of money by using a discount rate to convert all
future costs to their equivalent present value. Refer to Appendix A for the BEES economic
performance computational algorithm showing the discounting technique.
Future costs must be expressed in terms consistent with the discount rate used. There are two
approaches. First, a real discount rate may be used with constant-dollar (e.g., 2000) costs. Real
discount rates reflect the portion of the time value of money attributable to the real earning power
of money over time and not to general price inflation. Even if all future costs are expressed in
constant 2000 dollars, they must be discounted to reflect this portion of the time-value of money.
Second, a market discount rate may be used with current-dollar amounts (e.g., actual future
prices). Market discount rates reflect the time value of money stemming from both inflation and
the real earning power of money over time. When applied properly, both approaches yield the
48 For example, a product with a 40-year life that costs $10 per 0.09 square meters ($10 per square foot) to
install would have a residual value of $7.50 in year 50, considering replacement in year 40.
33
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same LCC results. The BEES model computes LCCs using constant 2000 dollars and a real
discount rate. As a default, the BEES tool uses a real rate of 4.2 %, the 2000 rate mandated by
the U.S. Office of Management and Budget (OMB) for most Federal projects.49
• »'. • . ,.,,,. ii i i „, i|
„ „ ,'„,'"' I , „ ' '!
2.3 Overall Performance
The BEES overall performance score combines the environmental and economic results into a
single score, as illustrated in Figure 2.4. To combine them, the two results must first be placed on
a common basis. The environmental performance score reflects relative environmental
performance, or how much better or worse products perform with respect to one another. The
economic performance score, the LCC, reflects absolute performance, regardless of the set of
alternatives under analysis. Before combining the two, the life-cycle cost is converted to the same,
relative basis as the environmental score by dividing by the highest-life-cycle cost alternative.
TThen the environmental and economic performance scores are combined into an overall score by
weighting environmental and economic performance by their relative importance values. Overall
scores are thereby placed on a scale from 0 to 100; if a product performs worst with respect to all
environmental impacts and has the highest life-cycle cost, it would receive the worst possible
ciyerall score of 100. The BEES user specifies the relative importance weights used to combine
environmental and economic performance scores and may test the sensitivity of the overall scores
to different sets of relative importance weights. Refer to Appendix A for the BEES overall
performance computational algorithm.
j
2.4 Limitations
Properly interpreting the BEES scores requires placing them in perspective. There are inherent
limits to applying U.S. industry-average LCA and LCC results and in comparing building products
outside the design context.
1 , , : i,, n . . ' 1 ' '!
The BEES LCA and LCC approaches produce U.S. average performance results for generic
product alternatives. The BEES results do not apply to products manufactured in other countries
where manufacturing and agricultural practices, fuel mixes, environmental regulations,
transportation distances, and labor and material markets may differ.50 Furthermore, all products
in an industry-average, generic product group, such as vinyl composition tile floor covering, are
not created equal. Product composition, manufacturing methods, fuel mixes, transportation
practices, useful lives, and cost can all vary for individual products in a generic product group.
thus, the BEES results for the generic product group do not necessarily represent the
performance of an individual product.
i
"" Office of Management and Budget (OMB) Circular A-94, Guidelines and Discount Rates for Benefit-Cost
"Analysis of Federal Programs,Washington, DC, October 27, 1992 and OMB Circular A-94, Appendix C,
February 2000.
50 Since most linoleum manufacturing takes place in Europe, linoleum is modeled based on European
manufacturing practices, fuel mixes, and environmental regulations. However, the BEES linoleum results are only
applicable to linoleum imported into the United States because transport from Europe to the United States is built
into the BEES linoleum data.
34
nil-
i til. , itiLlii
-------
The BEES LCA uses selected inventory flows converted to selected local, regional, and global
environmental impacts to assess environmental performance. Those inventory flows which
currently do not have scientifically proven or quantifiable impacts on the environment are
excluded, such as mineral extraction and wood harvesting which are qualitatively thought to lead
to loss of habitat and an accompanying loss of biodiversity. Ecological toxicity, human toxicity,
ozone depletion, and smog impacts are included in BEES 2.0 for a select set of products (see
table 4.1), but the science and data underlying their measurement are less certain. Finally, since
BEES develops U.S. average results, some local impacts such as resource scarcity (e.g., water
scarcity) are excluded even though the science is proven and quantification is possible. If the
BEES user has important knowledge about these or other potential environmental impacts, it
should be brought into the interpretation of the BEES results.
During the interpretation step of the BEES LCA, environmental impacts are optionally combined
into a single environmental performance score using relative importance weights. These weights
necessarily incorporate values and subjectivity. BEES users should routinely test the effects on the
environmental performance scores of changes in the set of importance weights.
The BEES environmental scores do not represent absolute environmental damage. Rather, they
represent proportional differences in damage, or relative damage, among competing alternatives.
Consequently, the environmental performance score for a given product alternative can change if
one or more competing alternatives are added to or removed from the set of alternatives under
consideration, hi rare instances, rank reversal, or a reordering of scores, is possible. Finally, since
they are relative performance scores, no conclusions may be drawn by comparing scores across
building elements. That is, if exterior wall finish Product A has an environmental performance
score of 60, and roof covering Product D has an environmental performance score of 40, Product
D does not necessarily perform better than Product A (keeping in mind that lower performance
scores are better). The same limitation relative to comparing environmental performance scores
across building elements, of course, applies to comparing overall performance scores across
elements.
There are inherent limits to comparing product alternatives; without reference to the whole
building design context. First, it may overlook important environmental and cost interactions
among building elements. For example, the useful life of one building element (e.g., floor
coverings), which influences both its environmental and economic performance scores, may
depend on the selection of related building elements (e.g., subflooring). There is no substitute for
good building design.
Environmental and economic performance are but two attributes of building product performance.
The BEES model assumes that competing product alternatives all meet minimum
35
-------
t.'1'.til (.1
ill'. J'lll
1
1
I
1
*
-------
technical performance requirements.51 However, there may be significant differences in technical
performance, such as acoustical performance, fire performance, or aesthetics, which may
outweigh environmental and economic considerations.
51 Environmental and economic performance results for wall insulation, roof coverings and concrete beams and
columns do consider technical performance differences. For wall insulation and roof coverings, BEES accounts for
differential heating and cooling energy use. For concrete .beams and columns, BEES accounts for different
compressive strengths.
37
-------
38
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3. BEES Product Data
The BEES model uses the ASTM standard classification system, UNIFORMAT II,52 to organize
comparable building products into groups. The ASTM standard classifies building components
into a three-level hierarchy: major group elements (e.g., substructure, shell, interiors), group
elements (e.g., foundations, roofing, interior finishes), and individual elements (e.g., slab on grade,
roof coverings, floor finishes). Elements are defined such that each performs a given function,
regardless of design specifications or materials used. The UNIFORMAT II classification system is
well suited to the BEES environmental and economic performance methodologies, which define
comparable products as those that fulfill the same basic function. The BEES model uses the
UNIFORMAT II classification of individual elements, the third level of the hierarchy, as the point
of departure for selecting functional applications for BEES product comparisons.
3.1 Portland Cement Concrete Slabs, Walls, Beams, and Columns (BEES
Codes A1030, A2020, B1011, B1012)
Portland cement concrete, typically referred to as "concrete," is a mixture of portland cement (a
fine powder), water, fine aggregate such as sand or finely crushed rock, and coarse aggregate
such as gravel or crushed rock. The mixture creates a semi-fluid material that forms a rock-like
material when it hardens. Note that the terms "cement"' and "concrete" are often used
interchangeably, yet cement is actually only one of several concrete constituents.
Concrete is specified for different building elements by its compressive strength measured 28 days
after casting. Concretes with greater compressive strengths generally contain more cement. While
the compressive strength of concrete mixtures can range fronvO.69 MPa to 138 MPa(100 psi to
20,000 psi), concrete for residential slabs and basements often has a compressive strength of 21
MPa (3000 psi) or less, and concrete for structural applications such as beams and columns often
have compressive strengths of 28 MPa or 34 MPa (4000 psi or 5000 psi). Thus, concrete mixes
modeled in the BEES software are limited to compressive strengths of 21 MPa, 28 MPa, and 34
MPa (3000 psi, 4000 psi, and 5000 psi).
To reduce cost, heat generation, and the environmental burden of concrete, ground granulated
blast furnace slag (referred to as GGBFS or "slag") or fly ash may be substituted for a portion of
the portland cement in the concrete mix. Fly ash is a waste material that results from burning coal
to produce electricity. Slag is a waste material that is a result of steel production. When used in
concrete, slag and fly ash are cementitious materials that can act in a similar manner as cement by
facilitating compressive strength development.
BEES performance data apply to four building elements: 21 MPa (3000 psi) Slabs on Grade and
Basement Walls; and 28 MPa or 34 MPa (4000 psi or 5000 psi) Beams and Columns. For each
52
American Society for Testing and Materials, Standard Classification for Building Elements and Related
Sitework-UNIFORMATII, ASTM Designation E 1557-96, West Conshohocken, PA, 1996.
39
-------
• T i"
building element, concrete alternatives with 100 % cement (no fly ash or slag), 15 %, and 20 %
fly ash content (by weight of cement), and 20 %, 35 %, and 50 % slag content (by weight of
cement) may be compared. While life-cycle costs differ among building elements, the
environmental performance for a given slag or fly ash content and compressive strength rating is
the same. The detailed environmental performance data for all concrete products except concrete
paving53 may be viewed by opening the following files under the File/Open menu item in the
BEES software:
• A103 OA.DBF—Concrete without supplementary cementitious materials
• A1030B.DBF—15 % Fly Ash Content Concrete
• A1030C.DBF—20 % Fly Ash Content Concrete
• A1030D.DBF—20 % Slag Content Concrete
• A1030E.DBF—35 % Slag Content Concrete
• A 1030F.DBF—50 % Slag Content Concrete
Within each of these six environmental performance data files, there are three complete sets of
environmental performance data corresponding to compressive strengtli ratings of 21 MPa, 28
MPa, and 34 MPa (3000 psi, 4000 psi, and 5000 psi).
BEES environmental performance data for concrete products are from the Portland Cement
Association LCA database. This subsection incorporates extensive documentation provided by the
Portland Cement Association for incorporating their LCA data into BEES.54
BEES comparisons for slabs, basement walls, beams, and columns are limited to concrete
products. Thus, for these building elements, the environmental performance data for all concrete
mixes could be modeled from "cradle-to-ready-mix plant gate" rather than from "cradle-to-grave"
as for all other BEES products. That is, environmental flows for transportation from the ready-
mix plant to the building site, installation (including concrete forms, reinforcing steel, welded wire
fabric, and wire mesh), and end of life are ignored. This modeling change does not affect
environmental performance results since BEES assesses relative environmental performance
within a given building element, and there will be no environmental performance differences based
on fly ash or slag content for the ignored life-cycle stages.
Figures 3.1 and 3.2 show the elements of concrete production with and without slag or fly ash.
•: , ;''.: :•;. :' : ' " . '"':' ' "•.'". ' ,!•'. }".' '.• " I
Raw Materials. Table 3.1 shows quantities of concrete constituents for the three compressive
strengths modeled. Other materials that are sometimes added, such as silica fume and chemical
admixtures, are not considered. Typically, fly ash or slag are an equal replacement for cement.
Quantities of constituent materials used in an actual project may vary.
53 The environmental performance of concrete paving products is discussed later in this section.
54 Portland Cement Association, Data Transmittal for Incorporation of Slag Containing Concrete Miy.es into
Version 2.0 of the BEES Software, PCA R&D Serial No. 2168a, PCA Project 94-04, prepared by Construction
Technology Laboratories, Inc. and JAN Consultants, May 2000; and Portland Cement Association, Concrete
Products Life Cycle Inventory (LCI) Data Set for Incorporation into the NlSTBEES Model, PCA R&D Serial No.
2168, PCA Project 94-04a, prepared by Michael Nisbet, JAN Consultants, 1998.
40
-------
Portland Cement. Cement plants are located throughout North America at locations with
adequate supplies of raw materials. Major raw materials for cement manufacture include
Functional Unil
of Concrete
Without
Fly Ash
Portland
Cement
Production
Coarse
Aggregate
Production
Figure 3.1 Portland Cement Concrete Without Fly Ash Flow Chart
limestone, cement rock/marl, shale, and clay. These raw materials contain various proportions of
calcium oxide, silicon dioxide, aluminum oxide, and iron oxidej with oxide content varying widely
across North America. Since portland cement must contain the appropriate proportion of these
oxides, the mixture of the major raw materials and minor ingredients (as required) varies among
cement plants. BEES data for cement manufacture is based on the average raw material mix and
oxide content for all U.S. cement plants for an ASTM C150 Type I/II cement, the most
commonly used cement in North America. The average raw materials for U.S. cement include
limestone, cement rock/marl, shale, clay, bottom ash, fly ash, foundry sand, sand, and iron/iron
ore.
In the manufacturing process, major raw materials are blended with minor ingredients, as
required, and processed at high temperatures in a cement kiln to form an intermediate material
known as clinker. Gypsum is interground with clinker to form Portland cement. Gypsum content
is assumed to be added at 5.15 % (by weight) of portland cement.
Aggregate. Aggregate is a general term that describes a filler material in concrete. Aggregate
generally provides 60 % to 75 % of the concrete volume. Typidally, aggregate consists of a
41
-------
Functional Unit
of
Concrete With
Fly Ash
Portland
Cement
Production
Fly Ash
or Slag
Fine
Aggregate
Production
Coarse
Aggregate
Production
Figure 3.2 Portland Cement Concrete With Fly Ash or Slag Flow Chart
Table 3.1 Concrete Constituent Quantities by Compressive Strength of Concrete
Concrete
Constituent
Cement and Fly Ash or
Slag
Coarse Aggregate
Fine Aggregate
Water
Constituent Weight
in kg per m3
(Ib/yd3)
21MPa
(3000 psi)
223 (376)
1127(1900)
831 (1400)
141 (237)
28MPa
(4000 psi)
279 (470)
1187(2000)
771 (1300)
141 (237)
34MPa
(SOOOpsi)
335 (564)
1187(2000)
712 (1200)
141 (237)
mixture of coarse and fine rocks. Aggregate is either mined or manufactured. Sand and gravel are
examples of mined aggregate. These materials are dug or dredged from a pit, river bottom, or
lake bottom and require little or no processing. Crushed rock is an example of manufactured
aggregate. Crushed rock is produced by crushing and screening quarry rock, boulders, or large-
sized gravel. Approximately half of the coarse aggregate used in the United States is crushed
rock.
i !
i '
Fly Ash. Fly ash is a waste material that results from burning coal to produce electricity, hi LCA
terms, fly ash is an environmental outflow of coal combustion, and an environmental inflow of
concrete production. As in most LCAs, this waste product is assumed to be an environmentally
42
-------
"free" input material.55 However, transport of the fly ash to the ready mix plant is included.
Slag. Slag is a waste material, which is a result of the production of steel. Similar to fly ash, slag
is an environmental outflow of steel production and an environmental inflow of concrete
production. Therefore, slag is considered to be an environmentally "free" input material.55 Unlike
fly ash, slag must be processed prior to inclusion in concrete. Processing consists of quenching
and granulating at the steel mill, transport to the grinding facility, and finish grinding.
Transportation to the ready mix plant is included.
Energy Requirements: Portland Cement. Portland cement is manufactured using one of four
processes: wet process, dry process, preheater, or preheater/precalciner. The wet process is the
oldest and uses the most energy due to the energy required to evaporate the water. New cement
manufacturing plants are being constructed, and older plants converted, to use the more energy
efficient preheater or preheater/precalciner processes. As of 1995, the mix of production
processes was 30 % wet, 27 % dry, 19 % preheater, and 24 % preheater/precalciner. Table 3.2
presents U.S. industry-average energy use by process and fuel type, and, for all processes
combined, average energy use weighted by the 1996 process, mix. Note that the production of
waste fuels is assumed to be free of any environmental burdens to portland cement production
(LCA dictates that waste fuel production burdens be allocated to the product whose manufacture
generated the waste fuels).
Table 3.2 Energy Requirements for Portland Cement Manufacturing
Fuel Use
Coal
Petroleum Coke
Natural Gas
Liquid Fuels**
Wastes
Electricity
All Fuels:
Total Energy in kJ/kg
of cement (Btu/lb)
Cement Manufacturing Process*
Wet
49
18
9
1
16
7
100
6838 (2940)
Dry
45
31
8
1
6
9
100
6117(2630)
Preheater (
67
6
10
2
4
12 :
100 :
4885 (2100):
Precalciner
60
8 •
16
1
3
12
100
4699 (2020)
Weighted
Average
54
17
11
1
8
10
100
5745 (2470)
Cement constitutes only 10 to 15 % by weight of concrete's total mass.
Liquid fuels include gasoline, middle distillates, residual oil, and liquefied petroleum gas
Aggregate. In BEES, coarse and fine aggregate are assumed to be crushed rock, which tends to
slightly overestimate the energy use of aggregate production. Production energy for both coarse
55 .
' The environmental burdens associated with waste products are typically allocated to the products generating
the waste.
43
-------
imp
and fine aggregate is assumed to be 155 kJ/kg of aggregate (66.8 Btu/lb).
i i
Fly Ash. Fly ash is a waste material with no production energy burdens.
Slag. Similar to fly ash, slag is a waste material and therefore does not include energy burdens
associated with steel production. Because slag requires processing prior to incorporation into
concrete, the energy use for granulation and grinding are included. Production energy is assumed
to be 465 kJ/kg of slag (200 Btu/lb).
, , n , ^ , , i „ , , i
Round-trip distances for transport of concrete faw materials to the ready mix plant are assumed to
be 97 km (60 mi) for portland cement and fly ash, 216 km (134 mi) for slag, and 80 km (50 mi)
for aggregate. The method of transport is truck, consuming 1.18 kJ/kg*km (0.818 Btu/lb*mi).
• i
Concrete. In BEES, concrete is assumed to be produced in a central ready-mix operation. Energy
use in the batch plant includes electricity and fuel used for heating and mobile equipment. Average
energy use is assumed to be 247 MJ/m3 of concrete (0.179 MBtu/yd3, or about 45 Btu/lb of
concrete).
• • . • • • ' i • . ' (•
{ i
Emissions. Emissions for concrete raw materials are from the Portland Cement Association
cement LCA database. Emissions include particulate matter, carbon dioxide (CO2), carbon
monoxide (CO), sulfur oxides (SOx), nitrogen oxides (NOx), total hydrocarbons, and hydrogen
chloride (HC1). Emissions vary for the eighteen different mixtures of compressive strength and fly
ash or slag content as shown in the concrete environmental performance data files.
Cost. The detailed life-cycle cost data for concrete products may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Life-cycle cost data
include first cost data (purchase and installation costs) and future cost data (cost and frequency of
3replacement, and where appropriate and data are available, of operation, maintenance, and repair).
Costs are listed under the BEES codes listed hi Table 3.3. First cost data are collected from the
i
R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are based on
data published by Whitestone Research in The Whitestone Building Maintenance and Repair Cost
Reference 1999, supplemented by industry interviews.
Table 3.3 BEES Life-Cycle Cost Data Specifications and Codes for Concrete Products
Concrete Product
0 % Fly Ash Content Slab on Grade
15 % Fly Ash Content Slab on Grade
20 % Fly Ash Content Slab on Grade
0 % Fly Ash Content Basement Wall
15 % Fly Ash Content Basement Wall
20 % Fly Ash Content Basement Wall
0 % Fly Ash Content Beams
15 % Fly Ash Content Beams
20 % Fly Ash Content Beams
0 % Fly Ash Content Columns
Specification
10.2cm-15.2cm (4"-6") thick
10.2cm-15.2cm (4"-6") thick
10.2cm-15.2cm (4"-6") thick
20.3-38. 1cm (8"-l 5") thick
20.3-38. 1cm (8"-15") thick
20.3-38.1cm(8"-15") thick
3.0-7.6 m (10'-25') span
3.0-7.6 m (10'-25') span
3.0-7.6 m (10'-25') span
40.6-6 1.0cm (16"-24") diameter
BEES Code
A1030,AO
A1030,BO
A1030,CO
A2020.AO
A2020,BO
A2020,CO
B1011,AO
B1011,BO
B1011.CO
B1012,AO
44
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15 % Fly Ash Content Columns
20 % Fly Ash Content Columns
40.6-6 1.0cm (16"-24") diameter
40.6-61.0cm (16"-24") diameter
B1012,BO
B1012,CO
3.2 Roof and Wall Sheathing Alternatives (B1020, B2015)
3.2.1 Oriented Strand Board Sheathing (B1020A, B2015A)
Oriented strand board (OSB) is made from strands of low density wood. A wax, primarily a
petroleum-based wax, is used to bind the strands. Resins, mainly phenolic resin with some
Memylene Diphenyl Isocyanate (MDI) resin, are also used as a binder material in making most
OSB. For the BEES system, 1.1 cm (7/16 in) thick OSB boards are studied. The flow diagram in
Figure 3.3 shows the major elements of oriented strand board production.
BEES performance data are provided for both roof and wall sheathing. Life-cycle costs differ for
the two applications, while the environmental performance data are assumed to be the same. The
detailed environmental performance data for OSB roof and wall sheathing may be viewed by
opening the file B1020A.DBF under the File/Open menu item in the BEES software.
Raw Materials. Energy use for timber production is based on ;studies by Forintek and Procter &
Gamble.56 The average energy use reported is 200 MJ per 907 kg (95 Btu/lb) of greenwood
produced, assumed to be in the form of diesel fuel for tractors. Tailpipe emissions from tractors
and emissions associated with production of diesel fuel are included based on the Ecobalance
LCA database. :
BEES also accounts for the absorption of carbon dioxide by trees. The "uptake" of carbon
dioxide during the growth of timber is assumed to be 1.74 kg of carbon dioxide per kg of
greenwood harvested. The volume of wood harvested is based on an average density of 500
kg/m3 (31 lb/ft3), with aspen at 450 kg/m3 (28 lb/ft3) and Southern yellow pine at 550 kg/m3 (34
Ib/ft3).
Transportation of Raw Materials to Manufacturing Plant. For transportation of raw materials
to the manufacturing plant, BEES assumes truck transportation of 161 km (100 mi) for wood
timber and truck transportation of 322 km (200 mi) for both the resins and the wax. The tailpipe
56 Ash, Knoblock, and Peters, Energy Analysis of Energy from the Forest Options, ENFOR Project P-59, 1990; B.
N. Johnson, "Inventory of Land Management Inputs for Producing Absorbent Fiber for Diapers: A Comparison of
Forest Products Journal, vol 44, no. 6, 1994.
45
-------
Timber
Production
1
Transportation
(track)
161 km (100 mi)
Resin Production
i
Transportation T
(truck)
322 km (200 mi) 32
Electricity
Production
L^
• 1
cturing
Transportation
(50% rail/50% track)
161-805-1609 km sensitivity
(100-500-1000 mi)
Petroleum
Wax
Production
1 r if
ransportation
(truck)
2 km (200 mi)
•Ir
Installation — Waste-*
\
,
Figure 3.3 Oriented Strand Board Flow Chart
gmissions fi;qni the trucks and the emissions from producing the fuel used
into account based on the Ecobalance database.
in the trucks are taken
Manufacturing. The components and energy requirements for OSB manufacturing are based on a
study performed by the United States Department of Agriculture (USDA).^7 Table 3.4 shows the
Ipristituents of OSB production.
