POTEKTrAL FOR RED [JUNG CREEWKOIJSE CAS [E
rr\r TKIE Cor\^TR[JCT[or\r SECTOR
ectorStrategies
F(E[iR[JARY /
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FOR MORE INFORMATION
ABOUT THIS REPORT OR ERA'S SECTOR STRATEGIES PROGRAM
WITH THE CONSTRUCTION INDUSTRY, PLEASE CONTACT:
Peter Truitt
National Construction Sector Lead
U.S. Environmental Protection Agency (Mailcode 1807T)
1200 Pennsylvania Ave, NW
Washington, DC 20460
truitt.peter@epa.gov
February 2009
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"A RLE OF CO [
ACRONYMS AND ABBREVIATIONS n
INTRODUCTION 1
1 CHARACTERIZING THE CONSTRUCTION SECTOR'S GREENHOUSE GAS EMISSIONS 3
1.1 CHARACTERIZATION OF EMISSIONS 3
Breakdown of Emissions Sources 4
Comparing Emissions Estimates 5
Subsector Emissions 6
Emissions Intensity 7
1.2 PROJECTIONS OF THE FUTURE GREENHOUSE GAS IMPACTS OF CONSTRUCTION 9
2 EVALUATING OPPORTUNITIES TO REDUCE EMISSIONS 11
2.1 REDUCING FUEL USE 11
Reduced Idling 1 2
Equipment Maintenance 14
Driver Training 14
Properly Sized Equipment 1 5
Replaced or Repowered Equipment 15
Biofuels for Trucks and Nonroad Equipment 16
Alternatives to Diesel Generators 18
Employee Commuting 1 9
2.2 CONSERVING ELECTRICITY 20
2.3 REDUCING IMPACTS OF CONSTRUCTION MATERIALS 21
Recycling and Reuse 21
Materials Selection, Procurement, and Shipment Methods 24
3 CALCULATING COMPANY-SPECIFIC GREENHOUSE GAS EMISSIONS 26
3.1 EXISTING CALCULATION GUIDANCE 26
3.2 CURRENT APPROACHES IN CONSTRUCTION INDUSTRY INVENTORIES 27
3.3 CONSTRUCTION-SPECIFIC CALCULATION TOOL 28
4 SUMMARY 29
APPENDIX A: SUBSECTOR SIZE AND SOURCES OF EMISSIONS 31
APPENDIX B: DETAILS OF 2002 CONSTRUCTION SUBSECTOR EMISSIONS INTENSITY 34
APPENDIX C: CONSTRUCTION SUBSECTOR DESCRIPTIONS OF 2002 NAICS CODES 36
ENDNOTES 39
February 2009
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AEO Annual Energy Outlook
ANL Argonne National Laboratory
ASTM American Society for Testing and Materials
C&D Construction and demolition
CH4 Methane
CO2 Carbon dioxide
CO2e Carbon dioxide equivalents
DOE U.S. Department of Energy
EIA Energy Information Association
FLEET Freight Logistics Environmental and Energy Tracking
GDP Gross domestic product
GHG Greenhouse gas
HFC Hydrofluorocarbon
IPCC Intergovernmental Panel on Climate Change
ISO International Organization for Standardization
kWh Kilowatt-hour
MMT Million metric tons
Mpg Miles per gallon
N2O Nitrous oxide
NAICS North American Industry Classification System
PFC Perfluorocarbon
SF6 Sulfur hexafluoride
WBCSD World Business Council for Sustainable Development
WRI World Resources Institute
February 2009
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With growing attention to the impact of greenhouse gas (GHG) emissions on climate change, and in an
effort to better understand the construction industry's emissions, EPA's Sector Strategies Division has
developed this report on the sources and magnitude of construction GHG emissions and ways to reduce
them. Although numerous studies are available that help companies identify and quantify their GHG
emissions, none of them are specific to the construction industry. This document examines opportunities
explicitly for construction companies.