Table 3.4 Oriented Strand Board Sheathing Constituents
Component
. ( ' i!1 „
..•Wood
Resin
- Wax
Total:
Input
(kg/kg product)
1.365
0.023
0.010
1.398
In Final Product
(kg/kg)
0.967
0.023
0.010
In Final
Product (%)
96.7
2.3
1.0
'100" •
There is no waste from the OSB manufacturing process. All the input resin (mainly phenolic resin
with some Methylene Diphenyl Isocyanate (MDI) resin) and the wax are assumed to go into the
final product and the excess wood material is assumed to be burned on site for fuel.
The energy for the OSB manufacturing process is generated from burning the wood waste and
from purchased electricity. The amount of electricity used is assumed to be 612 MJ/kg (263.2
"Spelter H, Wang R, and Ince P, Economic Feasibility of Products from Inland West Small-Diameter Timber,
IJnited States Department of Agriculture, Forest Service ( May 1996).
46
,;{',; i, i K'J (I
-------
Btu/lb) of OSB produced.
The emissions from the OSB manufacturing process are based on a Forintek Canada Corporation
Study, as reported in Table 3.5.58 Since these emissions are assumed to be from combustion of the
wood residue and any volatile organic compound (VOC) emissions from drying the OSB, the
carbon dioxide (CO2) emissions are all assumed to be biomass-based. VOC emissions are reduced
by 30 % to account for process improvements over time. Electricity production emissions are
based on a standard US electricity grid.
Table 3.5 Oriented Strand Board Manufacturing Emissions
ValUe
Emission (per oven dry tonne of OSB)
Carbon Dioxide
Carbon Monoxide
Methane
Nitrous Oxides
Sulfur Dioxide
Volatile Organic
Compounds
Particulates
488 kg (1'076 lb)
91 g (3.2 oz)
43g(l,5oz)
685 g (24.2 oz)
159g(5.6oz)
161 g (5.7 oz)
502 g (17.7 oz)
The resin used in OSB production is assumed to be 80 % phenolic resin and 20 % Methylene
Diphenyl Isocyanate. Data representing the production of both resins are derived from the
Ecobalance database.
The wax used in the production of OSB is assumed to be petroleum wax. Production of the
petroleum wax is based on the Ecobalance database and includes the extraction, transportation,
and refining of crude oil into petroleum wax. :
Transportation from Manufacturing to Use. Transportation of OSB to the building site is
modeled as a variable of the BEES system, with equal portions by truck and rail. Emissions
associated with the combustion of fuel in the train and truck engines are included as are the
emissions associated with producing the fuel, both based on the Ecobalance database.
Installation: Installation waste with a mass fraction of 0.015 is .assumed.
Cost. Installation costs for OSB sheathing vary by application. The detailed life-cycle cost data for
this product may be viewed by opening the file LCCOSTS.DBF under the File/Open menu item in
the BEES software. Its costs are listed under the following codes:
• B1020,AO—Oriented Strand Board Roof Sheathing
58 Forintek Canada Corporation, Building Materials in the Context of Sustainable Development: Raw Material
Balances, Energy Profiles and Environmental Unit Factor Estimates for Structural Wood Products, March 1993, p
27.
47
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• B2015,AO—Oriented Strand Board Wall Sheathing
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
(cost and frequency of replacement, and where appropriate and data are available, of operation,
maintenance, and repair). First cost data are collected from the R.S. Means publication, 2000
Building Construction Cost Data, and future cost data are based on data published by Whitestone
Research in The Whitestone Building Maintenance and Repair Cost Reference 1999,
supplemented by industry interviews.
3.2.2 Plywood Sheathing (B1020B, B2015B)
'.'..'. '.. . , . '. I '
Plywood sheathing is made from lower density wood. Phenol formaldehyde is used in the
manufacturing process. For the BEES system, 1.3 cm (1/2 in) thick plywood boards are studied.
The flow diagram shown in Figure 3.4 shows the major elements of plywood sheathing
production.
BEES performance data are provided for both roof and wall sheathing. Life-cycle costs differ for
the two applications, while the environmental performance data are assumed to be the same. The
detailed environmental performance data for plywood roof and wall sheathing may be viewed by
opening the file B 1020B.DBF under the File/Open menu item in the BEES software.
Raw Materials. BEES accounts for energy use during timber production. Energy use was based
gri studies by Forintek and Procter & Gamble.59 The average energy use reported was 200 MJ
per 907 kg (95 Btu/lb) of greenwood produced, assumed to be in the form of diesel fuel for
tractors. Tailpipe emissions from tractors and emissions associated with production of diesel fuel
are included based on the Ecobalance LCA database.
• ' ' ' .,....,]
' • • ": | ' •• i
BEES also accounts for the absorption of carbon dioxide by trees. The "uptake" of carbon
dioxide during the growth of timber is assumed to be 1.74 kg of carbon dioxide per kilogram of
greenwood harvested. The volume of wood harvested is based on an average density of 600
kg/m3 (37.5 lb/ ft3).
Transportation of Raw Materials to Manufacturing Plant For transportation of raw materials
to the manufactiipng plant, BEES assumes truck transportation of 161 km (100 mi) for wood
timber and truck transportation of 322 km (200 mi) for the resin. The tailpipe emissions from the
trucks and the emissions from producing the fuel used in the trucks are taken into account based
ori the Ecobalance database.
t
59 Ash, Knoblock, and Peters, Energy Analysis of Energy from the Forest Options, ENFOR Project P-59,1990; B.
N. Johnson, "Inventory of Land Management Inputs for Producing Absorbent Fiber for Diapers: A Comparison of
Cotton and Softwood Land Management," Forest Products Journal, vol 44, no. 6, 1994.
48
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Transportation
(truck)
161 km (100 mi)
Transportation
(truck)
322 km (200 mi)
Electricity
Production
Manufacturing
Transportation
(50% rail/50% truck)
161-805-1609 km sensitivity
(100-500-1000 mi)
-Waste>
Figure 3.4 Plywood Sheathing Flow Chart
Manufacturing. The components and energy requirements for plywood manufacturing are based
on a Forintek Canada Corporation study60. Table 3.6 shows the constituents of plywood
production.
Table 3.6Plywood Constituents
Constituent
Input
(kg/kg product)
In Final Product
(kg/kg)
In Final
Product ( %)
Wood
Resin
Total:
1.51
0.101
1.611
0.899 :
0.101
1
89.9
10.1
100
There is no waste from the plywood manufacturing process. All the input resin, phenol
formaldehyde, is assumed to go into the final product and the residual wood material in the form
of bark and wasted veneers is assumed to be burned on site for fuel (except for some waste
veneer's cores, which are normally sold for landscaping limber or converted into chips for pulp).
The energy for the plywood manufacturing process is generated from burning the wood waste and
from purchased electricity. The amount of electricity used is based on the Forintek study and is
assumed to be 351 MJ per oven dry tonne (151 Btu/lb) of plywood produced. Electricity
production emissions are based on a standard U.S. electricity grid. The emissions from the
60 Forintek Canada Corporation, Building Materials in the Context of Sustainable Development: Raw Material
Balances, Energy Profiles and Environmental Unit Factor Estimates for Structural Wood Products, March 1993,
pp 20-24.
49
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plywood manufacturing process are based on the Forintek Canada Corporation study, as reported
in Table 3.7.
.' , ' . „„ 'ii1 ' 'i
Table 3.7 Plywood Manufacturing Emissions
Emission
Carbon Dioxide
Carbon Monoxide
Methane
Nitrous Oxides
Sulfur Dioxide
Volatile Organic
Compounds
Particulates
Amount
-i j
(per oven dry tonne of plywood)
500 kg (1162.3 Ib)
112 g (3.95 oz)
35g(1.2oz)
668g(23.6oz)
30 g (1.1 oz)
408 g (14.4 oz)
699 g (24.7 oz)
Since emissions are assumed to be from combustion of the wood residue and any VOC emissions
from drying the plywood, COa emissions are all assumed to be biomass-based.
.. . .
The glue used in bonding plywood consists of phenolic resin in liquid form combined with
extender (dry fibers) assumed to be caustic soda. Data for the production of this glue are based
on the Ecobalance database.
Transportation from Manufacturing to Use. Transportation of plywood to the building site is
modeled as a variable of the BEES system, with equal portions by truck and rail. Emissions
associated with the combustion of fuel in the train and truck engines are included as are the
emissions associated with producing the fuel, both based on the Ecobalance database.
Installation. Installation waste with a mass fraction of 0.015 is assumed.
j
Cost. Installation costs for plywood vary by application. The detailed life-cycle cost data for this
product may be viewed by opening the file LCCOSTS.DBF under the File/Open menu item in the
BEES software. Its costs are listed under the following codes:
• B1020,60—Plywood Roof Sheathing
• B2015,BO—Plywood Wall Sheathing
• . •...•. • , • i i j ,i
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
(cost and frequency of replacement, and where appropriate and data are available, of operation,
maintenance, and repair). First cost data are collected from the R.S. Means publication, 2000
Building Construction Cost Data, and future cost data are based on data published by Whitestone
Research in The Whitestone Building Maintenance and Repair Cost Reference 1999,
supplemented by industry interviews.
50
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3.3 Exterior Wall Finish Alternatives (B2011)
3.3.1 Brick and Mortar (B2011A)
Brick is a masonry unit of clay or shale, formed into a rectangular shape while plastic, then burned
or fired in a kiln. Mortar is used to bond the bricks into a single unit. Facing brick is used on
exterior walls for an attractive appearance.
For the BEES system, solid, fired clay facing brick (10 cm x 6.8 cm x 20 cm, or 4 in x 2-2/3 in x 8
in) and Type N mortar are studied. The flow diagram shown in Figure 3.5 shows the major
elements of clay facing brick and mortar production. The detailed environmental performance data
for this product may be viewed by opening the file B2011 A.DBF under the File/Open menu item
in the BEES software.
Brick and Mortar
Natural
Gas
Production
Clay Mining
T
Electricity'
Production
Coal
Production
Diesel Fuel
Production
1
Sawdust
Production
Electricity
Production
Fuel Oil
Production
Figure 3.5 Brick and Mortar Flow Chart
Raw Materials. Production of the raw materials for brick and mortar are based on the Ecobalance
LCA database. Type N mortar consists of 1 part (by volume) masonry cement, 3 parts sand,61 and
6.3 L (1.67 gal) of water. Masonry cement is modeled based on the assumptions outlined below
for stucco exterior walls.
61 Based on ASTM Specification C 270-96.
51
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Energy Required. The energy requirements for brick production (drying and firing) are listed in
Table 3.8. The production of the different types of fuel is based on the Ecobalance LCA database.
Table 3.8 Energy Requirements for Brick Manufacturing
Fuel Use Manufacturing Energy
Total Fossil Fuel
% Coal
% Natural Gas*
% Fuel Oil
% Wood
2.88 MJ/kg(l,238 Btu/lb)
9.6 %
71-9%
7.8%
10.8 %
* Includes Propane
The mix of brick manufacturing technologies is 73 % tunnel kiln technology and 27 % periodic
kiln technology.
The mortar is assumed to be mixed in a 5.9 kW (8 hp), gasoline powered mixer with a flow rate
of 0.25 m3 (9 ft3) of mortar per hour, running for five minutes.
Emissions. Emissions are based on AP-4262 data for emissions from brick manufacturing for each
manufacturing technology and type of fuel burned.
Transportation. Transportation of the raw materials to the brick manufacturing facility is not
Jaken into account (often manufacturing facilities are located close to mines). However,
transportation to the building site is modeled as a variable. Bricks are assumed to be transported
by truck and train (86 % and 14 %, respectively) to the building site. The BEES user can select
from among three travel distances.
i
Use. The density of brick is assumed to be 2.95 kg (6.5 Ib) per brick. The density of the Type N
mortar is assumed to be 2002 kg/m3 (125 lb/ft3). A brick wall is assumed to be 80 % brick and 20
% mortar by surface area.
I
End-Of-Life. The brick wall is assumed to have a useful life of 100 years. Seventy-five percent
of the bricks are assumed to be recycled after the 100 year use.
i
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code B2011, product code 10. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building. Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
62 United States Environmental Protection Agency, Clearinghouse for Inventories and Emission Factors, Version
6.0, EPA 454/C-98-005, Emission Factor and Inventory Group, October 1998.,
52
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3.3.2 Stucco (B2011B)
Stucco is cement plaster used to cove]: exterior wall surfaces. For the BEES system, three coats
of stucco (two base coats and one finish coat) are studied. A; layer of bonding agent, polyvinyl
acetate, is assumed to be applied between the wall and the first layer of base coat stucco.
Figures 3.6 and 3.7 show the elements of stucco production:from both portland cement (for a
base coat Type C plaster, finish coat Type F plaster) and masonry cement (for a base coat Type
MS plaster, finish coat Type F plaster). Since both cements are commonly used for stucco
exterior walls, LCA data for both portland cement and masonry cement stucco were collected and
then averaged for use in the BEES system.
The detailed environmental performance data for stucco exterior walls may be viewed by opening
the file B2011B.DBF under the File/Open menu item in the BEES software.
Raw Materials. The raw material consumption for masonry cement is based on Type N masonry
cement as shown in Table 3.9. ;
Table 3.9 Masonry Cement Constituents
Masonry Cement Constituent Physical Weight
%)
Portland Cement Clinker
Limestone
Gypsum
50
47.5
2.4
Production of these raw materials is based on the Ecobalarice LCA database.
1 '•
Stucco consists of the raw materials listed in Table 3.10.63
The coat of bonding agent is assumed to be 0.15 mm (0.006 in) thick. The bonding agent is
polyvinyl acetate.
Production of sand, lime, and polyvinyl acetate is based on the Ecobalance database.
Energy Requirements. The energy requirements for masonry cement production are shown in
Table 3.11.
63
Based on ASTM Specification C 926-94.
53
-------
'"'I fvi'i
, ,n f!
BondngAgenl
Pffifl<«*>n
• , I - •".? , .
GUiyte) a Acffllfe add Oxygen
Production Production Production
"
EMctrtdty Electricity
Production Production
'"I: "l|."! '"
1 '• ' ' ' /!"'"! > '!• '•'",' , ;'! '! ' '' i
,,,,,,,' " ^ ,, ^n, ^ ' L , ;,' '.
'I'?'1' 'I'''' ! , ']
Stucco
FffirJonalUnit,
Exteriw Wall " '^'V "' V"V ,;,,,,, „ ; ,„ , , , ,
i
Stucco (Type C) , J™^ Stucco (Type F) ,_ j^L
Production (Raw Mail's) Production (RawMati's)
1 ' . t ' '
T t .
1 1 . ; 1
Hydrated Portland Sand Gaso|ine Hydrated Portland Sgnd Gaso|ine
Drtvi^i D r^i • Mining Production D ^ ?. D ^. Mining Production
1 -I ;; . . ..
, • t ,
Electricity
Production
Electricity Electricity bectricity
Production Production Production
: ,; , ! "' •' ' ' " ' :',„ ' : '' "''"' "' " ! ' ' '" "'
Figure 3.6 Stucco (Type C) Flow Chart
,1 ' illq ,
Bonding Agent
Production
••
•"• 1 1
Clhytef HJ Acotic add Oxygen
Production Production Production
T " I
Etedrfdty Eloctricity
Production Production
„ ' '", 'i, : i" ". "i, :
Stucco
• • „ , - ,'•,',"', • f ' • .
Functional Unit of ;
Stucco E d f LifQ ;
Exterior Wall * End of Lifo ,
• i
1
. ' niJj;
,
•
1 ,
.' ,„ .,
Stucco (Type MS) T nj . Stucco (Type F) T *** net
Production (Ra^MaU'sj. Productron , (R^^ffs)
1
" . " .i . ,
1 1
Masonry Sand Gasoline csmam Sand (Sasoline
ProluSlon Mlnina Production Production Minn9 Production
r T
Electricity Electricity
Production Production
,,,,,, , , , ., , , , ! , ,
Figure 3.7 Stucco (Type MS) Flow Chart
Table 3.10 Stucco Constituents
Type of Stucco
Cetnenfitious Materials (parts by volume)
Portland Masonry Lime
Cement Cement
Sand
per volume of
cementitious mat'I
Base Coat C
1
0.5
3.75
54
-------
Finish Coat F
Base Coat MS
Finish Coat FMS
1.125
2.25
3.75
2.25
Table 3.11 Energy Requirements for Masonry Cement Manufacturing
Fuel Use Manufacturing Energy
Total Fossil Fuel 2.72 MJ/kg (1169 Btu/lb)
%Coal 84 ;
% Natural Gas 7
% Fuel Oil 1
% Wastes 8
Total Electricity 0.30 MJ/kg (129 Btu/lb)
These percentages are based on average fuel use in portland cement manufacturing.
Stucco is assumed to be mixed in an 5.9 kW (8 hp), gasoline powered mixer with a flow rate of
0.25 m3 (9 ft3) of stucco per hour, running for five minutes.
Emissions. Emissions for masonry cement production are based on AP-42 data for controlled
emissions from cement manufacturing. Clinker is assumed to be produced in a wet process kiln.
Transportation. Transportation distance to the building site is modeled as a variable.
Use. The thickness of the three layers of stucco is assumed to be 1.6 cm (5/8 in) each. The
densities of the different types of stucco are shown in Table 3.12.
Table 3.12 Density of Stucco by Type
Density
Type of Stucco kg/0.0283m3 (lb/ ft3)
Base Coat C 51.79(114.18)
Finish Coat F 55.78 (122.97)
Base Coat MS 53.97 (118.98)
Finish Coat FMS 61.55 (135.69)
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code B2011, product code 20. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair).1 First, cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
55
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3.3.3 Aluminum Siding (B2011C)
Aluminum siding is a commonly-used exterior wall cladding. Aluminum siding is very attractive
for its weight and durability, weighing less and lasting longer than traditional wood and vinyl
siding. The manufacture of any aluminum product consists of many steps - crude oil production,
distillation and desalting, hydrotreating of crude oil, salt mining, caustic soda manufacturing,
limestone mining, lime manufacture, bauxite mining, alumina production, coal mining, coke
production, aluminum smelting, and ingot casting. For the BEES system, 0.061 cm (0.024 in)
thick, 20 cm (8 in) wide horizontal siding, is studied. The aluminum siding is assumed to be
fastened with aluminum nails 41 cm (16 in) on center. The flow diagram in Figure 3.8 shows the
major elements of aluminum siding production.
Functional Unit of
Aluminum Siding
Aluminum Nail
Production
Aluminum Siding
Production
Figure 3.8 Aluminum Siding Flow Chart
. , I
Raw Materials. There are a number of aluminum siding products on the market, each with
different proprietary ingredients. The product studied for the BEES system is manufactured as an
aluminum sheet with a Polyvinyl Chloride (PVC) thermoset topcoat. Table 3.13 presents the
major constituents of aluminum siding. Production requirements for these constituents are based
on the Ecobalance LCA database.
Table 3.13 Aluminum Siding Constituents
Constituent
Percent Weight %
Aluminum Sheet
PVC Topcoat
99
1
Transportation. Transport of PVC from its production site to the aluminum siding manufacturing
plant is taken into account. Transportation of manufactured aluminum siding by heavy-duty truck
56
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to the building site is modeled as a variable of the BEES system. Emissions associated with the
combustion of fuel in the track engines are included, as are the emissions associated with fuel
production, both based on the Ecobalance LCA database.
Use. Installation waste with a mass fraction of 0.05 is assumed.
3.3.4 Cedar Siding (B2011D)
Cedar wood is ideal for exterior siding because it is a lightweight, low-density material that
provides adequate weatherproofing. It also provides an attractive exterior wall finish. As with
most wood products, cedar siding production consist of three major steps. First, roundwood is
harvested from logging camps. Second, logs are sent to sawmills and planing mills where the logs
are washed, debarked, and sawed into planks. The planks are edged, trimmed, and dried in a kiln.
The dried planks are then planed and the lumber sent to a final trimming operation. Third, lumber
from the sawmill is shaped into fabricated, milled wood products.
For the BEES system, beveled cedar siding 1.3 cm (H in) thick and 15 cm (6 in) wide is studied.
Cedar siding is assumed to be installed with galvanized nails 41 cm (16 in) on center and finished
with one coat of primer and two coats of stain. Stain is reapplied every ten years. The flow
diagram in Figure 3.9 shows the major elements of cedar siding production.
Functional Unit of
Cedar Siding
Wood Primer
Production
Wood Stain
Production
Cedar Wood
Siding Production
Figure 3.9 Cedar Siding Flow Chart
Raw Materials. Production data for cedar wood is derived from the Ecobalance LCA database.
Energy Requirements. The energy requirements for cedar siding manufacture are approximately
57
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i'-ll* ' I!
5.6 MJ/kg (2,413 Btu/lb) of cedar siding produced.64 Table 3.14 shows the breakdown by fuel
type. BEES data for production and combustion of the natural gas, heavy fuel oil, and liquid
petroleum fuels used for cedar siding production are based on the Ecobalance database.
Table 3.14 Energy Requirements for Cedar Siding Manufacture
Fuel Use65
Manufacturing Energy
Total Fossil Fuel
% Natural Gas
% Heavy Fuel Oil
% Liquid Petroleum Gas
% Hogfuel
5.6 MJ/kg (2,413 Btu/lb)
39.8
' 4'!i
" ' 4.1
52
il ! I
Emissions. The hogfuel emissions from the cedar sawmill are listed in Table 3.15.
in; , Table 3.1'5 Hogfuel Emissions66
Emission
Amount
g/MJ wood burned (oz/kWh)
Carbon Dioxide
Carbon Monoxide (CO)
Methane (CHLO
I* !iiii||!i<|" 'i"'IJ!'i!|!'l ' • ' i i' iii • ' i
Nitrogen Oxides (NOx)
Sulfur Oxides (SOX)
Volatile Organic Compounds (VOC)
flrtiqulates
81.5(10.35)
o.mi(o.ool4)
0.008 (o.doi)
6.1 io (0.614)
0.0002 (0.000525)
0.039 (0.005)
0.708(0.09)
Transportation. Since sawmills are typically located close to the forested area, transportation of
faW rnatenals to the sawmill is not taken into account. Transport of primer and stain to the
manufacturing plant is included. Transport of cedar siding by truck to the building site is modeled
as a variable of BEES. Emissions associated with the combustion of fuel in the truck engine are
included, as are the emissions associated with producing the fuel. Both sets of emissions data are
based on the Ecobalance database.
Use. The density of cedar siding at 12 % moisture content is assumed to be 449 kg/ m3 (28 lb/
ft3). At installation, 5 % waste is assumed.
3.3.5 Vinyl Siding (B2011E)
^ Building Materials in the Context of Sustainable Development - Raw Material Balances, Energy Profiles and
Environmental Unit Factor Estimates for Structural Wood Products, March 1993.
*s Excluding electricity
* Building Materials in the Context of Sustainable Development - Raw Material Balances, Energy Profiles and
"EnvironmentalUnit Factor Estimates for Structural Wood Products, op cit.
58
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Vinyl siding is attractive for its low maintenance, and cost. Durability under exposure to a wide
variety of weather conditions is another key attraction. Like all plastic materials, vinyl results from
a series of processing steps that convert hydrocarbon-based raw materials (petroleum, natural gas,
or coal) into polymers. The vinyl polymer is based in part on hydrocarbon feedstocks: ethylene
obtained by processing natural gas or petroleum. The other part of the vinyl polymer is based on
the natural element chlorine. Inherent in the vinyl manufacturing process is the ability to
formulate products of virtually any color with any number of performance qualities—including
ultraviolet light stabilization, impact resistance, and flexibility—in virtually any size, shape, or
thickness. . '
Vinyl siding is manufactured in a wide variety of profiles, colors, and thickness' to meet different
market applications. For the BEES system, 0.11 cm (0.0428 in) thick, 23 cm (9 in) wide
horizontal vinyl siding installed with galvanized nail fasteners is studied. The fasteners are
assumed to be placed 41 cm (16 in) on center. Figure 3.10 shows the major steps for vinyl siding
production.
Functional Unit of
PVC Siding
Galvanized Nail
Production
Figure 3.10 Vinyl Siding Flow Chart
Raw Materials. Polyvinyl chloride (PVC) is the main component in the manufacture of vinyl
siding. Titanium dioxide (TiO2) is a chemical additive that is used in the siding as a pigment or
bleaching agent. Table 3.16 presents 1he proportions of PVC and titanium dioxide in the siding
studied. Data representing the production of raw materials for vinyl siding are based on the
Ecobalance database.
59
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Table 3.16 Vinyl Siding Constituents
Constituent
Percent by Weight ( %)
Polyvinyl Chloride (PVC)
Titanium Dioxide (TiOa)
80
20
Transportation. Transportation of raw materials to the manufacturing plant is taken into account.
Transportation oFttie manufactured siding to the building site by heavy-duty truck is modeled as a
Variable of BEES. Emissions associated with the combustion of fuel in the truck engine are
included, as are emissions associated with fuel production. Emissions data are derived from the
Ecobalance database.
Use. At installation, 5 % of the product is lost to waste.
I ;, -i'll ' > , . ' !' ' ' . . '• ,' !J, „ •' . "i: i I " . •• :' •; ]
1 . i! mi:;!'", ' li!; ,,i , ' . " ' , , ' .1 m1 ' : I ,!
"', ' ,fi , -" ' , '!,'• " • ' , , . ,, •".,: ., , r |(i . , |
3.4 Wall and Ceiling Insulation Alternatives (B2012, B3012)
3.4.1 Blown Cellulose Insulation (B2012A, B3012A)
Blown cellulose insulation is produced primarily from post-consumer wood pulp (newspapers),
typically accounting for roughly 80 % of the insulation by weight. Cellulose insulation is treated
with fire retardant. Ammonium sulfate, borates, and boric acid are used most commonly and
account for the other 20 % of the cellulose insulation by weight. The flow diagram shown in
Figure 3.11 shows the elements of blown cellulose insulation production.
BEES performance data are provided for thermal resistance values of R-13 for a wall application
and R-30 for a ceiling application. The amount of cellulose insulation material used per functional
unit is shown in Table 3.17, based on information from the Cellulose msulation Manufacturers
Association (CIMA).
i i
The detailed environmental performance data files for this product may be viewed by opening the
following files under the File/Open menu item in the BEES software:
t B2012A.pBFMR/-13 Blown Cellulose Wall Insulation
V B30i2A.bBF—-R-30 Blown Cellulose Ceiling Insulation
i
Transportation of Raw Materials to Manufacturing. Transport of raw materials to the
manufacturing plant is taken into account, assuming truck transportation of 161 km (100 mi) for
wastepaper and truck transportation of 322 km (200 mi) for both the ammonium sulfate and the
boric acid. The tailpipe emissions from the trucks and the emissions from producing the fuel used
in the trucks are based on the Ecobalance database.
Manufacturing. The constituents for cellulose insulation manufacture are based on information
from CIMA, as shown in Table 3.18.
60
i :
-------
Ammonium Sulfate
Production
Transportation
(truck)
161 km (100 mi)
Transportation
(truck)
322km (200 mi)
Transportation
: (truck)
322. km (200 mi)
80-322-483 km sensitivity ;
Waste -*•
Figure 3.11 Blown Cellulose Insulation Flow Chart
Table 3.17Blown Cellulose Mass by Application
Application
Wall (R-13)
Ceiling (R-30)
Thickness
cm (in)
8.9 (3.5)
20.6 (8.1)
Density Mass per Functional Unit
kg/m3 (lb/f?) kg/m2 (oz/tf)
25.6(1.6)
25.6(1-6) :
2.26 (7.41)
5.27 (17.28)
Table 3.18 Blown Cellulose Insulation Constituents
Constituent
Wastepaper
Ammonium Sulfate
Boric Acid
Total:
Input
(kg/kg product)
0.80
0.155
0.045
1.0
In Final Product ( %)
80
15.5
; 4,5
100
There are no wastes or water effluents from the manufacturing process. Manufacturing energy is
61
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ed to come from purchased electricity. The amount of electricity used is based on CIMA
pata 'an'fi' a |gquirement of 035 MJ per kg (150 Btu per Ib) of cellulose insulation produced.
Electricity production emissions are based on the Ecobalance database and a standard U.S.
electricity grid.
The only burdens for production of wastepaper are those associated with collection and
transportation of wastepaper to the manufacturing facility.
Ammonium sulfate is assumed to be produced as a co-product of caprolactam production. The
materials and energy used by the process are based on the Ecobalance database.
The boric acid used in the manufacture of cellulose insulation is assumed to be produced from
Jjorax. production of boric acid is based on the Ecobalance database.
Transportation from Manufacturing to Use. Transport of cellulose insulation to the building
Site by truck is modeled as a variable of BEES, based on a range of likely distances (80 km, 322
|m, and 483 Jkm, or 50 mi, 200 mi, and 300 mi) provided by CIMA. Emissions associated with
combustion of fuel in the truck engine are included as are the emissions associated with producing
the fuel. Emissions data are derived from the Ecobalance database.
Since it is assurne4 that all three insulation materials studied (cellulose, fiberglass, and mineral
wool) have similar packaging requirements, no packaging burdens are taken into account.
Installation. At installation, 5 % of the product is lost to waste. The energy required for blowing
the insulation is included, assuming the insulation is blown at a rate of 1134 kg (2,500 Ib) per hour
lising energy provided by a diesel truck. BEES accounts for emissions associated with burning
3iesel fuel in a reciprocating engine, as well as emissions associated with producing the diesel fuel.
'Use. It is important to consider thermal performance differences when assessing environmental
and econcHrj|c performance for insulation product alternatives. Thermal performance affects
building heating and cooling loads, which in turn affect energy-related LCA inventory flows and
Building energy costs over the 50 year use stage. Since alternatives for ceiling insulation all have
JR-30 thermal resistance values, thermal performance differences are at issue only for the wall
insulation alternatives.
]por wall insulation, thermal performance differences are separately assessed for 14 U.S. cities
spread across a wide range of climate and fuel cost zones, and for electricity, distillate oil, and
natural gas neating fuel types (electricity is assumed for all cooling). When selecting wall
insulation alternatives for analysis, the BEES user selects the US. city closest to the building
location and the building heating fuel type, so that thermal performance differences may be
customized to these important contributors to building energy use. A NlST study of the economic
efficiency of energy conservation measures (including insulation), tailored to these cities and fuel
types, is used to estimate 50 year heating and cooling requirements per functional unit of
62
!;.',:!' -.:
'I .',,;;«,
-------
insulation.67 BEES environmental performance results account for the energy-related inventory
flows resulting from these energy requirements. To account for the 50 year energy requirements
in BEES economic performance results, 1997 fuel prices by State68 and U.S. Department of
Energy fuel price projections over the next 30 years69 are used to compute the present value cost
of operational energy per functional unit for each alternative R-value.
Cost. Installation costs for blown cellulose insulation vary by application. The detailed life-cycle
cost data for this product may be viewed by opening the file LCCOSTS.DBF under the File/Open
menu item in the BEES software. Its costs are listed under the following codes:
• B2012,AO—R-13 Blown Cellulose Wall Insulation
• B3012,AO—R-30 Blown Cellulose Ceiling Insulation
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
(cost and frequency of replacement, and where appropriate and data are available, of operation,
maintenance, and repair). Operational energy costs for wall insulation (discussed above under
"Use") are found in the file USEECON.DBF. All other future cost data are based on data
published by Whitestone Research in The Whitestone Building Maintenance and Repair Cost
Reference 1999, supplemented by industry interviews. First cost data are collected from the R.S.
Means publication, 2000 Building Construction Cost Data.
3.4.2 Fiberglass Batt Insulation (B2C12B, B2012C, B2012E, B3012B)
Fiberglass batt insulation is made by forming spun-glass fibers into batts. Using a rotary process,
molten glass is poured into a rapidly spinning disc that has thousands of fine holes in its rim.
Centrifugal force extrudes the molten glass through the holes, creating the glass fibers. The fibers
are made thinner by jets, air, or steam and are immediately coated with a binder and/or de-dusting
agent. The material is then cured in ovens and formed into batts. The flow diagram in Figure 3.12
shows the elements of fiberglass batt insulation production.
BEES performance data are provided for thermal resistance values of R-l 1, R-13, and R-15 for a
wall application, and R-30 for a ceiling application. The amount of fiberglass insulation material
used per functional unit is shown in Table 3.19. The detailed environmental performance data for
this product may be viewed by opening the following files under the File/Open menu item in the
BEES software:
Stephen R. Petersen, Economics and Energy Conservation in the Design of New Single-Family Housing,
NBSIR 81-2380, National Bureau of Standards, Washington, D.C., 1981. i
68 Therese K. Stovall, Supporting Documentation for the 1997 Revision to the DOE Insulation Fact Sheet,
ORNL-6907, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 1997.
69 Sieglinde K. Fuller, Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis—April 1997,
NISTIR 85-3273-12,-National Institute of Standards and Technology, 1997. The year 30 DoE cost esclation factor
is assumed to hold for years 31-50.
63
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Sand
Production
Borax
Production
Limestone
Production
Phenol
Formaldehyde
Production
Transportation
(truck)
402 km (250 mi)
Transportation
(truck)
161 km (100 mi)
ninn.« Pill
Transportation
(train)
805 km (500 mi)
Transportation
!;; (truck)
161 km (100 mi)
/
,11,
Transportation
(truck)
322 km (200 mi)
. ' ". • ,,;, -ft 'I i.;
Figure 3.12 Fiberglass Batt Insulation Flow Chart
9 B2012B.DBF—R-l 1 Fiberglass Batt WaU Insulation
• B2012E.DBF—R-13 Fiberglass Batt Wall Insulation
• B20i2abBI^-R-15 Fiberglass Batt:Wall Insulation
!» B3012B.pBF—R-30 Fiberglass Batt Ceiling Insulation
Table 3.19 Fiberglass Batt Mass by Application
Application
Wall-R-11
Wall-R-13
Wall--R-15
Ceiling-R-30
Thickness
cm (in)
8.9 (3.5)
8.9 (3.5)
8-9 (3.5)
22.9 (9.0)
Density Mass per Functional Unit
kg/m3 (Ib/ff) kg/m2 (oz/f?)
8.0 (0.5)
12.8(0.8)
24.0(1.5)
8.0(0.5)
0.71 (2.33)
1.18(3.88)
2.15(7.05)
1.83(6.0)
Raw Materials. Fiberglass baits are composed of the materials listed in Table 3.20. Production
requirements for these materials are based on the Ecobalance LCA database.
64
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Table 3.20 Fiberglass Batt Constituents
Constituent
Physical Weight (
'
Borax
Glass Gullet
Limestone
Phenol Formaldehyde
Sand
'6.9
6.2
50
'.5.9
'•31
Fiberglass batt production involves the energy requirements as listed in Table 3.21.
Table 3.21 Energy Requirements for Fiberglass Batt Insulation Manufacturing
Fuel Use Manufacturing Energy
Electricity 0.13 MJ/kg fiberglass (56 Btu/lb)
Natural Gas 6 MJ/kg fiberglass (2,580 Btu/lb)
Emissions. Emissions associated with fiberglass batt insulation manufacture are based on AP-42
data for the glass fiber manufacturing industry.
Use. It is important to consider thermal performance differences when assessing environmental
and economic performance for insulation product alternatives. Thermal performance affects
building heating and cooling loads, which in turn affect energy-related LCA inventory flows and
building energy costs over the 50 year use stage. Since alternatives for ceiling insulation all have
R-30 R-values, thermal performance differences are ait issue only for the wall insulation
alternatives.
For wall insulation, thermal performance differences are separately assessed for 14 U.S. cities
spread across a wide range of climate and fuel cost zones, and for electricity, distillate oil, and
natural gas hearing fuel types (electricity is assumed for all cooling). When selecting wall
insulation alternatives for analysis, the BEES user selects the U.S. city closest to the building
location and the building heating fuel type, so that thermal performance differences may be
customized to these important contributors to building energy use. A NIST study of the economic
efficiency of energy conservation measures (including insulation), tailored to these cities and fuel
types, is used to estimate 50 year heating and cooling requirements per functional unit of
insulation.70 BEES environmental performance results account for the energy-related inventory
flows resulting from these energy requirements. To account for the 50 year energy requirements
in BEES economic performance results, 1997 fuel prices by State71 and U.S. Department of
Stephen R. Petersen, Economics and Energy Conservation in the Design of New Single-Family Housing,
NBSIR 81-2380, National Bureau of Standards, Washington, B.C., 1981.
71 Therese K. Stovall, Supporting Documentation for the 1997 Revision to the DOE Insulation Fact Sheet,
OKNL-6907, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 1997^
65
-------
!' : "i
Energy fuel price projections over the next 30 years72 are used to compute the present value cost
pf operational energy per functional unit for each R-value.
When installing fiberglass batt insulation, approximately 2 % of the product is lost to waste.
Xltjiougn fiSerglass insulation reuse or recycling is feasible, very little occurs now. Most
fiberglass insulation waste is currently disposed of in landfills.
.;, • ; , ••• • ,;;('',; fji • :i • - • ..r ,'..'•' : i , " , :" ' 'i;. • ';:, ••,•... ; i1 | .' ,•' ' ( \
Cost. Purchase and installation costs for fiberglass batt insulation vary by R-value and application.
The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOST S.DBFunder the File/Open menu item in the BEES software. Its costs" are listed under
the following codes:
s B2012,60—R-il Fiberglass Batt Wall Insulation
S B2012SEO^R-13 Fiberglass Batt Wall Insulation
• B26l2,S5—1-IS Fiberglass"Batt Wail Insulation
i B3012,BJ)--]fr30 Fiberglass Batt Ceiling Insulation
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
(cost and frequency of replacement, and where appropriate and data are available, of operation,
maintenance, and repair). Operational energy costs for wall insulation (discussed above under
"Use") are founci ^ me file USEECON.DBF. All other future cost data are based on data
j i
published by Whitestone Research in The Whitestone Building Maintenance and Repair Cost
Reference 1999, supplemented by industry interviews. First cost data are collected from the R.S.
Means publication, 2000 Building Construction Cost Data.
3.4.3 Blown Fiberglass Insulation (B3012D)
Blown fiberglass insulation is made by forming spun-glass fibers using the same method as for
batts but leaving the insulation loose. Using a rotary process, molten glass is poured into a rapidly
thinning disc that has thousands of fine holes in its rim. Centrifugal force extrudes the molten
glass through the holes, creating the glass fibers. The fibers are made thinner by jets, air, or steam
and are immediately coated with a binder and/or de-dusting agent
„ . - i
The flow diagram in Figure 3.13 shows the elements of blown fiberglass insulation production.
BEES performance data are provided for a thermal resistance value of R-30 for a ceiling
application. The amount of fiberglass insulation material used per functional unit is shown in
Table 3.22. The detailed environmental performance data for blown fiberglass insulation may be
viewed by opening the file B3012D.DBF under the File/Open menu item in the BEES software.
72 Sieglinde K. Fuller, Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis—April 1997,
NISTER. 85-3273-12, National Institute of Standards and Technology, 1997. The year 30 DoE cost esclation factor
IS assumed to hold for years 31-50.
11 ""ill!, i; "vsi'iiiiiiiii
66
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Sand.
Production
Borax
Production
Limestone
Production _
Phenol
Formaldehyde
Production
Transportation
(truck)
402 km (250 mi)
Transportation
(truck)
161 km (100 mi),
Transportation
(train)
805 km (500 mi)
Transportation
(truck]
161 km (100 mi)
Transportation
(truck)
322 km (200 mi)
Figure 3.13 Blown Fiberglass Insulation Flow Chart
Table 3.22 Blown Fiberglass Mass
Application
Ceiling (R-30)
------- -VJ ___ .............
Thickness Density Mass per Functional Unit
cm (in) kg/m3 (Ib/ff) kg/m2 (oz/ff)
22.9 (9.0)
12.0 (0.75)
2.8(9.17)
Raw Materials. Blown fiberglass is composed of the materials listed in Table 3.23.
Table 3.23 Blown Fiberglass Constituents
Constituent Physical Weight ( %)
Borax
Glass Cullet
Limestone
Phenol Formaldehyde
Sand
6.9
6.2'
50:
5.9
31'
Production requirements for fiberglass insulation constituents are based on the Ecobalance LCA
database. ;
Fiberglass production involves the energy,requirements as listed in Table 3.24.
67
-------
Table "3.24 Energy Requirements for Fiberglass Insulation Manufacturing
;::-:. Fuel Use _ Manufacturing Energy _
Electricity 0.13 MJ/kg fiberglass (56 Btu/lb)
•;•' '. I 1 ";;: Natural Gas 6 MJTkg fiberglass (2,580 Btu/lb)
................... ......... ...... , , ,. , . i , . , , . i
i
Emissions. Emissions associated' with fiberglass insulation manufacture are based on AP-42 data
fpr the glass fiber manufacturing industry.
i' ill1' ili if '• ," ",i '> i*"!! ll'i ....... n ! ' ', • . 'i i ' ' • • ; ..... " , ' ' ' " • • ,1 '"i"! > ill!!!'1 ,• : ' i "I ':, l|." ' ' .,'' , ..... ' 'H . I „ ill' 1
U^ef It is important to recognize thermal performance differences when assessing environmental
arid economic performance for insulation product alternatives. Thermal performance affects
building heating and cooling loads, which in turn affect energy-related LCA inventory flows and
building energy costs over the 50 year use stage. However, since alternatives for ceiling insulation
all have R-30 R-values, there are no thermal performance differences for this application.
""•• ' '•',• ;.": -™ " • . ••• .•"; ; . "V . "• ," •.•..•r-1 1-1, :" -t' ;.;.:••• ,• " .'• ',-.'• '. 5;;
( i
X/hen installing blown fiberglass insulation, approximately 5 % of the product is lost to waste.
Although fiberglass insulation reuse or recycling is feasible, very little occurs now. Most
fiberglass insulation waste is currently disposed of in landfills. Energy for blowing the insulation is
Included, based on a 18 kW (25 hp) diesel engine blowing 1134 kg (2,500 Ib) of fiberglass
insulation per hour.
1 1 ''' 1 ' ' ' ' ' ' ' ' ' ' '
The d'etailed life-cycle cost data for this product may be viewed by opening the file
ECCOSf S.l5lF under the File?Open menu item in the BEES software. Its costs are listed under
IB ill1!, '"Mi: ; ! ', • ,, I'1! 'tilli i ' i1!!!"!*! "Ti,, ..... ''•»., „" i 111"* ' Ml! Ir1 '!' " " ,„ > ...... , •, ' ,m, : , ,» i,,' ......... , , M, , ' i," 'V^ ':v „,' 'A Mir ........... ....... »i i ...... • •< „ , ....... ,..' • n „ u •, ..... if .,• . "• ' ;• • ..... • '-i • -» " ..... ' ]| •
BEES code B3012.DO. Life-cycle cost data include first cost data (purchase and installation
costs) and future cost data (cost and frequency of replacement, and where appropriate and data
are available, of operation, maintenance, and repair). All other future cost data are based on data
published by Whitestone Research in The Whitestone Building Maintenance and Repair Cost
Reference 1999, supplemented by industry interviews. First cost data are collected from the R.S.
Means publication, 2000 Building Construction Cost Data.
3.4^4 Blown Mineral Wool insulation (B2012D, B3012C)
Blown mineral wool insulation is made by spinning fibers from natural rock (rock wool) or iron
iimil.jnfiit,,,!,,1 ,: ,„,, ,,,';i,|' ?'!' ., n,: nill'dU il!:'iilill!:l!ili ' "I'1'"',,,, v „ MI n, i ni.",',' .;!!!"' (,;' i! ^ ' ,!!!"' ,»!, i!'"i n, ."•" ,• III,L « ,,i •: 'iM1 • "jii " ,, , I'll"1, ":» in, n '"HI i '• * MI r - f 11 • n i, ^ u • •• •• - j
pfe blast furnace sjag (slag wool). Rock wool and slag wool are manufactured by melting the
gonstituent jgw materials in a cupola. A molten stream is created and poured onto a rapidly
spinning wheel or wheels. The viscous molten material adheres to the wheels and the centrifugal
force throws droplets of melt away from the wheels, forming fibers. The fibers are then collected
and cleaned to remove non-fibrous material. During the process a phenol formaldehyde binder
and/or a de-dusting agent are applied to reduce free, airborne wool during application. The flow
diagram in Figure 3.14 shows the elements of blown mineral wool insulation production.
ii i nil1 in illirui11
"•It I. ''••'' Ili
68
-------
Transportation
(truck)
161 km (100 mi)
P
Use
Diabase Rock
Production
>
Transportation 7
(truck)
: 161 km (100 mi) 32
ron „ ag
Electricity
Production
Coke
Production
8C
Diesel Fuel
in Installation
1 V '
' i '
j Mineral Wool
j-> Insulation
; Manufacturing
j
i
Transportation
(truck)
-322-483 km sensitivity
(50-200-300 mi)
|
1
Phenol
;ormaldehyde
Production
I
v :
"ransportation
(truck) '
.2 km (200 mi)
;
-> ':
Figure 3.14 Blown Mineral Wool Insulation Flow Chart
BEES performance data are provided for a thermal resistance value of R-12 for a wall application,
and R-30 for a ceiling application. The detailed environmental performance data for blown
mineral wool insulation may be viewed by opening the following files under the File/Open menu
item in the BEES software:
• B2012D.DBF—R-12 Blown Mineral Wool Wall Insulation
• B3012C.DBF—R-30 Blown Mineral Wool Ceiling Insulation
Raw Materials. Mineral wool insulation is composed of the materials listed in Table 3.25.
Production requirements for the mineral wool constituents are based on the Ecobalance LCA
database.
Table 3.25 Blown Mineral Wool Constituents
Mineral Wool Constituents
Phenol Formaldehyde
Iron-ore slag (North American)
Diabase/basalt
Physical Weight ( %)
2.5
78
20
Mineral wool production involves the energy requirements listed in Table 3.26.
Emissions. Emissions associated with mineral wool insulation production are based on AP-42
data for the mineral wool manufacturing industry.
69
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Table 3.26 Energy Requirements for Mineral Wool Insulation Manufacturing
iFuel tfse Manufacturing Energy
Electricity 1.0 MJ/kg(430 Btu/lb)
..'. "& :.i: , Coke 6.38 MJ/kg (2,743 Btu/lb)
Use. It is important to consider thermal performance differences when assessing environmental
and economic performance for insulation product alternatives. Thermal performance affects
building heating and cooling loads, which in turn affect energy-related LCX inventory flows and
building energy costs over the 50 year use stage. Since alternatives for ceiling insulation all have
R-30 R- values, thermal performance differences are at issue only for wall insulation alternatives.
wall insulation, thermal performance differences are separately assessed for 14 U.S. cities
spread across a wide range of climate and fuel cost zones, and for electricity, distillate oil, and
natural gas heating fuel types (electricity is assumed for all cooling). When selecting wall
insulation alternatives for analysis, the BEES user selects the U.S. city closest to the building
location and the building heating fuel type, so that thermal performance differences may be
customized to these important contributors to building energy use. A NIST study of the economic
efficiency of energy conservation measures (including insulation), tailored to these cities and fuel
types, is used to estimate 50 year heating and cooling requirements per functional unit of
Insulation.7* BEES environmental performance results account for the energy-related inventory
flows resulting from these energy requirements. To account for the 50 year energy requirements
in BEES economic performance results, 1997 fuel prices by State74 and U.S. Department of
Energy fuel price projections over the next 30 years75 are used to compute the present value cost
of operational energy per functional unit for each R- value.