GHGs are necessary to life as we know it, because they keep the planet's surface warmer than it otherwise
would be. But, as the concentrations of these gases continue to increase in the atmosphere, the Earth's
temperature is climbing above past levels. According to NOAA and NASA data, the Earth's average
surface temperature has increased by about 1.2 to 1.4°F in the last 100 years. The eight warmest years on
record (since 1850) have all occurred since 1998, with the warmest year being 2005. Most of the warming
in recent decades is very likely the result of human activities. Other aspects of the climate are also
changing, such as rainfall patterns, snow and ice cover, and sea level.1
If greenhouse gases continue to increase, climate models predict that the average temperature at the
Earth's surface could increase from 3.2 to 7.2°F above 1990 levels by the end of this century. Scientists
are certain that human activities are changing the composition of the atmosphere, and that increasing the
concentration of greenhouse gases will change the planet's climate. But they are not sure by how much it
will change, at what rate it will change, or what the exact effects will be.2
The construction sector plays an essential role in improving the environment by continuing to improve the
environmental performance of the country's buildings and infrastructure. Because of its products'
longevity, the construction industry is in a unique position to support environmental benefits both through
everyday jobsite practices and through lasting structural improvements. Throughout this document, the
construction industry is defined as the national economic sector engaged in "the preparation of land and
the construction, alteration, and repair of buildings, structures, and other real property."3 This report's
definition of construction activities does not include activities prior to construction, such as design, siting
of buildings, or specification of materials, nor does it include the operation of structures following
construction.
The purpose of this report is not to suggest or propose GHG policies for the construction industry; this
paper does not recommend nor discuss any government actions to reduce emissions. Instead, the
information presented represents an overview of current knowledge on the sources of construction GHG
emissions. The opportunities to reduce emissions presented within this document are meant to illustrate
possible approaches to GHG reductions, based on the best available information. Topics such as biofuels
and materials recycling have been included to better address the GHG implications of increasingly
popular "green construction" practices.
Characterizing the GHG emissions of the construction sector presents challenges, most notably due to the
large number of firms (estimated at more than 800,000) and the even larger number of construction sites
where the majority of emissions occur.4 Limited data are available to accurately estimate collective,
sector-wide emissions from the hundreds of thousands of construction firms. The estimates that are
available are presented in Section 1, which also highlights key assumptions made in the calculations. In
addition to total emissions, an overview of emissions intensity (emissions per dollar value added)
provides another metric to assess the construction sector's impact compared with those of other industrial
February 2009 1
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sectors. Both emissions and emissions intensity are characterized for the three major subsectors:
Buildings, Heavy and Civil Engineering, and Specialty Trades.
If a large number of small GHG emissions sources within the construction industry were to adopt energy-
and climate-conscious practices, aggregate emissions could be reduced substantially. Opportunities for
reducing emissions are presented in Section 2, including practical and low-cost changes in operations.
Consistency and clarity in calculating emissions are important in order to compare emissions within and
across sectors, and for companies to plan and assess progress. Section 3 presents information on GHG
inventory protocols that are publicly available and frequently used, and examines the attributes of a
protocol that would be useful for companies in the construction sector.
February 2009
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CHARACTERING THE CONSTRUCTOR
GREENHOUSE GAS BOSTONS
In 2002, the construction industry produced approximately 1.7% of total U.S. greenhouse gas emissions.
Equivalent to 6% of total U.S. industrial-related greenhouse gas emissions, this quantity places
construction as one of the top emitting sectors.5 Although construction practices typically do not produce
large quantities of GHGs compared to the operations of many other sectors, the sheer number of
construction projects results in significant aggregate emissions for the sector.
To provide a better understanding of the sector's GHG emissions, Section 1 discusses the data and
methods used to calculate the tons of GHG emissions for the sector. Current emissions accounting
includes only traditionally quantified emissions sources: fossil fuel combustion and purchased electricity.