Mineral wool insulation is typically blown into place. It is assumed to be blown at a rate of 1 134
kg/h (2,500 Ib/h) with a 25 horsepower diesel engine. During installation, 5 % of the product is
lost to waste.
Purchase and installation costs for blown mineral wool insulation vary by application. The
detailed life-cycle cost data for this product may be viewed by opening the file LCCOSTS.DBF
under the File/Open menu item in the BEES software. Its costs are listed under the following
codes:
• B2012.DO—R-12 Blown Mineral Wool Wall Insulation
• B3012,CO—R-30 Blown Mineral Wool Ceiling Insulation
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
(cost and frequency of replacement, and where appropriate and data are available, of operation,
73 Stephen R. Petersen, Economics and Energy Conservation in the Design of New Single-Family Housing,
NBSIR 81-2380, National Bureau of Standards, Washington, D.C., 1981.
7* Therese K. Stpyall, Supporting Documentation for the 1997 Revision to the DOE Insulation Fact Sheet,
ORNL-6907J'<5akRidge National LaboratoVJ Oak'^'dge, tennessee,''19971 " ' '" "
;' 7S Sieglinde K, Fuller, Energy Price Indices and Discount Factors for Life-Cycle Cost Analysis—April 1997,
HJSTIR 85-3273-12, National Institute of Standards and Technology, 1997. the year 30 DoE cost escalation factor
JS assumed to hold for years 31-50.
70
-------
maintenance, and repair). Operational energy costs for wall insulation (discussed above under
"Use") are found in the file USEECON.DBF. All other future cost data are based on data
published by Whitestone Research in The Whitestone Building Maintenance and Repair Cost
Reference 1999, supplemented by industry interviews. First cost data are collected from the R.S.
Means publication, 2000 Building Construction Cost Data.
3.5 Framing Alternatives (B2013)
3.5.1 Steel Framing (B2013A)
Steel is an important construction framing material. Steel is made from iron, which in turn is made
from iron ore, coal, and limestone in the presence of oxygen. The steel-making process includes
the processing of iron ore, coal, and limestone prior to a blast furnace operation, which makes the
raw material, iron. Other materials used in steel manufacturing processes include nickel,
manganese, chromium, and zinc, as well as various lubricating oils, cleaning solvents, acids, and
alkalines.
Cold-formed steel framing is manufactured from blanks sheared from sheets that are cut from
coils or plates, or by roll-forming cold or hot-rolled coils or sheets. Both these forming
operations are done at ambient temperatures. Light-gauge steel shapes are formed from flat-
rolled 12- to 20-gauge carbon steel as either single bent shapes or bent shapes welded together.
Two basic types of steel framing, nailable and nonnailable, are available in both punched and solid
forms. Zinc chromate primer, galvanized, and painted finishes are available. Steel stud and joist
systems have been adopted as an alternative to wood and masonry systems in most types of
construction. Steel framing is also used extensively for interior partitions because it is fire-
resistant, easy to erect, and makes installation of utilities more convenient. Light-gauge steel
framing can be installed directly at the construction site or it can be prefabricated off- or on-site.
The assembly process relies on a number of accessories usually made of steel, such as bridging,
bolts, nuts, screws, and anchors, as well as devices for fastening units together, such as clips and
nails. ;
In recent years, structural steel has increasingly been used for framing systems due to its fire
resistance and high strength-to-weight ratio. For the BEES system, 18-gauge (1.1 mm, or 0.0428
in thick) steel studs and tracks are evaluated. Tracks are sized to fit the studs. Self-tapping steel
screws, used as fasteners for the steel studs, are included. Figure 3.15 shows the elements of steel
framing production. The detailed environmental performance data for this product may be viewed
by opening the file B2013A.DBF under the File/Open menu item in the BEES software:
Raw Materials. Production of the raw materials necessary for steel stud manufacture is based on
data from the American Iron and Steel Institute (AISI). Four North American steel companies
provided primary data for the production of hot-rolled coil, while data for cold-rolled steel and
71
-------
1"
Functional Unit of
Steel Framing
Figure 3.15 Steel Framing Flow Chart
hot dip galvanized steel came from three sites. Further primary data was collected for some
upstream processes, such as iron ore mining and lime production. Secondary data were obtained
from LCA databases and literature. The steel is assumed to be made of steel produced from the
fiasic Oxygen Furnace (BOF) process, which includes roughly 20 % recycled material.
•. ' "" i ' i
'«!»'1 '• n» ' '»•; "";,!!!„!!!!! ,,, 'i!,!!.!"!ll!i! ! • ,' •",« • . ' ' • ,' ','! 'i! ,!' ' , ' ' '!" '.!!" • ''!'! •! , 1 !'!'"'» • "",!' «< ,1 ' !'"',!• "'i' "' i" j
Fasteners are produced largely from recycled material, and are produced primarily in Electric Arc
Furnaces (EAF). European data are used for the production of steel fasteners76.
Energy Requirements. Energy requirements for producing steel are based on the European data
source listeS above, combined with upstream U.S. energy production models in the Ecobalance
EC A database... { ^ ' i , .' .. '. ,.. '," ','",. "„ ' . . , ,'. '['.
Emissions. Emissions for steel stud and self-tapping screw production are based on the
Ecobalance LCA database.
•
' I
Transportation. Transport of steel raw materials to the manufacturing plant is included.
Transport of steel framing by heavy-duty truck to the building site is a variable of the BEES
model. Emissions associated with the combustion of fuel in the truck engine and with production
of the fuel are included, based on the Ecobalance database.
, , • ', . .1 i
Use. Use of steel framing for exterior walls without a thermal break such as rigid foam may
increase thermal insulation requirements or otherwise adversely affect building thermal
performance. While this interdependency of building elements is not accounted for in BEES 2.0, it
will be considered in the future as the BEES system moves beyond building products to building
systems and components.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in'the" BEES software. Its costs are listed under
BEE$ code "82013,, product code AO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
Slid data are available, of operation, maintenance, and repair). First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
76 Swiss Federal Office of Environment, Forests and Landscape (FOEFL or BUWAL), Environmental Series
No. 250.
72
-------
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
3.5.2 Wood Framing (B2013B)
Wood framing is the most common structural system used for hon-load-bearing and load-bearing
interior walls, and includes lumber, constructed truss products, and specific applications of treated
lumber. Floor framing consists of a system of sills, girders, subflooring, and joists or floor trusses
that provide support for floor loads and walls. There are two types of interior partitions: bearing
partitions, which support floors, ceilings, or roofs, and nonbearing partitions, which carry only
their own weight. The sole plate and the top plate frame the wall structure of vertical studs, and
sheathing or diagonal bracing ensures lateral stability. In general, dimensions for framing lumber
are given in nominal inches (i.e., 2 x 4 x 6). Framing lumber must be properly grade-marked to be
acceptable under the major building codes. Such grade marks identify the grade, species or
species group, seasoning condition at time of manufacture, producing mill, and the grading rules-
writing agency.
Wood studs are produced in a sawmill, where, harvested wood is debarked and sawn into specific
dimensions. The lumber is then dried in a controlled environment until the desired moisture
content (between 12 % and 19 %) is reached. It is possible to treat framing lumber with
preservatives in order to guard against insect attack, or to shield against surface moisture which
might cause fungal decay.
The functional unit of comparison for BEES framing alternatives is 1 ft2 of load bearing wall
framing for 50 years. Preservative-treated pine wood studs, 5.08 cm x 10.16 cm (2 in x 4 in), with
a moisture content of 12 % are studied. The preservative is assumed to be Type C Chromated
Copper Arsenate (CCA), a common water-borne preservative used in the treatment of wood
products. Galvanized nails used to fasten the studs together to form the wall framing are also
studied. The flow diagram shown in Figure 3.16 shows the major elements of wood stud
production. The detailed environmental performance data for this product may be viewed by
opening the file B2013B.DBF under the File/Open menu item in the BEES software.
Raw Materials. For BEES, data were collected for the harvested trees used to produce the
lumber necessary for framing load-beaiing walls. Production of the other raw materials-steel for
nails and chromated copper arsenate for preservative—is based on data from the Ecobalance LCA
database.
Energy Requirements. The energy requirements for lumber manufacture are shown in Table
3.27. The energy is assumed to come primarily from burning wood waste. Other fuel sources,
including natural gas and petroleum, are also used.
73
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1 'I "Sill! , W' '," "'I1;,! I
Ilijf
•
Functional Unit of
Framing
Figure 3.16 Wood Framing Flow Chart
Table 3.27 Energy Requirements'for[Lumber M
Manufacturing Energy
Fuel Use" MJ/kg (Btu/lb)
Total Fossil Fuel
% Natural Gas
% Heavy Fuel Oil
% Liquid Petroleum Gas
%Hogruel
5,6(2,413)
39.8
4.1" ' """
4.1
52
"Excluding electricity
Emissions. The emissions from the lumber manufacturing process are shown in Table 3.28.
Table 3.28'Hogfuel'Emissions
,78
Emission
Amount
g/MJ Wood burned (oz/kWh)
Carbon Dioxide
Carbon Monoxide (CO)
Methane (CEL,)
Nitrogen Oxides (NOX)
Sulfur Oxides (SOX)
Volatile Organic Compounds (VOC)
Particulates
81.5 (10.35)
0.011 (6.0014)
0.008 (O.'OOI)
0.110(0.014)
0.0002 (0.000025)
0.039 (0.005)
0.708(0.09)
77 Forintek Canada Corporation, Building Materials in the Context of Sustainable Development — Raw Material
Balances, Energy Profiles and Environmental Unit Factor Estimates for Structural Wood Products, March 1993.
78 Forintek Canada Corporation, op cit.
74
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Transportation. Since sawmills are often located close to tree harvesting areas, the
transportation of lumber to the sawmill is not taken into account. However, truck transportation
of 322 km (200 mi) is assumed for the preservative. The tailpipe emissions from the track engine
and the emissions that result from the production of the fuel used in the track are taken into
account based on the Ecobalance database. Transportation of framing lumber by heavy-duty
track to the construction site is a variable of the BEES model.
Use. The density of pine at 12 % moisture content (seasoned wood) is assumed to be 449 kg/m3
(28 lb/ft3). Retention of CCA in lumber is assumed to be 6.4 kg/m3 (0.40 lb/ft3). It is assumed
that wood studs are placed 41 cm (16 in) on center and aire fastened with galvanized steel nails.
At installation, 5 % of the product is lost to waste.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code B2013, product code BO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
3.6 Roof Covering Alternatives (B3011)
3.6.1 Asphalt Shingles (B3011A)
Asphalt shingles are commonly made from fiberglass mats filled with asphalt, then coated on the
exposed side with mineral granules for both a decorative finish and a wearing layer. Asphalt
shingles are nailed over roofing felt onto sheathing.
For BEES, a roof covering of asphalt shingles with a 20 year life, roofing felt, and galvanized
nails is analyzed. The flow diagram shown in Figure 3.17 shows the elements of asphalt shingle
production. The detailed environmental performance data for: this product may be viewed by
opening the file B3011 A.DBF under the File/Open menu item in the BEES software.
Filler is assumed to be 50 % dolomite and 50 % limestone. Granules production is modeled as
rock mining and grinding. Production requirements for the asphalt shingle constituents are based
on the Ecobalance LCA database.
Seven kg (fifteen Ib) felt consists of asphalt and organic felt as listed in Table 3.30. The organic
felt is assumed to consist of 50 % recycled cardboard and 50 % wood chips. The production of
these materials, and the asphalt, is based on the Ecobalance LCA database.
Energy Requirements. The energy requirement for asphalt shingle production is assumed to be
75
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Figure 3.17 Asphalt Shingles Flow Chart
33 MJ/m2 of natural gas (2,843 Btu/ft2) of shingles.
Raw Materials. Asphalt shingles are composed of the materials listed in Table 3.29.
Table 3.29 Asphalt Shingle Constituents
Asphalt Shingle Constituents Physical Weight
Asphalt
filler"'' "' '
Fiberglass
Granules
1.9 kg/m2 (40 Ib/square)
4.2 kg/in2 (86 Ib/square)
0.2 kg/m2 (4 Ib/square)
3.7 kg/ m2 (75 Ib/square)
Table 3.30 Seven Kg (15 Ib) Roofing Felt Constituents
7kg(15lb)
Felt Constituents Physical Weight
Asphalt
Organic Felt
Total:
0.5 kg/m2 (9.6 Ib/square)
0.3 kg/ m2 (5.4 Ib/square)
0.8 kg/ m2 (15 Ib/square)
Emissions. Emissions associated with manufacturing asphalt shingles and roofing felt are taken
Into account based on AP-42 data for asphalt shingle and saturatecl felt processing.
Transportation. Transport of the asphalt shingle raw materials is taken into account. The
distance transported is assumed to be 402 km (250 mi) for all of the components. Asphalt is
assumed to be transported by truck, train, and pipeline in equal proportions. Dolomite, limestone,
and granules are assumed to be transported by truck and train in equal proportions. Fiberglass is
assumed to be transported by truck.
it.!!
76
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Transport of the raw materials for roofing felt is also taken into account. The distance
transported is assumed to be 402 km (250 mi) for all of the components. Asphalt is assumed to
be transported by truck, train, and pipeline in equal proportions, while the cardboard and wood
chips are assumed to be transported by truck. :
Transport of the shingles, roofing felt, and nails to the building site is a variable of the BEES
system.
Use. It is important to consider solar reflectivity differences among roof coverings of different
materials and colors when assessing the environmental and economic performance of roof
covering alternatives. "Cool" roofs reflect and emit solar radiation well, and thus stay cooler in
the sun than less reflective, less emissive materials. The cool temperature results in building-scale
cooling energy savings ranging from 2 % to 60 %.79 A much less significant rise in building
heating energy costs also occurs. BEES accounts for solar reflectivity performance in computing
energy-related LCA inventory flows and building energy costs over the 50 year use stage for roof
covering products.
For roof coverings, thermal performance differences are separately assessed for 16 U.S. cities
spread across a range of Sunbelt climate and fuel cost zones. When selecting roof covering
alternatives for use in Sunbelt climates,80 the BEES user chooses 1) the roof covering material and
color, 2) the U.S. Sunbelt climate city closest to the building location, 3) the building type (new
or existing), 4) its heating and cooling system (electric air-source heat pump or gas
furnace/central air conditioning heating and cooling systems), and 5) its duct placement
(uninsulated attic ducts or ducts in the conditioned space), so that thermal performance
differences may be customized to these important contributors to building energy use. Energy use
data provided to the National Institute of Standards and Technology by Lawrence Berkeley
National Laboratory (and which LBL developed for the U.S. EPA Energy Star Roof Products
program), tailored to these five parameters, are used to estimate 50 year heating and cooling
requirements per functional unit of roof covering.81 BEES environmental performance results
account for the energy-related inventory flows resulting from these energy requirements (stored in
USEFLOWS.DBF), and BEES economic performance results account for the present value cost
resulting from these energy requirements (stored in USEECON.DBF).
Asphalt shingle and roofing felt installation is assumed to require 47 nails/ m2 (440 nails/square).
Installation waste from scrap is estimated at 5 % of the installed weight. At 20 years, new shingles
are installed over the existing shingles. At 40 years, bom layers of roof covering are removed
before installing replacement shingles. '
79 Memorandum from Sarah Bretz/Lawrence Berkeley National Laboratory to Barbara Lippiatt/National
Institute of Standards and Technology, 12/18/98.
80 In cold climates, the amount of roof insulation is more important to thermal performance than the color of the
roof covering. ;
81 LBL data were developed for BEES by LBL's Sarah Bretz, based on Konopacki and Akbari, Simulated
Impact of Roof 'Surface Solar Absorptance, Attic, and Duct Insulation on Cooling and Heating Energy Use in
Single-Family New Residential Buildings, LBNL-41834, Lawrence Berkeley National Laboratory, Berkeley, CA,
1998, and on Parker et al., "Measured and Simulated Performance of Reflective Roofing Systems hi Residential
ASHRAE Transactions, SF-98-6-2, Vol. 104,1998, p. 1. :
77
-------
"Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCQSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code B3011, product code AO. Life-cycle cost data include first cost data (purchase and
|nstajlation costs} and future cost data (cost and frequen^^
lh I J; Ufe ' ' -"'Ind'data are'available, of operation, maintenance, and repair)™ "Operational energy costs for roof
coverings in US. Sunbelt climates (discussed above under "Use") are found in the file
USEECON.DBF. First cost data are collected from the R.S. Means publication, 2000 Building
Construction Cost Data, and other future cost data are based on data published by Whitestone
Research in The Whitestone Building Maintenance and Repair Cost Reference 1999,
supplemented by industry interviews.
3.6.2 Clay Tile (B3011B)
Slay tiles are made by shaping and firing clay, the most commonly used clay tile is the red
Spanish "tile" For the SEES system, a roof covering of 70 year red Spanish clay tiles, roofing felt,
and nails is studied. Due to the weight of the tile and its relatively long useful life, 14 kg (30 Ib)
:;:felf 'as4 ^ojjjgier' rails' are" usecL The flow diagram shown in Figure 3.18 shows the elements of clay
tile production. The detailed environmental performance data for this product may be viewed by
opening the file B301 1B.DBF under the File/Open menu item in the BEES software.
Materials. The weight of the clay tile studied is 381 kg (840 Ib) per square, requiring 171
pieces of tilel Production of the clay is based on the Ecobalance LCA database.
"|piirte,?!n kg "(SO'lti)' felt consists of asphalt and organic felt as listed in Table 33L The organic
felt is assumed to consist of 50 % recycled cardboard and 50 % wood chips. The production of
these materials, and the asphalt, is based on the Ecobalance LCA database.
Table 3.31 Fourteen Kg (30 Ib) Roofing Felt Constituents
14 kg (30 Ib) ' "
Felt Constituents Physical Weight
Asphalt
Organic Felt
Total:
0.9 kg/m2 (19.2 Ib/square)
0.5 kg/m2 (10.8 Ib/square)
1.4kg/m2(301b/square)
78
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Clay Tiles
Functional Unit
of Clay Tile Roofing
Figure 3.18 Clay Tile Flow Chart
Energy Requirements. The energy required to fire clay tile is 6.3 MJ per kg (2,708 Btu per Ib) of
clay tile. The fuel type is natural gas.
Emissions. Emissions associated with natural gas combustion are based on AP-42 emission
factors.
Transportation. Transport of the cky raw material is taken into account. The distance
transported is assumed to be 402 km (250 mi) for the clay by train and truck. Transport of the
raw materials for roofing felt is also taken into account. The distance transported is assumed to
be 402 km (250 mi) for all of the components. Asphalt is assumed to be transported by truck,
train, and pipeline in equal proportions, while the cardboard and wood chips are assumed to be
transported by truck. Transport of the tiles to the building site is a variable of the BEES model.
Use. It is important to consider solar reflectivity differences among roof coverings of different
materials and colors when assessing the environmental and economic performance of roof
covering alternatives. "Cool" roofs reflect and emit solar radiation well, and thus stay cooler in
the sun than less reflective, less emissive materials. The cool temperature results in building-scale
cooling energy savings ranging from 2 % to 60 %.82 A much less significant rise in building
heating energy costs also occurs. BEES accounts for solar refle'ctivity performance in computing
energy-related LCA inventory flows and building energy costs over the 50 year use stage for roof
covering products. '•
82 Memorandum from Sarah Bretz/Lawrence Berkeley National Laboratory to Barbara Lippiatt/National
Institute of Standards and Technology, 12/18/98. '
79
-------
ill 1W 'r ,1 ,; "
Illllll II
For roof coverings, thermal performance differences are separately assessed for 16 U.S. cities
spread across a range of Sunbelt climate and fuel cost zones. When selecting roof covering
.glte.rnatJYesfor use m Sunbelt climates,83 the BEES user chooses 1) the roof covering material
and color, 2) the U.S. Sunbelt climate city closest to the building location, 3) the building type
(new or existing), 4) its heating and cooling system (electric air-source heat pump or gas
fUrnace/central air conditioning heating and cooling systems), and 5) its duct placement
(uninsulated attic ducts or ducts in the conditioned space), so that thermal performance
differences may be customized to these important contributors to building energy use. Energy use
data provided to the National Institute of Standards and Technology by Lawrence Berkeley
National Laboratory (and which LBL developed for the U.S. EPA Energy Star Roof Products
pro'grain), tailored to these five parameters, are used to estimate 50 year heating and cooling
• requirementsjper runctibnalumt Of roof covering?4 BEES environmental performance results
jfbe0\j£iitj^ flows resulting from these energy requirements (stored in
USEFLpWsrDBF), arid BEES ecorioniic performance results account for the present value cost
resulting from these energy requirements (stored in USEECON.3DBF).
-;, i'l-i, •:, •*;•(•>••. :!iit^ rtV I III :'"' it: I : ,•:<' :•••> in •'• l^.i: ( M (,,': ^ ', - I 'I-....: I ••>•," ; i),: ;. i- "J
lay tile roofing is assumed to require two layers of 14 kg (30 Ib) roofing felt, 13 galvanized
I '•IlilE'" • li'llii1!
•, I ill1 .:;"!
r (12p/square) for underlayment, and 37 copper nails/m (342/square) for the tile (2 copper
nails/file). Installation waste from scrap is estimated at 5 % of the installed weight. One-fourth of
lie tiles are replaced after 20 years, and another one-fourth at 40 years. All tiles are replaced at 70
The detailed life-cycle cost data for this product may be viewed by opening the file
BF under the File/Open menu item in me BEES software. Its costs are listed under
BEES code "B3011, product code BO. Life-cycle cost 'data mclucle first cost data (purchase arid
installation"costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). Operational energy costs for roof
coverings "in tl"& Sunbelt climates (discussed above under "Use") are found in the file
USEECON.DBF. First cost data are collected from the R.S. Means publication, 2000 Building
Construction Cost Data, and other future cost data are based on data published by Whitestone
II I "I i'i'IlLiiMh iWnlli I »'" i .'.'V,, j'i '!,„ ', ". i, ,,;'i 'i,,' run. j, ,,i „; i j,,, -i; '':,,,':: HI! .,!< jTilii* ' i,i:'iiiii t*r -.Mjhi ;'"„', ::";,:/„ ",, ,i ,.i, „ ' .: MI 11 ,;;u,,:1
Research in The Whitestone Building Maintenance and Repair Cost Reference 1999,
supplemented by industry interviews.
83 In cold climates, the amount of roof insulation is more important to thermal performance than the color of the
roof covering.
M LBL da^ were developed for BEES by LBL's Sarah Bretz, based on Konopacki and Akbari, Simulated
Impact of Roof Surface Solar Absorptance, Attic, and Duct Insulation on Cooling and Heating Energy Use in
Single-Family New Residential Buildings, LBNL-41834, Lawrence Berkeley National Laboratory, Berkeley, CA,
1998, and on Parker et al., "Measured and Simulated Performance of Reflective Roofing Systems in Residential
ASHRAE Transactions, SF-98-6-2, Vol. 104, 1998, p. 1.
80
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3.6.3 Fiber Cement Shingles (B3011C)
In the past, fiber cement shingles were manufactured using asbestos fibers. Now asbestos fibers
have been replaced with cellulose fibers. For the BEES study, a 45 year fiber cement shingle
consisting of cement, sand, and cellulose fibers is studied. Roofing felt and galvanized nails are
used for installation. The flow diagram shown in Figure 3.19 shows the elements of fiber cement
shingle production. The detailed environmental performance data for this product may be viewed
by opening the file B3011C.DBF under the File/Open menu item in the BEES software.
Raw Materials. Fiber cement shingles are composed of the materials listed in Table 3.32. The
filler is sand, and the organic fiber is wood chips. The weight of fiber cement shingles is assumed
to be 16 kg/m2 (325 Ib/square), based on 36 cm x 76 cm x 0.4 cm (14 in x 30 in x 5/32 in) size
shingles.
Functional Unit of
F:iber Cement Shingles
Figure 3.19 Fiber Cement Shingles Flow Chart
Table 3.32 Fiber Cement Shingle Constituents
Fiber Cement Shingle Physical Weight
Constituents (%)
Portland Cement
Filler
Organic Fiber
90
5
5
Portland cement production requirements are identical to those noted above for a stucco exterior
wall finish. Fourteen kg (30 Ib) roofing felt is modeled as noted above for clay tile roofing.
Production requirements for the raw materials is based on the Ecobalance LCA database.
81
-------
ilii'f
:,:!!ll!illi. . i Ml' .'•:.
Ii •,- ..>'•... • •„ •• .: i i i
iliBi. ,'i "Hi nil1 .iii'iifti '.ail!," • r-: !:,:; .'tin •" (I til '"i"1"!1 • • , i "i.;,,," wn'i y,i-,k: < i1 I I
Use. It is important to consider solar reflectivity differences among roof coverings of different
materials and colors when assessing me environmental and economic performance of roof
covering alternatives. "Cool" roofs reflect and emit solar radiation well, and thus stay cooler in
the sun than less reflective, less emissive materials. The cool temperature results in building-scale
cooling energy savings ranging from 2 % to 60 %.85 A much less significant rise in building
heating energy costs also occurs. BEES accounts for solar reflectivity performance in computing
energy-related LCA inventory flows and building energy costs over the 50 year use stage for roof
covering products.
For roof coverings, thermal performance differences are separately assessed for 16 U.S. cities
spread across a range of Sunbelt climate and fuel cost zones. When selecting roof covering
alternatives for use in Sunbelt climates,86 the BEES user chooses 1) the roof covering material
and color, 2) the U.S. Sunbelt climate city closest to the building location, 3) the building type
(new or existing), 4) its heating and cooling system (electric air-source heat pump or gas
furnace/central air conditioning heating and cooling systems), and 5) its duct placement
ilp, •„[!>, "" . 1- III '" ilfllll!!:- IHJ|:"..( .l-iV!"" "'Mi:,: ° ... I V, -f • '," :tf " <: T »'• r ™, !, -,. ; ...I i .; C : , ,,l,i,
(uninsulated attic ducts or ducts in the conditioned space), so that thermal performance
differences may be customized to these important contributors to building energy use. Energy use
data provided to the National Institute of Standards and Technology by Lawrence Berkeley
National Laboratory (and which LBL developed for the U.S. EPA Energy Star Roof Products
program), tailored to these five parameters, are used to estimate 50 year heating and cooling
requirements per functional unit of roof covering.87 BEES environmental performance results
jtCQpujit.fQrttie_energy-reIated inventory flows resulting from these energy requirements (stored in
USEFLOWS.DBF), and BEES economic performance results account for the present value cost
resulting from these energy requirements (stored in USEECON.DBF).
*5 Memorandum from Sarah Bretz/Lawrence Berkeley National Laboratory to Barbara Lippiatt/National
Institute of Standards and Technology, 12/18/98.
86 In cold climates, the amount of roof insulation is more important to thermal performance than the color of the
roof covering.
87 LBL data were developed for BEES by LBL's Sarah Bretz, based on Konopacki and Akbari, Simulated
•Impact of Roof Surface Solar Absorptance, Attic, and Duct Insulation on Cooling and Heating Energy Use in
Single-Family New Residential Buildings, LBNL-41834, Lawrence Berkeley National Laboratory, Berkeley, CA,
1998, and on Parker et al., "Measured and Simulated Performance of Reflective Roofing Systems in Residential
Transactions, SF-9S-&-2, Vof.'l64, 1998, p. 1.
82
-------
Fiber cement shingle roofing requires one layer of 14 kg (30 Ib) felt underlayment, 13 nails/m2
(120 nails/square) for the underlayment, and 32 nails/m2 (300 nails/square) for the shingles.
Installation waste from scrap is estimated at 5 % of the installed weight. Fiber cement roofing is
assumed to have a useful life of 45 years.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code B3011, product code CO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
arid data are available, of operation, maintenance, and repair).'Operational energy costs for roof
coverings in U.S. Sunbelt climates (discussed above under "Use") are found in the file
USEECON.DBF. First cost data are collected from the R.S. Means publication, 2000 Building
Construction Cost Data, and other future cost data are based,on data published by Whitestone
Research in The Whitestone Building Maintenance and- Repair Cost Reference 1999,
supplemented by industry interviews.
3.7 Interior Finishes (C3012)
3.7.1 Paints - General Information
Conventional paints are generally classified into two basic categories: water-based (in which the
solvent is water) and oil-based (in which the solvent is an organic liquid, usually derived from
petrochemicals). Oil-based paints are sometimes referred to as solvent-based. Paints essentially
consist of a resin or binder, pigments, and a carrier in which these are dissolved or suspended.
Once the paint is applied to a surface, the carrier evaporates, leaving behind a solid coating. In
oil-based paints the carrier is a solvent consisting of volatile organic compounds (VOCs), which
can adversely affect indoor air quality and the environment. As a result, government regulations
and consumer demand are forcing continuing changes in paint formulations. These changes have
led to formulations containing more paint solids and less solvent, and a shift away from oil-based
paints to waterborne or latex paints.
Paint manufacture essentially consists of combining the ingredients, less some of the solvent, in a
steel mixing vessel. In some cases the mixing is followed by a; grinding operation to break up the
dry ingredients, which tend to clump during mixing. Finally, additional solvents or other liquids
are added to achieve final viscosity, and supplemental tinting is added. The paint is then strained,
put into cans, and packaged for shipping.
Because they do not use solvents as the primary carrier, latex paints emit far fewer volatile
organic compounds (VOCs) upon application. They also do not require solvents for cleaning of
the tools and equipment. Water with a coalescing agent is the carrier for latex paints. The
coalescing agent is typically a glycol or glycol ether. The binder is synthetic latex made from
polyvinyl acetate and/or acrylic polymers and copolymers. Titanium dioxide is the primary
pigment used to impart hiding properties in white or light-colored paints. A range of pigment
extenders may be added. Other additives include surfactants, defoamers, preservatives, and
83
-------
lull
I1
'""i! ! ; i ;'
;! "si- ' ' 1
fungicides.
BEES considers two latex-based paint alternatives, virgin latex paint and latex paint with a 35 %
recycled content. The two alternatives are applied the same way. The surface to be painted is first
primed an<3 men painted with two coats of paint. One coat of paint is then applied every 4 years!
The characteristics of both the paint and the primer are displayed in Table 3.33.
Ij? iff lifciii iii.ii I.; iw:,[; Table 3.33 Characteristics of BEES Paints and Primer
' *: ':'' »• ^Characteristic '.
Primer Paint (recycled or virgin)
rate of the coat m2/L
(fWgal)
Density .of product kg/L (Ib/gal)
7.4 (300)
1.26(10.5)
8.6(350)
1.28(10.7)
:3/7.2 Virgin Latex Interior Paint (C3012A)
Major virgin latex paint constituents are resins (binder), titanium dioxide (pigment), limestone
(extender), and water (thinner), which are mixed together until they form an emulsion. Figure
3.20 displays the system under study for virgin latex paint.
Functional Unit of
Virgin Latex Interior Paint
Figure 3.20 Virgin Latex Interior Paint Flow Chart
Maw Materials. The average composition of the virgin latex paint/primer system modeled in
BEES is listed in Table 3.34.
84
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Table 3.34 Virgin Latex Paint and Primer Constituents
Constituent
Resin
Titanium dioxide
Limestone
Water
Paint
(Weight %)
25 •
12.5
12.5
50
Primer
(Weight %)
25
7.5
7.5
60
Table 3.35 displays the market shares for the resins used for interior latex paint and primer.
Table 3.35 Market Shares of Resins
Resin type
Market share ( %)
Vinyl Acrylic
Polyvinyl Acetate
Styrene Acrylic
40
40
20
Table 3.36 shows the components of the three types of resin as modeled in BEES. The production
of the monomers used in the resins is based on-the Ecobalance LCA database.
Table 3.36 Components of Paint Resins
Resin Type
Components
Vinyl Acrylic
Polyvinyl Acetate
Styrene Acrylic
Vinyl acetate (50 %)
Butyl acrylate (50 %)
Vinyl acetate (100 %)
Styrene (50 %)
Butyl acrylate (50 %)
Emissions. Emissions associated with paint manufacturing, such as particulates to the air, are
based on AP-42 emission factors.
Transportation. Truck transportation of raw materials to the paint manufacturing site is assumed
to average 402 km (250 mi) for titanium dioxide and limestone, and 80 km (50 mi) for the resins.
Use. Refer to Section 2.1.3, Impact Assessment, for a discussion of indoor air quality scoring for
paints.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code C3012, product code AO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). .First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
85
-------
ill!
i i
i (nil
3.7.3 Recycled Latex Interior Paint (C3012B)
Figure 3.21 displays the BEES flow chart for recycled latex paint.
1
in
.•
Truck Transport
v • •;'• . ::i .; >*
ii. •• |L ,: " " ; i;!!,;1 • ."• ; , ',,
^ Functional Unit of ,
* Recycled Latex Interior Paint
';'. t :" ''', "' ,'!': •." i-, •'" :"'':' '";"' '.'•..'; ''
Recycled Latex . Truck transpor n,-«». *«„ ' - Truck Transpor
ntertor Paint Mfg *~ (Raw Mail's) Pnmer mg + (Raw Mail's)
•i JUS1;1":,,'.1 .,1 kBIiiii . • •!, •" * • | f
Transport
of recycled
paint
; -i ;
j L
Virgin Latex
Interior Paint Mfg
•,' •' , ! " ; ; ,'j;,: ,„
1 i j ;n i •••'•• ' ' . HI.. . " *
^_ Truck Transpor _ . ... ^'^"'ilS Limestone
*• (Raw Mall's) Resin Mfg Oxide Mfg Quarrying
,' , : ;;x "::'; "ij: •,:'
Titanium
Resin Mfg Oxide Mfg
Limestone
Quarrying
!" ' i : ' ' ' ,'
• • . .. • • • •'
Figure 3.21 Recycled Latex Interior Paint Flow Chart
, ' '", \
„, ,, , , , , , , ,„ ,j , , ,
i j ' i
Raw Materials. The latex paint under study has a 65 % recycled content, or a 35 % content of
vjrgin materials. The recycled content of the paint consists of leftover paint that is collected. After
being pre-sorted at the collection site, recycled paints are sorted again at the "re-manufacturing"
site. It is assumed that 10 % of the collected paint imported to the "re-manufacturing" site must
be discarded (paint contaminated with texture material such as sand). The recycled paint is
: ejiyirorimenfally "free", but its transportation to the paint manufacturing site is taken into account.
The virgin materials in trie recycled paint consist of either virgin paint ingredients (resin, titanium
dioxide, and limestone) or virgin paint as a whole.
86
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Transportation. Transport of collected paint from the collection point to the re-manufacturing
site is assumed to average 80 km (50 mi) by truck.
Emissions. Emissions associated with paint manufacturing, such as particulates to the air, are
based on AP-42 emission factors. :
Use. Refer to Section 2.1.3, Impact Assessment, for a discussion of indoor air quality scoring for
paints.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code C3012, product code BO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
3.8 Floor Covering Alternatives (C3020)
3.8.1 Ceramic Tile with Recycled Windshield Glass (C3020A)
Ceramic tile flooring consists of clay, or a mixture of clay and other ceramic materials, which is
baked in a kiln to a permanent hardness. To improve environmental performance, recycled
windshield glass can be added to the ceramic mix. For the BEES system, 50 year ceramic tile with
75 % recycled windshield glass content, installed using a latex-cement mortar, is studied. The
flow diagram shown in Figure 3.22 shows the elements of ceramic tile with recycled glass
production. The detailed environmental performance data for this product may be viewed by
opening the file C3020A.DBF under the File/Open menu item in the BEES software.
Raw Materials. For a 15 cm x 15 cm x 1.3 cm (6 in x 6 in x Yz in) ceramic tile with 75 % recycled
glass content, clay and glass are found in the quantities listed in Table 3.37.
Table 3.37 Ceramic Tile with Recycled Glass Constituents
Ceramic Tile w/ Recycled
Glass Constituents
Recycled Glass
Clay
Total:
Physical Weight
475.5 g (17 oz)
156.9g(6oz)
632.4 g (23 oz)
87
-------
|!il!1!!1; j fi i. ', ;-
1 II'iff I '.Hll11'! .ill ''I,*,,
HI Eijll'l ' !'
IB, I !
iiiJii..). :'" 11
Ceramic Tile w/ Recycled Glass
.!••] !'••
Figure 3.22 Ceramic Tile with Recycled Glass Flow Chart
production requirements for clay are based on the Ecobalance LCA database. The recycled
windshield glass material is environmentally-"free." Burdens associated with glass production
bhould be allocated tq the product with the first use of the glass (vehicle windshields). The
transportation of the glass to the tile facility and the processing of the glass are taken into
account.,. i r_. :; , i i i . __„ i ... , „ ,; ... i , ,;r '' ,
,i.: ' ifi'in' : wii'l ' ' i;|l|ili iiii "" ' , ' "i1" ', ' ii ' ' ,'»'""1',,»Ji:' 'ii11'1. ' '"•'' Ml.' „•» " ' ' ''• :,. i'1 ' ,,','i'1'" ',.,!!!',' ", ii Ii 'iliiii',', " :' i /Kii'il'!''!11:! '1|:',"'i'!' ' III
The production of mortar (1 part portland cement, 5 parts sand) and styrene-butadiene are based
on the Scqbajiance LCA databas,e,,F,, ^ j; , ir |P| , ^ ;, ,
Energy Requirements. The energy requirements for the drying and firing processes of ceramic
tile production are listed in Table 3.38.
i n inn i i n IHIII - - 'i' . '"i'', 11 •.,:.. '"i . i ii nh pi 11
Table 3.38 Energy Requirements for Ceramic Tile with Recycled Glass Manufacturing
\ ;:-:•• I;', ti; ",; , . ""'; ,: ,> i,;;;;:,,; •.?: :•";: :,;:' -;. Manufacturing
'_•'• • :' Fuel Use Energy
"';.;•:-•' „ :: ' .; . "":;:: :,;:; / Total Fossil Fuel „,, 449MJ/kg(l,8pl Btu/lbJ \
iii-h.1!'. I:, ' "'" ''41:- 'i:!::l • % Natural Gas* 71.9 ' " "|
% Fuel Oil 7.8
; |l;": .:' ::: „' : - ,/: "'":1 .' • % Wood 108
iliii . i | i. '• "i" ... .. ': i ill ir i..'l! . " ^-rH—:",:, ;: ::::,—^ ;: • :„, '—— ;: . "•: :•": •-^-;..' ' :" .: " ' . •; ::.
;"™I;I' ; •'• | • *_.. ! ' .. '"r ".f;1 . * Includes Propane
,1 !'!, - I , I" ' It.1,1 ;„ , i'1, „- 'ini I. ,. HI ' •; ' t 111 II II '
Emissions. Ernissiqns associated with fuel combustion for tile manufectming are based on AP-42
a^n'it1'' ,'. |rassion'fectqrsr ... ,III'L. '; /] ' "'' i , ,..,.,...! „,] ,"
Use. Installation of ceramic tile is assumed to require a layer of latex-mortar approximately 1.3
cm (1/2 in) tiuck. The relatively small amount of latex-mortar between tiles is not included.
m'il'T i': i.i II 'I'.:: i! in i i n n il
::-„ •; ; -,", gg
.nil! Ji I ."ki.l "' illiM I II III II I
-------
Ceramic tile with recycled glass is assumed to have a useful life :of 50 years.
Refer to section 2.1.3 for indoor air performance assumptions for this product.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code C3020, product code AO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair).: First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
3.8.2 Linoleum Flooring (C30202) ;
Linoleum is a resilient, organic-based floor covering consisting of a backing covered with a thick
wearing surface. For the BEES system, a 2.5 mm (0.098 in); sheet linoleum, manufactured in
Europe, and with a jute backing and an acrylic lacquer finish coat is studied. A styrene-butadiene
adhesive is included for installation. The flow diagram shown in Figure 3.23 shows the elements
of linoleum flooring production. The detailed environmental performance data for this product
may be viewed by opening the file C3020B.DBF under the File/Open menu item in the BEES
software.
Raw Materials. Table 3.39 lists the constituents of 2.5 mm (98 mil) linoleum and their
proportions.
Table 3.39 Linoleum Constituents
Constituent
linseed oil
pine rosin
limestone
wood flour
cork flour
pigment
backing (jute)
acrylic lacquer
Total:
Physical Weight ( %)*
23.3
7.8
17.7
30.5
5.0
4.4
10.9
0.35
100.0
Physical Weight
670 g/m2 (2.2 oz/ft2)
224 g/m2 (0.7oz/ft2)
509g/m2(1.7oz/ft2)
877 g/m2 (2.9 oz/ft2)
144 g/m2 (0.5 oz/ft2)
127 g/m2 (0.4 oz/ft2)
313 g/m2 (1.0 oz/ft2)
10 g/m2 (0.03 oz/ft2)
2874 g/m2 (9.4 oz/ft2)
Jonsson Asa, Anne-Marie Tillman, and Torbjorn Svensson, Life-Cycle Assessment of Flooring Materials, Chalmers
University of Technology, Sweden, 1995.
89
-------
IXllll
IHli ,
Figure 3.23 Linoleum Flow Chart
The cultivation of linseed is based on a United States agricultural model which estimates soil
erosion and fertilizer run-off,88 with the following inputs:89
• Fertilizer: 35 kg nitrogen fertilizer per10,000 m2 (31 Ib/acre), 17 kg phosphorous fertilizer
per hectare (15 Ib/acre), and 14 kg potassium fertilizer per 10,000 m2 (12 Ib/acre)
• Pesticides: 0.5 kg active compounds per hectare (0.4 Ib/acre), with 20 % lost to air
* Diesel farm tractor: 0.65 MJ per kg (279 Btu per Ib) linseed
. •• Linseed yield: 600 kg/10,000m2 (536 Ib/acre)
The production of the fertilizers and pesticides is based on the Ecobalance LCA database. The
gu|tiyation of pine trees for pine rosin is based on Ecobalance LCA data for cultivated forestry,
jlath mventory Hows allocated | between pine rosin and its coproduct, tuipentine. The production
of limestone is based on Ecobalance data; fbr open pit limestone quarrying and processing. Wood
Jtpur is c sawdust produced as a coproduct of wood processing. Its production is based on the
Ecoba|ance LCA database.,, Cork flour is a coproduct of wine cork production. Cork tree
cultivation is not included but the processing of the cork is included as shown below. Heavy
metal pigments are used in linoleum production. Production of these pigments are modeled based
on the production of titanium dioxide pigment. Jute used in linoleum manufacturing is mostly
grown in India and Bangladesh. Its production is based on the Ecobalance LCA database. The
production of acrylic lacquer is based on the Ecobalance LCA database.
.- !l
Ecobalance, She|h,an, J. pj aj.. Life Cycle Inventory of Biodiesel and Petroleum Diesel for Use in an Urban Bus,
NREL/SR-580-24089, prepared for USD A and IIS DoE, May 1998.
"Potting Jose and Kornelis Blok, Life-cycle Assessment of Four Types of Floor Covering, Utrecht University,
The Netherlands, 1994.
90
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Energy Requirements. Energy requirements for linseed oil production include fuel oil and steam,
and are allocated on a mass basis between linseed oil (34 %) and linseed cake (66 %). Allocation
is necessary because linseed cake is a co-product of linseed oil production whose energy
requirements should not be included in the BEES data. :
Cork Flour production involves the energy requirements as listed in Table 3.40.
Table 3.40 Energy Requirements for Cork Flour Production
Cork Product Electricity Use '
Cork Bark
Ground Cork
0.06 MJ/kg (26 Btu/lb)
1.62MJ/kg(696Btu/lb)
Linoleum production involves the energy requirements as listed in Table 3.41.
Table 3.41 Energy Requirements for Linoleum Manufacturing
Fuel Use Manufacturing Energy
Electricity
Natural Gas
2.3 MJ/kg (989 Btu/lb)
5.2 MJ/kg (2,235 Btu/lb)
Emissions. Tractor emissions for linseed cultivation are based on the Ecobalance LCA database.
The emissions associated with linseed oil production are allocated on a mass basis between oil (34
%) and cake (66 %).
Since most linoleum manufacturing takes place in Europe., it is assumed to be a European product
in the BEES model. European linoleum manufacturing results in the following air emissions in
addition to those from the energy use:
• Volatile Organic Compounds: 1.6 g/kg (0.025 oz/lb) :
• Solvents: 0.94 g/kg (0.015 oz/lb)
• Particulates: 0.23 g/kg (0.004 oz/lb)
Transportation. Transport of linoleum raw materials from point of origin to a European
manufacturing location is shown in Table 3.42.90 .
Table 3.42 Linoleum Raw Materials Transportation
Raw Material
Distance
Mode of Transport
linseed oil
pine rosin
limestone
wood flour
cork flour
4,350 km (2,703 mil)
1,500 km (932 mi)
2,000 km (1,243 mi)
800 km (497 mi)
600 km (373 mi)
2,000 km (1,243 mi)
Ocean Freighter
Train
Ocean Freighter
Train
Train
Ocean Freighter
90 Life-Cycle Assessment of Flooring Materials, Jonsson Asa, Anne-Marie Tillman, & Torbjorn Svensson,
Chalmers University of Technology, Sweden, 1995. ;
91
-------
pigment
backing (jute)
acrylic lacquer
500 km (311 mi)
10,000 km (6,214 mi)
500 km"(311 mi)
Diesel Truck
Ocean Freighter
Diesel Truck
Transport of the finished product from Europe to the United States is included. Transport of the
finished product from the point of U.S. entry to the building site is a variable' of the BEES model.
Use. The installation of Imoleum requires a styrene-butadiene adhesive. Linoleum flooring has a
useful life of 18 years.
r, :l : . :;KJ,:''7" • •;• ,.,':• • •••• '.• \
Refer to section 2.1.3 for indoor air performance assumptions for this product.
Hill I II I III II :: ,,11 ','! ":",,,, i, "' 'J< \ 1''/i'"!1''' '"' ,"",!! II III 11 || I , ij;,, ' „' l'i' ll
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code C3020, product code BO. Life-cycle cost data include first cost data (purchase and
Installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). First cost data are collected from
ifce R.S. Means publication, 2000 Building Construction Cost_ Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
•;i ' MM":!!-,
lili i i mi i i i in i i ifi!'! '•..• '••., ; tpl':x'
3.8.3 Vinyl Composition Tile (C3020C)
Vinyl composition tile is a resilient floor covering. Relative to the other types of vinyl flooring
(vinyl sheet flooring and vinyl tile), vinyl composition tile contains a high proportion of inorganic
filler. For the BEES study, vinyl composition tile is modeled with a composition of limestone,
plasticizer, and a copolymer of vinyl chloride-vinyl acetate. A layer of styrene-butadiene adhesive
is used during installation. Figure 3.24 shows the elements of vinyl composition tile production.