Future accounting may include lifecycle emissions, such as emissions from the production and transport
of the materials used or waste disposed, which would provide a more complete estimate of the impact of
construction activities.
In addition to the measure of the tons of GHGs emitted, "emissions intensity" (emissions per dollar of
value added) provides another metric of environmental performance that also takes into account economic
performance. Emissions intensity may be useful to identify sectors or subsectors with highly emissive
processes. To meaningfully interpret the emissions intensities of construction subsectors requires prior
knowledge of the factors and processes that affect both emissions and value added.
T,' Cr-fARAcriERrzATroFJ OF EitfrssroFJS
The Sector Strategies Division of EPA recently released the report Quantifying Greenhouse Gas
Emissions in Key Industrial Sectors in the U.S., which presents historical emissions estimates for 14
industrial sectors that produce 84% of industrial GHG emissions in the United States. According to this
report, the construction sector produced 6% of total U.S. industrial GHG emissions in 2002.6 As shown
in Figure 1, the construction sector has the third highest GHG emissions among the industrial sectors
analyzed. In this figure, GHG emissions are grouped by three broad categories of activities: fossil fuel
combustion, purchased electricity, and non-combustion activities. Fossil fuel combustion is the use of
fossil fuels, such as gasoline, diesel, or coal, to produce heat or run equipment. Purchased electricity is
the quantity of GHGs resulting from the generation of purchased electric power. Non-combustion
activities include the production of GHGs from other processes or reactions, such as when CO2 is released
during the calcination stage of lime production.
February 2009
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Figure 1: 2002 Greenhouse Gas Emissions from Key Industrial Sectors
Oil and Gas
Chemicals
Constructor
Forest Products
Iron snd S:eel
Food ar d Bev erages
Mir ig
Cement
Alumina and Aluminum
Plastic and Rubber Products
Tex dies
Lime
Metal Casting
Semiconductors
Mon-combustion
Fossil Fuel Combustion
Purchased Electricity
41"'
500
MMTCO2e
Notes: Depending on the sector, emissions may include CO2, methane (CH4), and nitrous oxide (N2O). For construction, only
CO2 emissions are reported for fossil fuel combustion.
MMTCO2e = million metric tons of CO2 equivalents.
Source: Reprinted from U.S. EPA, Quantifying Greenhouse Gas Emissions in Key Industrial Sectors in the U.S., Sector
Strategies Division, May 2008, Figure 1-4.
For the construction industry, the two major sources of emissions included in the Quantifying Greenhouse
Gas Emissions in Key Industrial Sectors report relate to fossil fuel combustion, primarily from
construction equipment, and fuel use from purchased electricity. The report estimated that in 2002 the
construction sector released 131 million metric tons of CO2 equivalents, as shown in Table 1.
Table 1 :
Construction Sector Greenhouse Gas Emissions, 2002
Emissions source
Fossil Fuel Combustion
Purchased Electricity
Total
Million metric tons of CO2e
100
31
131
Percent of total
76%
24%
Source: U.S. EPA, Quantifying Greenhouse Gas Emissions in Key Industrial Sectors in the U.S., Sector Strategies Division,
May 2008.
Note: Fossil fuel combustion is an estimate of CO2 emissions only. Purchased electricity is an estimate of CO2, CH4, and N2O
emissions. To remain consistent with the source report cited above, the total quantity is presented in units of CO2e.