The detailed environmental performance data for this product may be viewed by opening the file
b302bC.bBF under the Fne/ppen menu item in the BEES sofbyare.
• •"•'••'•'•' i : • • • j
law Materials.Table 3.43"fists ^the constituents of 30 cm x 30 cm x 0.3 cm (12 inx 12 in x 1/8
in) yinyl composition tile and their proportions. A finish coat of acrylic latex is applied to the vinyl
SSmposition tile at manufacture. The thickness of the finish coat is assumed to be 0.025 mm
{0.98 mils)."The production of these raw materials, and the styrene-butadiene adhesive, is based
on the Ecobalance LCA database.
92
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Vinyl Composition Tile
Truck Functional Unit of
Transport Vinyl Comp Tile
End-of-Life . ' :
t ' • . •
i I1,!1 i '!! ,! ,/: '' ,' ' ' • I" I'll < 1 . Tf "i','1 ' ,, "IF1 :!ill!1' :W " ': J1' '
BSe «-
Producti°n Production
T
1
ne Butadiene
:tion Production
Limestone Fuel Oil ^etete' Electricity *=^ Plasticizer PVC
Production Production Production PmducUon production Production Production
, ' L
Electricity Elhylene Acetic acid - Oxygen Electricity Electricity Fuel Oil Elect
Production Production Production Production Production Production Production Produ
J L ' . • . !-
Electricity Electricity
Production Production
Figure 3.24 Vinyl Composition Tile Flow Chart
Table 3.43 Vinyl Composition Tile Constituents
Constituent
Physical Weight ( %)
Limestone
Vinyl resins:
10 % vinyl acetate / 90 % vinyl chloride
Plasticizer: bis(2-ethylhexyl) phthalate
84
12
4
Energy Requirements. Energy requirements for the manufacturing process (mixing,
folding/calendaring, finish coating, and die cutting) are listed in Table 3.44.
Table 3.44 Energy Requirements for Vinyl Composition Tile Manufacturing
Manufacturing
Fuel Use Energy
Electricity
Natural Gas
1.36MJ/kg(585Btu/lb)
0.85 MJ / kg (365 Btu/lb)
Emissions. Emissions associated with the manufacturing process arise from the combustion of
fuel oil and are based on AP-42 emission factors.
Use. Installing vinyl composition tile requires a layer of styrene-butadiene adhesive 0.0025 mm
93
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I '.- ! 1
liiiiijjjjjjjjjjjjjjjjjjjjiiijijj|'l|iilriii:jii ¥ ,|ii in1]11:];
I
!*f :,i" •''i ;;.!!'{
I iiil'i:
mt"t
ilniiii" ; i.
IB It 'I
ill!11]!
, fKif'si.TiipJWiBirairi^ftt.fl.
ips"!! fS y;V" .,'!!»,'I,:', '-it i1^
l"!":,:.:.<;.Jii;':l' iW:rl .JSTk', , ",i ',!':! ill"
'1 "IfcMi,
i.WF
' 'HiiiHlnii! W^
(0.10 mils) thick. The life of the flooring is assumed to be 18 years.
Refer to section 2.1.3 for indoor air performance assumptions for this product.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
B_EgS code C3MP, product code CO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
3.8.4 Composite Marble Tile (C3020D)
Composite marble tile is a type of composition flooring. It is a mixture of polyester resin and
;jj£ ,,,;,',[.;,I,,:;, , ~ • (ffia|rix, nljerthaf is,colored for,marble effbct and poured" into a mold. The mold is then vibrated to
release air and level the matrix. After curing and shrinkage the part is removed from the mold,
trimmed, and polished if necessary. For the BEES system, a 30 cm x 30 cm x 0.95 cm (12 in x 12
in x 3/8 in) tile, installed using a latex-cement mortar, is studied. The flow diagram in Figure 3.25
shows the elements of composite marble tile production. The detailed environmental performance
data for this product may be viewed by opening the file C3020D.DBF under the File/Open menu
item in the BEES software.
Raw Materials Table 3.45 gives me constituents involved in the production of the marble matrix
and their proportions. It is assumed there is no loss of weight during casting.
Table 3.45 Composite Marble Tile Constituents
Constituent Physical Weight
•; :•;;:;; : ' •-.'. •: , ."... ; • ' ' •'--• "; (%) " '
Resin 23.1
i:,:::,:,;.:,.; ,„=, Fills ,,:,,„.',. , .„ ,,.' ..." 25.2,;::; iu';;..; ; ;.. .
:;*; -1: ;• " ?: •, . - • * ': Catalyst (MEKP) 0.2 '
::..;..': : :"., "'.' Pigment(ti02) 1.5
The resin percentage is an average based on data from four sources ranging from 19 % to 26 %
resin content. The remainder., of the matrix is composed of filler, catalyst, and pigment. The filler
is the largest portion of the matrix. Since calcium carbonate is the typical filler used for U.S.
composite marble tile production, it is the assumed filler material in the BEES model. The filler is
c<|rnposed of coarse and fine particles with a ratio of two parts coarse to one part fine. Filler
production involves the mining and grinding of calcium carbonate.
a^'i-i'ii'!'11' i i • 94
11 ill
-------
Composite Marble Tile
Figure 3.25 Composite Marble Tile Flow Chart
Resin is the second-most important ingredient used for the marble matrix. It is an unsaturated
polyester resin cross-linked with styrene monomer. The styrene content is assumed to range from
35 % to 55 %.
The main catalyst used in the United States for the marble matrix is Methyl Ethyl Ketone Peroxide
(MEKP). This catalyst is used as a solvent in the mixture of resin and filler, so is consumed in the
process. Its amount is assumed to be about 1 % of the resin content, or 0.235 % of the total
marble matrix.
A colorant may be used if necessary. 1'he quantity depends on the color required. The colorant is
usually added to the mixture before all the filler has been mixed. For the BEES study, titanium
dioxide at 1 % to 2 % is assumed.
Energy Requirements. Electricity is the only energy consumed in producing and casting the
resin-filler mixture for composite marble tile. Table 3.46 shows electricity use for composite
marble tile manufacturing.
Table 3.46 Energy Requirements for Composite Marble Tile Manufacturing
Fuel Use Manufacturing Energy
Electricity
0.047 MJ/kg (20.25 Btu/lb)
Emissions. The chief emission from composite marble tile manufacturing is fugitive styrene,
95
-------
II! ) II
in i ii in
lull III i HI
III1 1111
>,( ',1
II id'
'Hii;,: :,i,;.
I!/"ft, ,,',
Chichi ariseg from the r^sin constituent and is assumed to be 2 °/o of the resin input. There could
be some emissions from the solvent, but most manufacturers now use water-based solvents, which
do not release any pollutants.
. i
Use. Installing composite marble tile requires a sub-floor of a compatible type, such as concrete.
A layer of mortar is used at 2.26 kg/0.09 m2 (4.98 Ib/ft2), assuming a 1.3 cm (1/2 in) thick layer.
It is assumed that composite marble tile has a useful life of 75 years.
iiii111 '' "I i i rot: nil' • i.:1': :• : :i n ,.: • ,i • -i, • ?. •> i: >. -,:;> • , >n • r, •,. .• t«,ll!;. n. >. i i - ,•« T-i« <• t «.,••:•. * i • i
Cos/1. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCpSTS;DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES, code C3020, product code DO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
Snd data are available, of operation, maintenance, and repair). First cost data are collected from
lie R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
i i ii ,i ' ii? ,ii :':^M iii Li i.i.v.'"^.^.'^''':.'*'^, ',;• ; '•' '• i i' in i i ' : i n
1111 I 1 111 I ' 111 I I ! !l 11 I 11 II HI I Ml I I I I
Eppxy terrazzo is a type of composition flooring. It contains a high proportion of inorganic filler
(principally marble dust and chips), a pigment for aesthetic purposes, and epoxy resin. The
materials are mixed and installed directly on site and, when dry, are carefully polished. Figure
3.26 shows the elements of terrazzo flooring production. The detailed environmental
rjerformance data for this product may be viewed by opening the file C3020E.DBF under the
File/Open menu item in the BEES' software
Raw Materials Table 3.47 lists the constituents of epoxy terrazzo and their proportions.
""," :!"• fable 3.47 Terrazzo Constituents ""
Terrazzo Constituents Physical Weight (%)
"" i ' i! i! ':' marMe~|u|t ;;\ ; ;;\\";;/:,;;:"^ITIV".!'" ''.'.. '.
epoxy resin 77
pigment (titanium dioxide) 1
The finished floor is assumed to be 9.5 mm (3/8 in) thick. Typical amounts of raw materials used
are as follows: 1.5 kg (3.3 Ib) of marble dust and 0.23 kg (0.5 Ib) of marble chips per 0.09 m2 (1
ft2), 3.8 L (1 gal) of epoxy resin to cover 0.8 m2 (8.5 ft2) of surface, and depending on customer
selection, from 1 % to 15 % of the total content is pigment.
Ill I , ri""' ',"t ' ' .':'' "''Sjl1,: • fil . .• ' ;;" i1 ' ;', nil r,.,1 i ".,1
The production of these raw materials, including the quarrying of marble, is based on the
Ecobalance LCA database. Note that because marble dust i§ assumed to fee § goproduct rather
than a waste byproduct of marble production, a portion of the burdens of marble quarrying is
allocated to marble dust production.
96
-------
Terrazzo
Functional Unit of Epoxy Tenrazzo
-Energy—
Energy-
Energy
Figure 3.26 Epoxy Terrazzo Flow Chart
Energy Requirements. The energy requirements for the on-site "manufacturing" process involve
mixing in an 8hp gasoline-powered mixer (a 0.25 m3, or 9 ft3 mixer running for 5 min).
Emissions. Emissions associated with the mixing process arise from the combustion of gasoline
and are based on AP-42 emission factors.
Use. Installing epoxy terrazzo requires a sub-floor of a compatible type, such as concrete. It is
assumed that epoxy terrazzo flooring has a useful life of 75 years.
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code C3020, product code EO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). First cost data are collected from
the R.S. Means publication, 2000 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
97
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iililillliiilil i '' i ' 'ill lilliliinhi
Illllll I II
3.8.6 Carpeting — General Information
Carpets are composed of a facing and a backing, which are attached during manufacture. Before
assembly, most carpets fibers are dyed. Adhesives are typically used for commercial installations.
Each of these components is discussed in turn, followed by a discussion of the manufacturing
process.
i
Carpet facing. Carpets are manufactured from a variety of fibers, usually nylon, polyester, olefin,
•or" wool. '" '" "'" " ' " """""" "
jCarpet dyes. Dyes are applied to textile fibers in a number of ways, depending on the properties
of the fiber, the dye, and the final product. The types of dyes used include inorganic, moralized
•III 111" i11M •• 'ij'iMiLlM " •Alillllilllil OPnur I 'i' ».i ...I: ii HI , r ,A 1.1, ,i, M »i , ii *^ •!« ii,: "
organic, acid, dispersed, premetallized, and chrome dyes.
'Carpet backing.
• Primary backing — usually made of either woven slit-film polypropylene or synthetic
nonwoven polyester or polyester/nylon.
in i in i i i i i'1 ; '">•:• /,"•"!:"";' v;i •• . i ii i
• Secondary backing - usually a woven or nonwoven fabric reinforcement laminated to the back
of tufted carpeting (often with a styrene butadiene latex adhesive) to enhance dimensional
stability, strength, stretch resistance, lie-flat stiffness, and handling. Most secondary backings
are woven jute, woven polypropylene, or nonwoven polypropylene, although some
manufacturers use propylene-polyethylene and polyvinyl chloride backings. The term
"secpn^ary backing" is sometimes used in a broader sense to include an attached cushion and
oth§r polymeric back coatings. Because secondary backing is visible in finished carpeting
(while primary backing is concealed under the pile yarn), most dealers and installers refer to
the secondary backing simply as "backing".
Carpet adhesives. Two types of carpet adhesive comprise most of the commercial market — latex
and pressure sensitive adhesives. Low-VOC styrene butadiene latex adhesives are thought to be
an environmentally-friendly adhesive alternative.
Sarpet manufacture and fabrication. Carpet manufacture consists of a number of steps,
including formation of the synthetic fibers; dyeing of the fibers; and construction, treatment, and
finishing ofgie carpet.
in iiiiiii ii ., i1' I-1?1 i:. .u. iSiiii' ' 'Sii, •"siiii lo;,1;;!,. •, ::l'l|i:i, itm:.!-,,'a :ui; Laftcf •«•• .1 IK,iiiii*,,, ,•••,..•<• t^^.,1 .• i •. • w. fJ1
• Forming synthetic fibers - nylon, plefin, and poly£ster are all thermoplastic, rnelt-spun
synthetic fibers. Synthetic fibers are extruded and splidify as they cool. Post-treatments
generally enhance the physical properties of the fiber. The bundle of fibers is then put through
a crimping or texturizing process, after which it is either chopped into staple fiber or wound
into bulk continuous filament yarn. The yarn may be heat-set to improve its ability to
1111 | j I I I I I l,ii|< " ,'ijnii .III II i.llllll, , illllilhli '.ill,1 ,,i ,:,/1. mil, I" 'llhlili1 ',"'' ,: 111,' " lli.i,' lln" UK i1 , ,1', in' 11 |
Withstand the stresses of dyeing, finishing, and traffic wear. Heat-setting is performed either
by the autoclave method, hi which batches of the yarn are treated with pressurized steam, or
the continuous method, in which the yarn is heat-set in an ongoing manner.
98
-------
• Dyeing fibers - polymer, fiber, or yarn can be dyed before carpet is manufactured by applying
the color through one of several processes: '.
1. Solution dyeing - involves adding color pigments to the molten polymer prior to
extrusion; |
2. Stock dyeing - cut staple fiber is packed into a large kettle after which dye liquid is
forced through the fibers continuously as the temperature is increased. This process is
often used to dye wool fiber;
3. Package dyeing - yarn is wound onto a special perforated cone; or
4. Space dyeing - involves knitting plain circular-knit tubing, which is then printed with
dyestuffs in a multicolored pattern, steamed, washed, extracted, dried, and then
unraveled and rewound into cones.
• Construction, treatment and finishing techniques - several different techniques are used to
attach yarn to the carpet backing. Tufting is by far the most widespread, with weaving,
knitting, fusion bonding, and custom tufting also in use.
1. Tufting - the yarn is stitched through a fabric backing, creating a loop called a tuft;
2. Weaving - carpet looms weave colored pile yarns and backing yarns into a carpet,
which then gets a back coating, usually of latex, for stability;
3. Knitting - carpet knitting machines produce facing and backing simultaneously, with
three sets of needles to loop pile yarn, backing yarn, and stitching yarn together;
4. Fusion bonding - the yarn is embedded between two parallel sheets of adhesive-coated
backing, and the sheets are slit, forming two pieces of cut pile carpet; and
5. Custom tufting - special designs are created using motorized hand tools called single-
handed tufters and pass macliines.
Commercial-grade carpet for medium traffic is evaluated for the BEES system. Two applications
are studied: broadloom and carpet tile. The tufting manufacturing process is assumed for all
carpet alternatives. Three face fiber materials are studied: wool, nylon, and recycled polyester
(from soft drink PET bottles). The primary backing for all carpets is comprised of a plastic
compound into which the face yarn is inserted by tufting needles. Also, a coating is applied to the
back of the carpet to secure the face yatrns to the primary backing. As carpet manufacturing and
installation are assumed to be similar for the three face fiber options, the corresponding modeling
is displayed only once in this general carpet information section.;
Energy Requirements, Table 3.48 displays the energy requirements for tufting carpet.91
91 J. Potting and K. Blok, Life Cycle Assessment of Four Types of Floor Covering, Utrecht University, The
Netherlands, 1994.
99
-------
Jill!!!*•, ',iii' r.(1''i'
iii'in,
f'-Ll-:
Table 3.48 Energy Requirements for Carpet Manufacturing
Fuel Type Manufacturing Energy
Electricity
Natural gas
1.80 MJ/m2 (0.046 kW»h/ft2)
8.2 MJ/m2 (0.21 kW.h /ft2)
Emissions. Emissions associated with fuel combustion for carpet manufacture are based on AP-
42 emission factors.
Use, Glue is typically used for commercial carpet installations. Two glue alternatives are
evaluated: traditional latex glue and low-VOC latex glue. Details on these carpet installation
parameters are given in Table 3.49.
11 ii i i in n n i i in
Table 3.49 Carpet Installation Parameters
Parameter
Broadloom
Tiley
Glue application
(applies to both
traditional and low-
iiiVpC glues)
',. KIM: "i,, ilUltlH'' 'iS'llKlllillo
;•• t , ,. ,,
Cutting waste
2 layers:93 1 layer at 8.8 square
• one Ml layer of glue, spread rate of m2/L (40 ydVgal)
1.77 m2/L (8 yd2/gal) _
• spots of glue (10 % of Ml spread
of glue with spread rate of4.42
m2/L, or 20 yd2/gal)
"' ":' '"" •'"" •"' ' ?T%" """":" ' "' "' ' : ' """ 2%
t (' In1,
"1 ".,*'
i./'MII.-I1'MHI-IL;'MHi ,fHl ,", !•;•,."; ' 'i"!1. .:;:• n '• ,""!"'• i,* "Hi "I" : *j , , ~ ",;.i".:i •>. :.«. • \- 'iO" rfbac" 4 ', •" ,•>.•.•• y ,
Data for production of the traditional and low-VOC glues are based on the Ecobalance LCA
f. I '' Sjull llilli;''.'I •" ill1, !•' l;li,i.r • ,n. • • :,-, ;• • • , • ••• • .• ,!•'••,,.« ,i' "i,,, i • M "„ i n .•:,! ••!.- • •
database.
• '•: ||'/ :""':>fplil' iiili• !"•'-;:;;S':i'i;:|;l $i '^; <::=":•• '$$•*::t|W'* iM1'1 ^!* ;• 'ill;•'||"t
-------
Truck Transport
Functional Unit of
Wool Carpet
Wool Carpet
Manufacturing
Wool Fiber
Mfg
Truck Transport
(Raw Mall's)
Primary
Backing
Mfg
(PPor
PVC)
Coating
Mfg
Figure 3.27 Wool Carpet Flow Chart
Raw materials. Table 3.50 lists the constituents of wool carpet and their amounts.
Table 3.50 Wool Carpet Constituents
Amount
Constituent
Material
Face fiber
Backing
Wool
Polypropylene for
broadloom,
PVC for tile
Styrene butadiene latex
1400 (4.59)
130 (0.43)
950 (3.11), including 710 g
(25.04 oz) of limestone as a
filler
The production of the plastic compound for backing, either polypropylene or PVC, and the
production of the styrene butadiene latex are based on the Ecobalance LCA database.
The wool fiber is produced in New Zealand, following the major production steps displayed in
Figure 3.28.
101
-------
I1; ii ., . „ '. i -' .
--""'• '"-• ' .'• "-'• •'• • '"•'>' • "— "• -
iljll . , 1". , "IIV ]•;! di I- ,|; fffliV 111
;,,!, , ....... ,,... ,,n Fertilizer .
Producilon '
* iilii ,:" •('«'- »i" ' ': ": 'ii: v" in i ill: i.'fi
gilt ; '„,! , "t '. ' , lii'i :,!,; : y BT- full "il
Silti,:11' 1 ',!;! I » ' filtilik i;,:,;: .•.:•,', '(''iKii1' II III
fSB; '!•• :.," MI mi :* • .•!;•:: ">'« -^ . 11 ^
(The material flows included
ri"! ' i MI n |L iiiv1' •BS'i i" ''"i1 • i i;."1;,,!!'11"!!"!!" '.
iin, rini; , "i" ill : JILMSI! ,; -ii > , I"1, .'. l;;1;llllill!l:lillli| -
i iikiini'1'1 . if i ,i ,"•.', ' iiiiiiiiiu' ^li-"1 " ,.,•,,.,
.-.: , • :, .;; -L FlOW
^^|J':I*:""IN"'^;.*'-<'V''_'; ";
Sheep
Food k Raising b W
Production ' and w Sco
Shearing
••::-,. •; T. - •,:. it,.,' •:...
Wool
30! fc Drying,
jring ' Dyeing,
Blending
'•:^::'!
b,
j il
li1,'1!, ,i ; >>:l ', ' " '".nil1 ! ;':, 'l| j,,,:1! ! ' Hlpi1 , III Hull T^, ;,,, K^^l
'I'Vii":;!'/: ''lifsyt, •• • '•!' ' ' i,i }"M!< 1 [ill - :;f ! i:!''":'! !•
: wool , ^1
Carding ^H
and ^H
Spinning ^^1
Figure 3.28 Wool Fiber Production
for the production of raw wool are displayed ir
Table 3.51 Raw Wool Material Flows
Table 3.5 1.54 ' •
Amount H
"Inputs: """" " " ' •
II II
Illlli II II 111
- Nitrogen supply (ammonium nitrate)
- Phosphate supply (P2O5)
Outputs:
=i;; i1 Raw wool
- MeAane emissions (enteric
fermentation)
29 g of nitrogenTkg raw wool (0.46 oz/lb)
770 g of P2O5/kg raw wool (12.32 oz/lb)
!|
5.5 kg (12.13 Ib) of raw wool / 8 month period
8.8 kg (19.4 Ib) / head / year
"Average of data reported m two sources: international Panel on Climate Change for methane, 1993, reports 9.62
kg/head/y and AP-42, Table 14-4-2, gives 8 kg/head/yr.
! i 111 i i 111 i I ' i III i I il nil i u i i I
ffhe fertilizer inputs correspond to the production of food for the sheep. Fertilizer production is
"il It i K ..j .Ill IC'J™ .,,,„.. .••v'.S'i' '* v '' *-' " • "ll»" '••'' -1 ' '• " ^' " ""'•'• """'' ' : «
based on the Ecobalance LCA database.
J^wwoipl is greasy'and carries debris that needs to be washed off in a process called "scouring."
The amount of washed wool per kg of raw wool is 80 %, as shown in Table 3.52 along with other
raw'wool constituents.
; ,:|: ii;;';;'" ';1J" .^ , Igj [^!;::!: "'jj^S fable 3,52 Raw Wool Constituents
freight (%)"
Clean fiber (ready to be carded and spun)
Grease
Suint salts
Dirt
80
"" 6
6
Grease is recovered at an average recovery rate of 40 %.95 The scoured fiber is then dried,
carded, and spun. Table 3.53 lists the main inflows and outflows for the production of wool yarn
from raw wool,96 The data for raw wool processing are from the Wool Research Organisation of
£jew Zealand (WRONZ). "
®4 J.fotting and K.Blok, Life Cycle Assessment of Four Types of Floor Covering, Utrecht University, The
Netherlands, 1994.
95 The non-recovered grease exits the system (e.g., as sludge from water effluent treatment).
96 These requirements also include processes such as dyeing and blending which take place at this stage.
102
-------
Flow
Table 3.53 Wool Yarn Production Requirements
Amount
Input:
- Natural Gas
- Electricity
- Lubricant
- Water
Output:
- Wool yarn (taking into account material
losses through drying, carding, and
spinning)
-Water emissions corresponding to scouring:
BOD
COD
4.3MJ/kg(1849Btu/lb)
0.56 MJ/kg (241 Btu/lb)
0.05 kg/kg (0.05 oz/oz)
30 L/kg (3.59 gal/lb)
0.75 kg/kg (0.75 oz/oz)
3.3 g/kg (0.053 oz/lb)
9.3g/kg(0.15oz/lb)
Most of the required energy is used at the scouring step. As grease is a co-product of the scouring
process, a mass-based allocation is used to determine how much of the energy entering this
process is actually due to the production of washed wool alone.97 One-fourth of the required
energy (about 1MJ, or 948 Btu) is used for drying.98 Energy requirements with regard to wool
carding and spinning are negligible. Water consumption is assumed to be 20 L/kg to 40 L/kg (2.4
gal/lb to 4.8 gal/lb) of greasy wool. Lubricant is added for blending, carding, and spinning. Some
lubricant is incorporated into the wool.
Transportation. Backing and coating raw materials are assumed to travel 402 km (250 mi) to the
carpet manufacturing plant. Wool yam comes from New Zealand. Table 3.54 displays the
transportation modes and distances the wool travels before being used in the tufting process.
Table 3.54 Wool Transportation
Mode of Transportation
Distance
Sea Freighter
Truck
11112 km (6,000 nautical miles)
805 km (500 mi)
Use. Refer to section 2.1.3 for indoor air performance assumptions for this product.
Cost. Purchase and installation costs for wool carpet vary by application (broadloom or tile) and
glue type (traditional or low-VOC). The detailed life-cycle cost data may be viewed by opening
the file LCCOSTS.DBF under the File/Open menu item in the BEES software. Costs are listed
under the following codes
• C3020, GO—Wool Carpet Tile with Traditional Glue '.
This allocation is also applied to the non-energy flows for this process;
98 Including dyeing and blending.
103
-------
II
II n
1111111 III 1 III 111 III II III II 1 III 1 1 1 II II II II
• ii ^H
(Ill
111
Pllll',, H i, uLflllll lill IP
;,:,,; •; ;, ,: ..... ;;,„
....... i fi;:
'
EiS
S C3020, JO—Wool Carpet Tile with Low-VOC Glue
• C3020 MO—Wool Broadloom Carpet with Traditional Glue
• C30205Pp-zWpol Broadloom Carpet with Low-VOC Glue
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
7cost an& j^quency of replacement, and where appropriate and data are available, of operation,
' liafnf enance I aflS''repair)! First'cost data are" collected ""from the R.S! Means' publication, 2000
/'jjuiiding Construction Cost Data, and future cost data are based on data published by Whitestone
1 "Reseaicfi inT The Whitestone Building Maintenance and Repair Cost Reference 1999,
supplemented by industry interviews.
3.8.8 Nylon Carpet (C3020F,C3020I,C3020L,C3020O)
A 0.68 kg (24 oz) nylon carpet with an 1 1 year life is included in BEES. Figure 3.29 displays the
system under study for nylon carpet manufacture. The detailed environmental performance data
for tiiis product may be viewed by opening the following files under the File/Open menu item in
'(!>• iipi ..... ..... "^••jj&Jiz ..... « ............... 11 ' ....... ............ • ••" ..... < - ...... ......... • ...... ••• ........................... ........... ............. ...... • -I- ........ - •> ....... - ..... ........ ' ........ •• .............................. •'" ....... ••• ..... ............................ ........ ................ . ........ ...................
: the BEES software:
; • III" ...... ft"vv:fe ..... M'm&'M'if: ...... J :y^W.Y< ..... ^l^-"!!-!::,:;^!!.^
..... " "' " ' l" ' ' '" ' 1 " ' ' ' • 11 • " ''
" !' '
:•:;; '• -jg,:^iQp20L.pBF—Nylon Broadloom Carpet with Traditional Glue
— Nyon Broadoom Carpet with Low-VOC
Matenals. Table 335 lists the constituents of nylon carpet and their amounts.
Table 5.55 Nylon Carpet Constituents
, s™!,; :. '^"Constituent
'
Material
Amount
:',:Face ..... fiber
Backing
Nylon 6,6
Polypropylene for
broadloom,
PVC for tile
Styrene butadiene latex
810(2.65)
130(0.43)
..... IT , ,,, ..... ..... ,, ,
930 i ^.'65)', mciuding :"7iO'g
(25l04 oz) of limestone as a filler
The production of the plastic compound for backing (either polypropylene or PVC), the styrene
butadiene latex, and the nylon fiber are based on the Ecobalance LCA database.
|:,,jke''spinningof nylon fiber is based on melt extrusion, for which the Association of Plastic
Manufacturers in Europe (APME) is the data source for energy requirements and AP-42 the data
source for emissions. The inputs and outputs of the nylon yarn manufacturing process are
displayed in Table 3.56.
104
-------
Truck Transport
Functional Unit of
Nylon Carpet
Nylon Carpet
Manufacturing
Nylon Fiber
Mfg
Truck Transport
(Raw Mall's)
Primary
Backing
Mfg
(PPor
PVC)
Coating
Mfg
Flow
Figure 3.29 Nylon Carpet Flow Chart
Table 3.56 Nylon Yarn Production Requirements
Amount
Input:
- Electricity
-Fuel Oil
- Natural gas
Output (emissions to the air):
- Hydrocarbons except methane
- Participates
1.8MJ/kg(774Btu/lb)
0.7MJ/kg(301Btu/lb)
0.2 MJ/kg (86 Btu/lb)
2.3 g/kg (0.037 oz/lb)
0.6 g/kg (0.0096 oz/lb)
Transportation. Transport of raw materials to the carpet manufacturing plant is assumed to
require 402 km (250 mi) by truck.
Use. Refer to section 2.1.3 for indoor air performance assumptions for this product.
Cost. Purchase and installation costs for nylon carpet vary by application (broadloom or tile) and
glue type (traditional or low-VOC). The detailed life-cycle cost data may be viewed by opening
the file LCCOSTS.DBF under the File/Open menu item in the BEES software. Costs are listed
under the following codes: \
105
-------
Hlf !
i 1-i1'"!,!":*
• C3p20,FO—Nyjlpn Carpet Tile with Traditional Glue
ii,;;iQplP^—Nylon Carpetfile with Low-VOC Glue
• C302o"LO—ISfylon Broadloom Carpet with Traditional Glue
lit1!,1"!!; liiiJIKIi'JB'i'lll.' f'illfliii, IlillljOl!!!!1 iHiM" r,!,!,;!.i-mn!" i, «-, I, ,
* C3020,OO—Nylon Broadloom Carpet with Low-VOC Glue
I ''.h'llllir' Ill'l1''!!'"' [!„>,
Iliijlii1; ' I1 i il ''.IT
it IK*
ilNIIII!'!
•Bi1
il
•ilF
I i1 t >-
'.'F".l', 'Hi
1" i IS'
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
aii!1! ; M.|I iur ihiiniiHd'i'PiM'l iiiii.iiiiiiiiiiii!ii ' '.MLJiiir HI m P ui n , nil" ;.,ii -',.'" • " •" ,.,'T i, ir i.'vii'!1 inunmi'i ,,i ii"1::,,,!1*1',!11'!"!. "' M,,":'! iw'iiiv'fidiii,1, .11 ^stfti::» i, i»"ii "i .iini »!»Hiii. i: imii n i.ii!'i niii\,, ..i ^ u •, ".1,1. nwx' ,1 ,NW mi,;!11 n, •*
(cost and jBrequency of replacement, and where appropriate and data are available, of operation,
"^^htenance, and repair). First cost data are collected from the R.S. Means publication, 2000
"Building Construction Cost Data, and future cost data are based on data published by Whitestone
Research in The Whitestone Building Maintenance and Repair Cost Reference 1999,
lupplemented by industry interviews.
XliLMm ' i I III III II I I III I II I I I I 111 I III
318.9 Recycled Polyester Carpet (C3020H,C3020K,C3020N,C3020Q)
A 0.68 kg (24 oz) carpet with polyester fiber recycled from soft drink bottles (PET) and with an 8
year life is included in BEES. Figure 3.30 displays the system under study for recycled polyester
carpel manufactured The detailed envifonmentarpefforrhance data for this product may be viewed
by bp"ening'1ne following files under the File/Open menu item in the BEES software:
* C3020H.DBF—E(ecyciea Polyester Carpet Tile with Traditional Glue
* C3020K.DBF—Recycled Polyester Carpet Tile with Low-VOC Glue
* C3020N.DBF—Recycled Polyester Broadloom Carpet with Traditional Glue
« C3020Q.DBF—Recycled Polyester Broadloom Carpet with Low-VOCGlue
Raw materials. Table 3.57 lists the constituents of recycled polyester carpet and their amounts.
" .'. „',!„' ',' ,"',,'' !' Table S3? Recycled Polyester Carpet Constituents
Constituent
" Material"
Amount
g/m2(oz/f?)
^Face fiber
Recycled PET ................................................. 81 0(2.65)
Polypropylene for .......... ^ _ ^ ......... .......... .................. 1 3 6 (0.4^3) ......
broadloom,
PVC for tile
Styrene butadiene latex
930 (3.05), including 710 g
(25.04 oz) of limestone as a filler
The production of the plastic compound for backing (either polypropylene or PVC), the styrene
butadiene latex, and the recycled PET fiber are based on the Ecobalance LCA database. Tfie
filiil'.liiljij.jijlllll III III Nllllllll I* J j
recychng of PET is modeled as shown in Figure 3.31.
ETI! ::
'1': "i1!
106
-------
Truck Transport
Functional Unit of
Recycled PET Carpet
Recycled PET
Carpet
Manufacturing
Recycled
PET
Fiber Mfg
Truck Transport
(Raw Mall's)
Primary
Backing
Mfg
(PPor
PVC)
Coating
Mfg
Figure 3.30 Recycled Polyester Carpet Flow Chart
-collected PET bottles->
PET Sorting
and Baling
Truck
Transport
—recycle
Figure 3.31 Handling and Reclamation of PET
The spinning of the PET fiber is based on melt extrusion, for which the Association of Plastic
Manufacturers in Europe (APME) is the data source for energy requirements and AP-42 the data
source for emissions. The inputs and outputs of the recycled PET yarn manufacturing process are
displayed in Table 3.58.
Table 3.58 Recycled PET Yarn Production Requirements
Flow Amount
Input:
- Electricity
- Fuel Oil
- Natural Gas
1.8MJ/kg(774Btu/lb)
0.7 MJ/kg (301 Btu/lb)
0.2 MJ/kg (86 Btu/lb)
107
-------
II
>*["!'•1 ''i;,.!';
Illii'1!: I",, li'hi' II '"'!: ' Illl
Illltil'Mil' I i": II ''ifihii
,!'!>"!!"! ;*»>'".\ltV, IB '<•'•• « 'fill'"'! I! "I'l
l'u'i:ut (^^ipns^o^e air): ^
. p^, ^^ ^^ M^'^^^arfcons except niethane O^'OS g/kg (0.
" , i Pi!,.,, ^i''l''''l|!^ i'l'iJi1, '!'''!,|1, ' iiliir'i!i L ' Ajll ! ' Jii1'1'1'1111"11' ''ill1'1' ' :i'i"' '""'l'i'""i' ' l'll"|l|l|l!lll"'l: " ' "'" "' li»*iiiiiii|'i|i|i|1|i1''1 i!"'"! 'I""ii.I"i1 41, i ,iiiM.iiii.iii3i«liiiiiiii"ii mii'iiii ,* I'liii^,,^,*,!
111 _.. . '.. .: ' ' ' -, Particulates
nil1!, i.if'iia:"! ii,11
o:
•;,!(:l,l,l-,!Wlilii!!lli!t III'1:1!,.:!1!1.!'
!, '. iiHSij:: II iHI id'J, i V'1
"J..«!ifM*. illiiS. .'*
"Ill III! ' iMlMlllllll
i.it I!' .'llTTl'l'W , ' Ini'SIlL i|| !:,<;
Transportation. Transport of raw materials to the carpet manufacturing plant is assumed to
require 402 km (250 miyty true!. Another 274 Icni "(H6 "mi) is a33eH for tonsport of the recycled
from the materials recovery facility to me recycled yarn processing site.
tfse. Refer to section 2.1.3 for indoor air performance assumptions for this product.
..... I
Cost. Purchase and installation costs for recycled PET carpet vary by application (broadloom or
tile) and glue type (traditional or low-VOC). The detailed life-cycle cost data may be viewed by
"opening ..... me"""gie: ...... LditS'^^D^'und.^^'^^! ..... File/Open'menu'item ..... m"the ...... BEES ...... software". Cos'ts"are .....
listed under the following codes:
• C3:020,HO—Recycled Polyester Carpet Tile with Traditional Glue
• " C3b20,KO-^" Recycied Polyester Carpet"Tile" with Low-VOC Glue
• C3020,NO-=Recycled Polyester Broadloom Carpet with Tfadltibnal Glue
• C3020,QO—Recycled Polyester Broadloom Carpet with Low-VOC Glue
Life-cycle cost data include first cost data (purchase and installation costs) and future cost data
(cost and frequency of replacement, and where appropriate and data are available, of operation,
maintenance, and repair). First cost data are collected from the R.S. Means publication, 2000
Building Construction Cost Data, and future cost data are based on data published by Whitestone
Research "m The Whitestone Bmiiding Mamtenance and Repair "Cost Reference 1999,
supplemente3 by industry interviews.
3.9 Parking Lot and Driveway Paving Alternatives (G2022,G2031)
I ,. .,.',,. i : i* ,| i
3.9.1 Concrete Paving (G2022A, G2022B, G2022C, G2031A, G2031B, G2031C)
1 ill i i ii IHI i — 'ib • ;jiri< iviii'i'L 'i I1,i;"11'' • i''1''! • i,,,|!ii,1 " 'I'viiiiiiiiK1 '••'' I:"I ];':.',,!',<, i n j i t in i i i i in n i m I
For the BEES system, concrete paving consists of a 15 cm (6 in) layer of concrete poured over a
20 cm (8 in) base layer of crushed stone. The three concrete paving alternatives have varying
degrees of ily ash in the portlaiicl cement (0 %, 15 %, arid 20 % fly ash). Section 3.1 describes
the production of concrete. For the paving alternatives, a compressive strength of 21 MPa (3000
psi) is used. The flow diagram shown in Figure 3.32 shows the elements of concrete paving. The
Detailed environmental performance data for concrete paving may be viewed by opening me
following files under the File/Open menu item in the BEES software:
• G2022A.DBF—0 % Fly Ash Content Concrete
-F" ^G^OJ^BfDBF—15 % Fry Ash Content Concrete
••'"' G2022CDBF—20 %" Fly' A^ Content "Concrete"
108
-------
Coarse Fine PC
Aggregate Aggregate y s C
Production Production iransport pro
V 1 ' V V
,-, . Stone
Concrete „ ,
Produ
1
Transportation
(truck)
80-322-483 km sensitivit;
'. (50-200-300 mi)
i r
Installation — Wa
|
>rtland
ement
duction
Base
iction
r
ste-*-
Figure 3.32 Concrete Paving Flow Chart
Raw Materials. The materials required to produce concrete are given in Section 3.1.
The amount of material used per functional unit (0.09 m2, or 1 ft2of paving for 50 years) is 32.9
kg (72.5 Ib) of concrete and 33.3 kg (73.3 Ib) of crushed stone.
Energy Requirements. The energy requirements for concrete production are outlined in Section
3.1. The energy required for site preparation and placement of crushed stone is 0.7 MJ/ ft2 of
paving, and the energy required for concrete placement is included in transportation to the site.
Emissions. Emissions associated with the manufacture of concrete are based on primary data
from the portland cement industry as described in Section 3.1. In addition, for the concrete
paving option, upstream emissions data for the production of fuels and electricity are added to the
industry emissions data.
Transportation. Transport of raw materials is taken into account. Transport of the concrete to
the building site is a variable of the BEES model.
Use. A light-colored paving material, such as concrete, will contribute less to the "urban heat
island" effect than a dark-colored paving material, such as asphalt. These differences are not
accounted for in BEES, but should be factored into interpretation of the results.
Cost. The detailed life-cycle cost data, for concrete paving may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Costs are listed under the
109
-------
Transportation
(track)
80-322-483 km sensitivity
(50-200-300 mi)
Figure 3.33 Asphalt with GSB88 Emulsion Maintenance Flow Chart
Table 3.59 Raw Materials for Asphalt Base Layer
Constituent
Percent of Percent of
Base Layer Component
(by weight) (by weight)
- Hot Mix Asphalt (binder course) 71.4
- Gravel
- Asphalt
- Hot Mix Asphalt (wearing course) 28.5
- Gravel
- Asphalt
-Tack Coat 0.1
- Asphalt
- Water
- Emulsifier
-HC1
95
5
94
6
66
33
1.1
0.2
asphalt emulsion maintenance over 50 years).
Energy Requirements. The energy requirements for producing the base layer's hot mix asphalt,
for installing the base layer, and for applying the GSB88 emulsion maintenance are listed in Table
3.60.
Ill
-------
for this product may be viewed by opening the file G2022E.DBF under the File/Open menu item
in the BEES software.
HC1 Asplialt Emulsifier
Production Production Production
HC1
Production
' • • i • •
Asphalt Gravel
Production Production
1 1
Asphalt Gravel
Production Production
Diesel Fuel ' 1 1 ' Diesel Fuel ' 1 r~*
Production ~| . V 1 • Production ~| 1 1
1 ' HotMix '
* Asphalt TackCoat
— HotMix '
5 1
Production ^ T Production if
Base Layer
i
Asphalt
•• Cement
i
Transportation i
(track)
80-322-483 km sensitivity
(50-200-300 mi) i '
Diesel Fuel
Use in Installation .
tallation — Waste-*-
i : '•' • -
Asphalt Emulsifier
Production Production
TackCoat
(— '
Stone Base
Production
1
Figure 3.34 Asphalt with Asphalt Cement Maintenance Flow Chart
Raw Materials. The materials required to produce the asphalt base layer are identical to those
given in the previous section. The materials required to produce the asphalt cement maintenance
product are shown in Table 3.61.
The production of the raw materials required for both the pavement and its maintenance is based
on the Ecobalance database.
Table 3.61 Raw Materials for Asphalt Cement Maintenance
Percent of Percent of
Base Layer Component
Constituent (by weight) (by weight)
Asphalt Cement:
- Hot Mix Asphalt
- Gravel
- Asphalt
- Tack Coat
- Asphalt:
- Water
- Emulsifier
-HC1
99.4
• 95
5
0.6
66
; 33 ,
1.1
, 0.2
113
-------
i n nil I iiili i
Mif.- UL'!
•i Hi" n'n ' ii'iii',
EiliJILF
IK
Wl; '"""IHP""
II III III 11 IIII
I Hill,: if! Jw i ' 'II 'ill! '|,,!,||,
The amount of material used per functional unit (0.09 m2, or 1 ft2 of paving for 50 years) is 48 kg
(106 Ib) of asphalt, 33.3 kg (73.3 Ib) of crushed stone, and 6 installments of the asphalt cement
maintenance at 13.7 kg (30~3 Ib) each (for a total of 82.4 kg, of "ISO' Ib of asphalt cement
III Ml I II I 111 Illllll III 111 II Ilillll I '|,.'F,V & • ,i:\ V", • ••! ... ,S| |, ii».' , • •• , •!• ,,.-,', ;... -i
maintenance over 50 years).
Energy Requirements. The energy requirements for producing and installing the original layer
of hot mix asphalt over a crushed stone base are shown in Table 3.60. The energy requirements
„ niiiiiiiiiiiiiiii jiii niii iiiini',
-------
HC1
Production
Asphalt
Production
Gravel
Production
Asphalt
Production
Emulsifier
Production
Transportation
(truck)
80-322-483 km sensitivity
(50-200-300 mi)
—Waste-V
Figure 3.35 Asphalt with Sealer Maintenance Flow Chart
Raw Materials. The materials required to produce the asphalt base layer are identical to those
shown in the section above, Asphalt Parking Lot Paving with Asphalt Emulsion Maintenance.
The materials required to produce the driveway sealer are shown in Table 3.63.
Table 3.63 Raw Materials for Driveway Sealer
Percent of Sealer
Constituent (by weight)
• Asphalt
• Water
• Acrylic Resin
• Detergent
• Emulsifier
Ammonia
47.5
39.6;
11
0.6 ;
0.6
o.i ;
The production of the raw materials required for both the asphalt base layer and the sealer are
based on the Ecobalance database.
The amount of material used per functional unit (0.09 m2, or 1 ft2 of paving for 50 years) is 48 kg
(106 Ib) of asphalt, 33.3 kg (73.3 Ib) of crushed stone, and 12 installments of the driveway sealer
maintenance at 0.054 kg (0.12 Ib) each (for a total of 0.65 kg, or 1.4 Ib of driveway sealer
maintenance over 50 years).
115
-------
I ill II I 111
' ''.nil11 ill:"' llin! I'lilli'ill"!
TEnergy Reqiiireinents. The energy requirements for producing and installing the base layer's hot
!taJx asphalt are listed in Table 3.60. The energy required for installing the asphalt sealer is shown
in f able'S.'S?.
Table 3.64 Energy Requirements for Asphalt Sealer Maintenance
III !'.?>. 1Lii.il,"'
•NIB Kir ii nil :<
Ill I II II 111
I!'•("'"ill!
;" ,. ^jFuel
Energy
'' -'''' " " »'• "P^i^Cf1!
' '. JLxiCoCi
'fl2"
•": iiWillire !, 'ill
lions. Emissions associated with the manufacture of hot mix asphalt are based on U.S. EPA
AP-42 emission factors. Emissions from the production of the upstream materials and energy
carriers are from the Ecobalance database.
j
. ., |||f ,l| i >,,l||, II ,|l|, ,||,',ll
Transportation. Transport of the raw materials is taken into account. Transport of the asphalt to
the building site is a variable of the BEES model.
in ii i i i i ill n 111 nun ii i i ii i i i i in i in i i i i 11 i ' ,«i 'I ,.]'''iM?{5
Cost. The detailed life-cycle cost data for this product may be viewed by opening the file
LCCOSTS.DBF under the File/Open menu item in the BEES software. Its costs are listed under
BEES code G2031, product code DO. Life-cycle cost data include first cost data (purchase and
installation costs) and future cost data (cost and frequency of replacement, and where appropriate
and data are available, of operation, maintenance, and repair). First cost data are collected from
trie R.S. Ivieans publication, 2060 Building Construction Cost Data, and future cost data are
based on data published by Whitestone Research in The Whitestone Building Maintenance and
Repair Cost Reference 1999, supplemented by industry interviews.
11 11(1 11 iiu i 11 Hi 111 i ii i i Hi i Hi mi
i I 1 1
116
ill in
in i
-------
4. BEES Tutorial
To balance the environmental and economic performance of building products, follow three main
steps:
1. Set your study parameters to customize key assumptions
2. Define the alternative building products for comparison. BEES results may be
computed once alternatives are defined.
3. View the BEES results to compare the overall environmental/economic
performance balance for your alternatives.
4.1 Setting Parameters
Select Analysis/Set Parameters from the BEES Main Menu to set your study parameters. A
window listing these parameters appears, as shown in Figure 4.1. Move around this window by
pressing the Tab key.
BEES uses importance weights to combine environmental and economic performance measures
into a single performance score. If you prefer not to weight the environmental and economic
performance measures, select the "no weighting" option. In this case, BEES will compute and
display only disaggregated performance results.