February 2009
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FOSSIL FUEL COMBUSTION — For 2002, the Quantifying Greenhouse Gas Emissions in Key Industrial
Sectors report estimated that the construction sector released 100 million metric tons of CO2 from fossil
fuel combustion. This estimate was derived using the 2002 Economic Census data of the dollars the sector
spent on fuel purchases, divided by the average 2002 cost per gallon of diesel and gasoline from EIA's
State Energy Data Report to calculate the gallons of fuel purchased. Gallons were then converted to CO2
emissions using EPA emissions factors for mobile combustion fuels. Fossil fuel combustion includes
emissions from on- and off-highway construction vehicle combustion of gasoline and diesel fuel, natural
gas combustion for office power, heating and tools, and diesel used for generators. Gasoline and diesel
fuel combustion accounted for approximately 88 million metric tons of CO2, and consumption of natural
gas accounted for approximately 12 million metric tons. The data sources used to calculate the emissions
do not provide information on gasoline and diesel consumption separately. Therefore, the report used the
following assumptions: 50% of on-highway construction vehicles use diesel and 50% use gasoline, and
all off-highway vehicles consume only diesel fuel. The emissions calculation does not take into account
emissions of N2O or CH^, which can vary by vehicle emissions control technologies. These additional
GHG emissions could be significant for older heavy-duty equipment without recent emissions control
technologies.7
PURCHASED ELECTRICITY — The Quantifying Greenhouse Gas Emissions in Key Industrial Sectors
report estimated that the electricity that the construction sector purchased resulted in the release of 3 1
million metric tons of CO2 equivalents in 2002. Emissions from purchased electricity result from fuel
combusted at the power plant. The report calculated these emissions from sector-reported electricity
purchases, using an average national emissions factor for 2004 from EPA's eGRID model of electricity
sources.8
In addition to the emissions estimate of 13 1 million metric tons of CO2e from construction sector fuel
combustion and purchased electricity presented in the Quantifying Greenhouse Gas Emissions in Key
Industrial Sectors report, two other sources provide estimates of the sector's GHG emissions:
• The Energy Information Association (EIA) of DOE produces an analysis of CO2 emissions
from the construction sector as a supplement to its Annual Energy Outlook (AEO). For 2002,
AEO 2008 estimated construction sector emissions from fossil fuel combustion and purchased
electricity as 77.4 million metric tons of CO2. The AEO 2008 produces estimates as model
output of the EIA National Energy Modeling System's Industrial Sector Demand module,
based on multiple inputs.9
• EPA calculates GHG emissions from the construction sector for its annual Inventory of U.S.
Greenhouse Gas Emissions and Sinks. The most recent Inventory estimated CO2 emissions
from the construction and mining sectors in 2002 as 57.9 million metric tons of CO2 for non-
transportation mobile sources (i.e., sources that do not move people or goods) only. These
estimates were developed from EPA's NONROAD model and FHWA's Highway Statistics.
Direct comparisons of the different emissions estimates are complicated by the widely-varying methods
they use to estimate emissions. The Quantifying Greenhouse Gas Emissions in Key Industrial Sectors
report used data on the dollars spent on electricity and fuel, which were converted to physical units based
on national average purchase prices. The AEO and EPA Inventory methods use multiple inputs and each
uses a different model to estimate emissions. The EPA Inventory estimate is less comparable in that it
includes only non-transportation mobile sources, and presents construction and mining emissions as one
February 2009 5
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aggregated value. The estimates of emissions reductions presented in Section 2 of this report are based on
the values and methods from Quantifying Greenhouse Gas Emissions in Key Industrial Sectors.
The 2002 Economic Census Industry Series reports fuel consumption and purchased electricity by
subsector; therefore, emissions can be attributed to each of the construction subsectors defined by the
North American Industry Classification System (NAICS).10 Following the method of the Quantifying
Greenhouse Gas Emissions in Key Industrial Sectors report, the estimated emissions for the construction
subsectors are shown in the pie chart in Figure 2. As noted in Table 1, the method used to estimate
emissions combines CO2 emissions only for fossil fuel combustion, and CO2e emissions for purchased
electricity. The totals are presented in Figure 2 as CO2e to be consistent with the source document. Also
note that approximately 97% of the total CO2e emissions from fossil fuel combustion are attributable to
CO2.11 Subsectors in Figure 2 are defined at the five-digit NAICS level. With the exception of Industrial
Building Construction, subsectors that contribute 5% or less of the total industry emissions are included
in the "Other subsectors" categories.