Assuming you have chosen to weight BEES results, you are asked to enter your relative
preference weights for environmental versus economic performance. These values must sum to
100. Enter a value between 0 and 100 for environmental performance reflecting your percentage
weighting. For example, if environmental performance is all-important, enter a value of 100. The
corresponding economic preference weight is automatically computed. Next you are asked to
select your relative preference weights for the environmental impact categories included in the
BEES environmental performance score: Global Warming Potential, Acidification Potential,
Eutrophication Potential, Natural Resource Depletion, Indoor Air Quality, and Solid Waste. (For
a select group of products, BEES 2.0 also includes Ecological Toxicity, Human Toxicity, Ozone
Depletion, and Smog. These "expanded impact" products are identified in Table 4.1.) You are
presented with four sets of alternative weights. You may choose to define your own set of
weights, or select a built-in weight set derived from an EPA Scientific Advisory Board study, a
Harvard University study, or a set of equal weights. Press View Weights to display the impact
category weights for all four weight sets, as shown in Figure 4.2. If you select the user-defined
weight set, you will be asked to enter weights for all impacts, as shown in Figure 4.3. These
weights must sum to 100.
117
-------
Figure 4.1 Setting Analysis Parameters
"IIIWI:!,!"1 !i..'.i'.|' i' II, I1.!!!!1'"!".
111.1'1 I1 ..'Win, "H "IF"HI
111
ill
I,!'"
118
-------
EPA Science Advisory Boar
27
13
13
13
27
Harvard University Study-ba
'28
17
18
15
12
101
Equal Weights
17
17
17
17
16
Figure 4.2 Viewing Impact Category Weights
Figure 4.3 Entering User-Defined Weights
119
-------
111 in i i n ii i
!, ! i' "i1" ""H, ni lil l!1
""ll"i"P ,!'".,!, i i "!„
O!W'M|! !i,;<:: ii'iX ! !!!' .'i:::!"'Illllil'l!
.". —I;T,,."". :'.; ;,~;' ;:II: Figure 4.4 Selecting Building Element for BEES Analysis
»i mini' I nil " i in i,, l|l|1|.,; sr i' ,; , ;i 1l» K < lli'i 'tin I , i "iin < ,1, > T < <> niiiiniii"' <:'' »i i ; i , ,riii»iiiii r. us1 • 'KII, '"'' 'iiinr, mi ir "i.iiiihiuuM, , ' i ! ......... iSiisi? ...... I n ..... SIS ..... ' I 'i'-'IM* si ..... .J . '• "i i (>• «'• " *! ...... !S» ........ ! "'tslii! , r, . . i*! .iiill ...... it.lt ...... SSt-iSlii-;1 • ,'!lt:,;' i 'If '4'fl1 »: * i*"i ..... l|:!iM :«' *;.4 :, ;"f (OCf i'-,1 V: /'it ' Sir! X J '111:: i' (*!'>• ...... i!
S!t :k '•''*; J, Select the building element for which you want to compare alternatives.
Building elements are organized using the hierarchical structure of the ASTM
.. ....... ^.'".O^ce^ofManagemen^and Budget (OMB) Circular A-94, ^ideUn^^mD^cqunt^^for^Beneftt-
jiaaiysis ofFederal'Programs, Washington, DC, October 27, 1992 and QMB Circular A-94, Appendix C,
February 2000.
120
i ii i
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standard UNIFORMAT II classification system.103 Click on the down arrows
to display the complete lists of available choices at each level of the hierarchy.
BEES 2.0 contains environmental and economic performance data for 65
products across 15 building elements: slabs on grade, basement walls, beams,
columns, roof sheathing, exterior wall finishes, wall insulation, wall sheathing,
framing, roof coverings, ceiling insulation, interior wall finishes, floor
coverings, parking lot paving, and driveways. Press Ok to select the choice in
view.
2. Once you have selected the building element, you are presented with a window
of product alternatives available for BEES scoring, such as in Figure 4.5.
Select an alternative with a mouse click. You must select at least two
alternatives. After selecting each alternative, you will be presented with a
window, such as in Figure 4.6, asking for the assumed distance for transporting
the product from the manufacturing plant to your building site.104
Composite Marble
Nylon Carpet Tile/Bio^Glue
Nylon fcarpet t ile/Synthet. Gtue
8j NylonCarpetBToadloomXBio-Glue,
NyloriCarpetB rpadlpom/SyntnG lue
ledPETCarpetBrdlm/BioGlue
RecycledPEJCarpetTile/'Bio-Slue
^ecycledPETCarpetTile/Syh.GlLie
Figure 4.5 Selecting Building Product Alternatives
103 American Society for Testing and Materials, Standard Classification for Building Elements and Related
Sitework-UNIFORMATII, ASTM Designation E 1557-96, West Conshohocken, PA, 1996.
104 If you have chosen the wall insulation element, you will first be asked for parameter values so that heating
and cooling energy use over the 50-year study period can be properly estimated. If you have chosen roof coverings
and installation will be in a U.S. Sunbelt climate, you will be asked for parameter values that will permit
accounting of 50-year heating and cooling energy use based on roof covering color. If you have chosen concrete
beams or columns, you will be asked for assumed compressive strength.
121
-------
; i 4 ;,i 1; ; h
•> i I™ • i'1'.' ^M
I
I'lllli K'W II Ill1 "
4illl:i;;,;f,!l iflil
i iPiiiin ,, i nii'< i IF 'i' ii'i,mil,,
I1 Ji, 'iHJiiii,!;,, • i1'ill, j ii
}*$&'• '^:^ ®^
11,,,111,,111111'lllliJIII1: ," !'«'I|l||ll||||||l|i, ' jjlll'i, ,7" • inllll ; ,1111 J,:,,!"!1 f 'K,,Sf''" mill" 'i1in'i|li''1|!li:ii .."i.ii.hl'IILilll' ,','H, H'lillHlill ,, T|1Ji':ll,:WVillli '91 \'IHMii,i!!''lln illliiri'illilllipilillilllliilillKf1!, "I ItljilllliLi,1'!;11,1, INillll'IIIKilllEJl L'!'!l:7'I|Bi|l!;, 'I'll "in1;1 |"li;J',,,1; ii;i!f"!,i '' 'i .i.lf V1!"11, i „ , '" W
y,'*'•.,
r
-------
BEES results are derived by using the BEES methodology to combine the BEES environmental
and economic performance data using your study parafneters. The methodology is described in
section 2. The detailed BEES environmental and economic performance data, documented in
section 3, may be browsed by selecting File/Open from the Main Menu.
From the window for selecting BEES reports, you may choose to display a summary table
showing the derivation of summary scores, graphs depicting results by life-cycle stage and by
contributing flow for each environmental impact category, graphs depicting embodied energy
performance, and an All Tables in One option reporting detailed results in tabular form. Figures
4.11 through 4.15 illustrate each of these options105.
To compare BEES results based on different parameter settings, either bring the summary table in
focus and select Analysis/Set Parameters from the Main Menu, or press the Change Parameters
button on the summary table. Change your parameters, and press Ok. You may now display
reports based on your new parameters. You may find it convenient to view reports with different
parameter settings side-by-side by selecting Window/Tile from the Main Menu. Note that
parameter settings are displayed on the table corresponding to each graph.
4.4 Browsing Environmental and Economic Performance Data
The BEES environmental and economic; performance data may be browsed by selecting File/Open
from the Main Menu. Environmental <3ata files are specific to products, while there is a single
economic data file, LCCOSTS.DBF, with cost data for all products. As explained in section 3,
some environmental data files map to a product in more than one application, while the economic
data vary for each application. Table 4.1 lists the products by environmental data file name (all
with the .DBF extension) and by code number within the economic performance data file
LCCOSTS.DBF. Table 4.1 also indicates the number of environmental impacts available for
scoring for each product.106
The environmental performance data files are similarly structured, with 3 simulations in each. The
first column in all these files, "Xport," shows compressive strength (in MPa) for concrete
products except concrete paving, or transportation distance from manufacture to use (in miles) for
all other products. All files contain 3 sets of inventory data corresponding to the 3 simulations.
For each simulation, the environmental performance data file lists a number of environmental
flows. Flows marked "(r)" are raw materials inputs, "(a)" air emissions, "(ar)"
105 Detailed results for the Indoor Air Quality impact are not reported because this impact is evaluated
differently for each relevant building element. Refer to section 2.1.3 for detailed Indoor Air Quality results, and
look for summary Indoor Air Quality scores in the BEES summary reports.1
106 Since floor coverings includes a mixture of six- and ten-impact products, if a six-impact product is selected
for BEES analysis together with a ten-impact product, both will be scored based on six impacts. Thus, linoleum
and vinyl composition tile may be scored based on ten impacts only by selecting these products alone.
123
-------
'^-'"'Figure 4.
radioactive air emissions",""'(w)"" water effluents, u(wr)" radioactive water effluents, "(s)" releases
to soil, and "E" energy usage. All quantities for concrete products except paving concrete are
given per "0™76 m3 (1 yd3) of concrete over 50 years of use, and for all other building products,
including concrete paving, per 0.09 m2 (1 ft2) of product over 50 years of use. The column labeled
"Total" is lie primary data cofu^^j^g io\^ ^Q~ ~^—~=^—^ ^-^^g|y]ng flow
amounts for each product component, followed by columns giving flow amounts for each life-
cycle stage. The product component columns sum to the total column, as do the life-cycle stage
columns. Tlie laindex column is for internal BEES use.
11 inn in nil i in iiiiiii i i i i i i i ii 11 i i n n i i nun i ii|iii MI n nl i i n i i : , i'."1* ,' i:,! I li'i'MBii'iKiJ^ "iiii'ii ;:;j|ii n
The economic performance data file LCCOSTS.DBF lists for each cost the year of occurrence
(counting from year 0) and amount (in 2000 dollars) per 0.76 m3 (1 yd3) for concrete products
124
-------
,Mote: lower values are halter'
sum
Qverall Performance.
au
Figure.4.8 Viewing BEES Overall Performance Results
Environmental Performance
G Siabal Wafrnlrig ;
I Nasuraf R
IB
11
tl
1?
'IT
Figure 4.9 Viewing BEES Environmental Performance Results
125
-------
ifiiti'ii'iii'iliiiii' ri.i fjiini-
Economic Performance
life/Glees
( '__, ^ ;
lr:Figure 4.10 Viewing BEES Economic Performance Results
!'! iji, >'<|, „ E\ * ifS , i • : l! i !H!! Iff ,nB:|iii:| liR-ilil "!l "UltlliiLiJII'iHi lllillBF :< nj'iilllillllliill i^ «3 'V" Si ii 'ii!'" HiiillHI'i1 ilinil'liilJIRiiiiiiliNff Hfi j|!;!i' iiliirii';"- 'Hi '•' 1 „": y'l"1'1!1"', lliillllKrliilhi IHliip: 'JiiiilJ'iJ1': illiFiiiiliiPKia "• ilH, I'lANi'iiiPipFillllPiliaiiBI!: vfl* '' 1 "nilllilllilil B!"!'iii' JlllilKIliill i /M' Jilllll!11 'lliw . '{' ii ft1 lilKIHIIi1'/ „; ,'ii!''!" ,«' '|! ''I1 <:,',' 1;' » " C::1!" '*• iliinl||ik«^^^^^ 'yiV' : ijn ,
126
-------
Global Warming by Life-Cycle Stage
1 fisw MaSef sals AtnaBitiuri
lUse
,
Linaeum •
PETltli^n
.5.. End of Life
373
17&3.
.Ltoetaum
117
1229
•41S
Figure 4.12 Viewing BEES Environmental Impact Category Performance Results by Life-
Cycle Stage
127
-------
ill I ill I nil) i (IIPiill II Illlilllll Illllll
IK (Illlilll II I ill Illllll I ill
(Illilll II I11
ii
Illllll l> lull1 II I N Illllll
111 III I III n Illllll
i n in n
111 111 I Illllll Illllll 11
Illlilllll I 11 Illllll
Acidification by Flow
g H+/unit
H £mmcn a
QHydroQenCiilarida
I Nitrogen Oxides
[ Sulfur Dsdes
I
3 D.40
0,00
Ltpolcum
Alternatives
Note: Lower values are better
Category
/Vnnrwoia
Hycfrogen Chloride
Hydrogen Ruorida
fferogori Qxldos
Suf uf Ojidea
Sum
Tile/Glass
0,0001
00019
CL0QD!
0.1251
0,3318
0.4590
Linoleum
'0. Ot344.
0,00®,
0.0008
•0.109&
0.1454
0.324S,
PETBrdlSjnrt
O.OODB
00052
0:0011
O.i767
0.1888
03723
figure 4.13 Viewing BEES Environmental Impact Category Performance Results
Contributing by Flow
i1 iKlll "I
128
-------
I tenrpnswsabte Energy
I Reresiabb Energy',
LU
1
•EmjpQdled Energy-by Fuel Renewability
Tii^Glass
Lindaum
Category
.:Nonrenesfffibie Energy
• Sum
TfWGlass
25.09,'
Linolftum
:21,45:
1.9
46:45
:
-------
Table 4.1 BEES Products Keyed to Environmental and Economic Performance Data Codes
Individual Element
Slab on Grade
Slab on Grade
Slab on Grade
Slab on Grade
Slab on Grade
Slab on Grade
Basement Walls
Basement Walls
Basement Walls
Basement Walls
Basement Walls
Basement Walls
Beams
Beams
Beams
Beams
Beams
Beams
Columns
Columns
Columns
Columns
Columns
Columns
Roof Sheathing
Roof Sheathing
Exterior Wall Finishes
Exterior Wall Finishes
Exterior Wall Finishes
Exterior Wall Finishes
Exterior Wall Finishes
Wall Insulation
Wall Insulation
Wall Insulating
Wall Insulation
Wall Insulation
Framing
Framing
Wall Sheathing
Wall Sheathing
Roof Coverings
Roof Coverings
Roof Coverings
Ceiling Insulation
Ceiling Insulation
Ceiling Insulation
Ceiling Insulation
Interior Wall Finishes
BEES Product
100 % Cement Content Concrete
15 % Fly Ash Content Concrete
20 % Fly Ash Content Concrete
20 % Slag Content Concrete
35 % Slag Content Concrete
50 % Slag Content Concrete
100 % Cement Content Concrete
15 % Fly Ash Content Concrete
20 % Fly Ash Content Concrete
20 % Slag Content Concrete
35 % Slag Content Concrete
50 % Slag Content Concrete
100 % Cement Content Concrete
15 % Fly Ash Content Concrete
20 % Fly Ash Content Concrete
20 % Slag Content Concrete
35 % Slag Content Concrete
50 % Slag Content Concrete
100 % Cement Content Concrete
15 % Fly Ash Content Concrete
20 % Fly Ash Content Concrete
20 % Slag Content Concrete
35 % Slag Content Concrete
50 % Slag Content Concrete
Oriented Strand Board
Plywood
Brick & Mortar
Stucco
Aluminum Siding
Cedar Siding
Vinyl Siding
R-l 3 Blown Cellulose
R-ll Fiberglass Batt
R-l 5 Fiberglass Bart
R-l 2 Blown Mineral Wool
R-l 3 Fiberglass Batt
Steel
Wood
Oriented Strand Board
Plywood
Asphalt Shingle
Clay Tile
Fiber Cement Shingle
R-30 Blown Cellulose
R-30 Fiberglass Batt
R-30 Blown Mineral Wool
R-30 Blown Fiberglass
Virgin Latex Paint
" "Number
fmpacts
6
6
6
6
6
6'
6 :
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
7
Environmental Data File
. ' • Name
A1030A
A1030B
A1030C
A1030D
A1030E
A1030F
A1030A
A1030B
A1030C
A1030D
A1030E
A1030F
A1030A
A1030B
A1030C
A1030D
A1030E
A1030F
A1030A
A1030B
A1030C
A1030D
A1030E
A1030F
B1020A
B1020B
B2011A
B201 IB
B2011C
B2011D
B2011E
B2012A
B2012B
B2012C
B2012D
B2012E
B2013A
B2013B
B1020A
B1020B
B3011A
B3011B
B3011C
B3012A
B3012B
B3012C
B3012D
C3012A
Economic Data
Code
A1030.AO
A1030,BO
A1030,CO
A1030,DO
A1030.EO
A1030FO
A2020,AO
A2020.BO
A2020.CO
A2020,DO
A2020,EO
A2020 FO
B1011,AO
B1011,BO
B1011,CO
B1011,DO
B1011,EO
B1011 FO
B1012,AO
B1012,BO
B1012,CO
B1012JDO
B1012,EO
B1012 FO
B1020,AO
B1020,BO
B2011,AO
B2011JBO
B2011.CO
B2011.DO
B2011 EO
B2012,AO
B2012,BO
B2012.CO
B2012,DO
B2012,EO
B2013,AO
B2013,BO
B2015,AO
B2015 BO
B3011,AO
B3011,BO
B3011 CO
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131
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Interior Wall Finishes
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Floor Coverings
Parking Lot Paving
Parking Lot Paving
Parking Lot Paving
Parking Lot Paving
Parking Lot Paving
Driveways
Driveways
Driveways
Driveways
Recycled Latex Paint
Ceramic Tile with Recycled Glass
Linoleum
Vinyl Composition Tile
Composite Marble Tile
Terrazzo
Nylon Carpet Tile w/Traditional Glue
Wool Carpet Tile w/Traditional Glue
Recycled Polyester Tile w/Traditional
Glue
Nylon Carpet Tile w/Low-VOC Glue
Wool Carpet Tile w/Low-VOC Glue
Recycled Polyester Tile w/Low-VOC
Glue
Nylon Broadloom Carpet w/Traditional
Glue
Wool Broadloom Carpet w/Traditional
Glue
Recycled Polyester Broadloom
w/Traditional Glue
Nylon Broadloom Carpet w/Low-VOC
Glue
Wool Broadloom Carpet w/Low-VOC
Glue
Recycled Polyester Broadloom Carpet
w/Low-VOC Glue
100 % Cement Content Concrete
15 % Fly Ash Content Concrete
20 % Fly Ash Content Concrete
Asphalt W/GSB88 Emulsified Sealer-
Binder Maintenance
Asphalt w/Cement Maintenance
100 % Cement Content Concrete
15 % Fly Ash Content Concrete
20 % Fly Ash Content Concrete
Asphalt w/Sealer Maintenance
7
6
10
10
6
6
6
6
6
6
6
6
6
6
6
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6
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C3020B
C3020C
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C3020E
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C3020H
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C3020J
C3020K
C3020L
C3020M
C3020N
C3020O
C3020P
C3020Q
G2022A
G2022B
G2022C
G2022D
G2022E
G2022A
G2022B
G2022C
G2031D
C3012,BO
C3020,AO
C3020.BO
C3020,CO
C3020,DO
C3020,EO
C3020.FO
C3020,GO
C3020,HO
C3020JO
C3020,JO
C3020,KO
C3020,LO
C3020,MO
C3020.NO
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ii! » -T '
150 years of use (except concrete paving), and cost (in 2000 dollars) per 0.09 m2 (1 ft2) for all
other products, including concrete paving over 50 years of use.
Warning: If you change any of the data in the environmental or economic performance data files,
you will need to reinstall BEES to restore the original BEES data.
II 1111 Ill
132
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5. Future Directions
Development of the BEES tool does not end with the release of version 2.0. Plans to expand and
refine BEES include releasing updates every 12 months to 18 months with model and software
enhancements as well as expanded product coverage. A BEES training program is also being
considered. Listed below are a number of directions for future research that have been proposed
in response to obvious needs and through feedback from the 1300 BEES 1.0 users:
Proposed Model Enhancements
• Combine building products to permit comparative analyses of entire building components,
assemblies, and ultimately entire buildings
• Based on input from homebuilders, residential designers, and product suppliers, tailor the
BEES tool to the residential sector (results of this effort may be disseminated as a separate
software tool)
• Conduct and apply research leading to the refinement of indoor air performance measurement
and to the inclusion of more environmental impacts for all BEES products, such as ecological
toxicity, human toxicity, ozone depletion, smog, and land use.
• Update the BEES LCA methodology in line with future advances in the evolving LCA field,
such as the anticipated development of national benchmarks for scoring environmental impacts
• Add a third performance measure to the overall performance score—product technical
performance
• Characterize uncertainty in the underlying environmental and cost data, and reflect this
uncertainty in BEES performance scores
Proposed Data Enhancements
• Solicit cooperation from industry to include, manufacturer-specific building products in BEES
version 3.0 (known as the "BEES Please" program)
• Add generic building products covering many more building elements, and add more products
to currently covered elements
• Refine all data to permit U.S. region-specific BEES analyses. This enhancement would yield
BEES results tailored to regional fuel mixes and labor and material markets, and would permit
inclusion of local environmental impacts such as locally scarce resources (e.g., water)
• Permit flexibility in study period length and in product specifications such as useful lives.
• Every five years, revisit products included in previous BEES releases for updates to their
environmental and cost data
• In support of the U.S. EPA Environmentally Preferable Purchasing Program, add key non-
building products to the BEES tool to assist the Federal procurement community in carrying
out the mandate of Executive Order 13101 (results of this effort may be disseminated as a
separate software tool)
Proposed Software Enhancements
• Add feature permitting users to easily enter their own environmental and cost data for BEES
analysis
• Add feature permitting integrated sensitivity analysis so that the effect on BEES results of
changes in parameter settings may be displayed on a single graph
133
-------
Ill 111 III I II III 111 III
111
111 111
LCPercentsij = —^—, where
134
Illlllllllll I PI ( II
i I
Appendix A. BEES Computational Algorithms
A.l Environmental Performance
BEES environmental performance scores are derived as follows.
EnvScore, = ) lAScorejk, where
JEinvScore, = environmental performance score for building product alternative j;
p = number of environmental impact categories;
lAScorejk = weighted", normalized impact assessment score for alternative j with
respect to environmental impact k:
IAik*IVwfc
lAScorejk = J * 100, where
Max{IAik, IA2k...IAmk}
I Vwtk = impact category importance weight for impact k;
m = number of product alternatives;
IAjk = raw impact assessment score for alternative j with respect to impact k:
n
IAjk = ^Lj * LAfacton, where
i - inventory flow;
n = number of inventory flows in impact category k;
Ig = inventory flow quantity for alternative j with respect to
flow i? from environmental performance data file (See section 4.4.);
lAfactorj = impact assessment factor for inventory flow i
The BEES life-cycle stage scores, LCScoreSJ, which are displayed on the environmental
performance by life-cycle stage graph, are derived as follows:
•ii i i i i in in in i nil 111 11 ii in mi i ii i ii • ^iSir** r i'iv'iv i'iifjiiif •! jfiE1''Siii.jM
inn i n 11 ii i in i i ill i nil 11 n iii ii in i i i i ^f'iiip '""J1 lf; ^'rStSli'^STI'SPtii'K'*'1'''" f <: '''lit''11''''!:'"''' '<"'"! iii!ll!^^
i = jT lAScorejk * IPercenty * LCPercentsij where
LCScoreg = life cycle stage score for alternative j with respect to stage s;
••_,_. Iy*IAfactori
IPercentu = —
lifulililillf 'IM
i "'f
-------
Isij = inventory flow quantity for alternative j with respect to flow i for life
cycle stage s;
r = number of life cycle stages
A.2 Economic Performance
BEES measures economic performance by computing the product life-cycle cost as follows:
, where
LCCj = total life-cycle cost in present value dollars for alternative j;
Q = sum of all relevant costs, less any positive cash flows, occurring in year t;
N = number of years in the study period;
d = discount rate used to adjust cash flows to present value
A.3 Overall Performance
The overall performance scores are derived as follows:
Scorej = [EnvWt * EnvScore,]-
EconWt*\
LCC,
,, LCC2 ,...,LCCn
'100
, where
Scorej = overall performance score for alternative j;
EnvWt, EconWt = environmental and economic performance weights, respectively
(EnvWt + EconWt==l);
n = number of alternatives;
EnvScorej = (see section A.I);
LCCj = (see section A.2); ,
135
-------
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*
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