Figure 2: Construction Industry Subsector Emissions in 2002
Construction Industry Emissions, by Subsector
(% by CO2e)
Other subsectors,
Specialty Trade -,
Contractors, 23.9% \ /^^
m
Site preparation
contractors, 6.2% ^H ^_^^-^
V — >^^ ^^H
Residential building
construction , 18.4%
\ Industrial building
\^ construction, 1.3%
^
-------
For context, Table 2 presents the proportion of the sector's establishments in each of the three major
subsectors, along with the contribution of each subsector to total construction GHG emissions. To better
understand subsector emissions, it is important to consider whether the driving cause of emissions is a
subsector's emissions-producing activities or its size. Appendix A provides a table of the more detailed
subsectors, with the associated emissions by source (i.e., purchased electricity, natural gas consumption,
or on-highway and off-highway vehicle fuel use) and the number of establishments. Emissions intensity,
presented in more detail in the following section, provides a metric to view the subsector's emissions in
the context of its relative economic size.
Emissions intensity provides a means for comparing sectors' emissions while taking into account
economic output. Emissions intensity is typically calculated as a ratio of the GHG emissions produced per
dollar of gross domestic product (GDP). In portraying industry-specific emissions intensity, the most
analogous measure to GDP is the value added by the industry. The 2002 Economic Census provides
information on the value added by the construction industry and its subsectors.
Figure 3: Emissions Intensities for Key Industrial Sectors, in metric tons CO2e/2002k$
Comparison of Industrial Sector Emissions Intensities
100
2002 GHG Emissions (MMTCO2e)
200 300 400
500
600
Oil and Gas
Chemicals
Construction
Forest Products
Iron and Steel
Food and Beverages
Mining
Cement
Aluminum
Plastic and Rubber Products
Textiles
Lime
Metal Casting
Semiconductor
I 3.53
1.46
| 0.23
J0.85
]0.45
12.91
' 16.'
30-48 |
JO^
3J1.14
J~|0.28
29
4
• Emissions
• Intensity
I 42.5
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00
Emissions Intensity (MTCO2e/thousand 2002$)
40.00
45.00
Note: MTCO2e = metric tons of CO2 equivalents; MMTCO2e= million metric tons CO2 equivalents.
Source: Emissions values used in the emissions intensity calculations for 2002 from the Quantifying Greenhouse Gas Emissions in
Key Industrial Sectors in the U.S. EPA report (May 2008). Value added for emissions intensity calculations taken from the 2002
Economic Census Industry Series reports, aggregated by sector by the method defined for emissions estimates in the Quantifying
Greenhouse Gas Emissions in Key Industrial Sectors in the U.S. EPA report. Construction industry value added compiled from
subsector 2002 Economic Census Industry Series reports, Table 4.
February 2009
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Figure 3 presents emissions intensities for the industries identified in the Quantifying Greenhouse Gas
Emissions in Key Industrial Sectors report, in order of decreasing absolute emissions (shown in the same
order as Figure 1). In comparison to other industrial sectors identified in this report, the construction
industry had the lowest 2002 emissions intensity at 0.23 metric tons of CO2 equivalents per thousand
2002 dollar (MTCO2e/2002k$), and the lime and cement sectors had the highest intensities at 42.5 and
18.2 MTCO2e/2002k$, respectively.
Figure 4 compares emissions intensities among construction subsectors as defined by five-digit NAICS
codes. The variety of processes within the construction sector leads to significantly different emissions
intensities across subsectors, as shown in Figure 4 and Appendix B. For example, the highway, street, and
bridge construction subsector (NAICS code 23731) has a much higher emissions intensity than power and
communication line construction (NAICS code 23713). Value added for the highway, street, and bridge
construction subsector is 1.6 times greater than for the power and communication line construction
subsector, yet emissions by highway, street, and bridge construction are more than five times those of the
power and communication line construction.
Figure 4: Construction Industry Emissions Intensity, with Breakdown by Subsector, in
MTCO e/2002k$
Construction Emissions Intensity, by Subsector
CM
O
o
C!
0.60
0.50
NAICS 236: NAICS 237: Heavy and Civil
Construction Engineering Construction
of Buildings*
O
in
I
in
c
o
in
in
E
LU
NAICS 238: Specialty Contractors
0.00 4J-
y
^j^y
o°N o°N
<<> ^
-------
Table 3: Top and Bottom Five Construction Subsector Emissions Intensities,
by Five-Digit NAICS Code
u>
Q.
£
Bottom 5
2002
NAICS
23731
23899
23711
23799
23891
23829
23713
23813
23822
23831
Subsector Description
Highway, street, and bridge construction
All other specialty trade contractors
Water and sewer line and related structures construction
Other heavy and civil engineering construction
Site preparation contractors
Other building equipment contractors
Power and communication line and related structures construction
Framing contractors: Carpentry
Plumbing, heating, and air conditioning contractors
Drywall and insulation contractors
Intensity
(MTC02e/2002k$)
0.49
0.41
0.37
0.37
0.36
0.17
0.14
0.13
0.10
0.03
In summary, differences in an industry's emissions intensity may result from any or all of the following
factors: the amount of energy used, the fuel mix used, the size and number of firms, or the economic
production of the sector. Overtime, decreasing emissions intensity may indicate decreasing energy use in
the sector, but it may instead indicate increasing economic production. Therefore, emissions intensity is
not sufficient to identify or compare any reductions in emissions unless combined with an understanding
of the subsector's absolute emissions and the value added.
ECTOR OR TKR RJTLTRR GRRRWKOLTSR GAS [MFACTS OR
EIA's Annual Energy Outlook provides annual projections of U.S. energy supply and demand to the year
2030. As part of its analysis of industrial sectors, the AEO provides annual estimates of CO2 emissions
from the construction industry's fossil fuel combustion and purchased electricity. To produce the AEO
projections, economic factors and technology predictions are provided to an integrated economic model,
which in turn produces estimates of energy consumption based on the sources' related economic impacts.
As a result, both energy consumption and emissions are derived from corresponding economic factors.
According to the recent AEO 2008, the construction sector and its CO2 emissions are particularly affected
by the recent slowdown in the U.S. economy in the near term.12
The sector's long-term energy consumption is not expected to grow significantly, even when the sector's
growth resumes, due to expected advances in technology and changes in fuel use, including increased use
of biofuels and renewable energy to generate electric power. By 2030 construction energy is not expected
to surpass historic levels of consumption. Figure 5 shows that aggregate construction CO2 emissions are
expected to decline slightly from 2005 levels by 2030. Economic projections show that construction value
added will increase much more significantly than emissions, suggesting an overall decrease in emissions
intensity.
February 2009
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FigureS: Projection of Construction Industry CO Estimates to 2030
Projection of Construction Industry Emissions to 2030
V)
c S
° o
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7- EVALUATING OppopTur\rrnE5 TO REDUCE
Construction contractors may have control over many of the activities associated with GHG emissions at
a construction site, such as how efficiently they use fuel and electricity. However, other decisions that
result in GHG emissions (e.g., materials selection and site selection) are usually made by project owners
and architects, not by contractors. The following table lists the construction activities that result in GHG
emissions, and categorizes each activity by contractors' potential ability to affect emissions.
Figure 6
: Contractors' Influence on Activities Resulting in GHG Emissions
Most Influence
Fuel selection
Equipment maintenance
Equipment idling
Equipment selection
Some Influence Possible
Materials selection
Materials shipment
Electricity use
Materials recycling
1
Employee commuting
Vegetation removal
Little Influence
Site selection
Structure design and
performance
This section examines options for reducing greenhouse gas emissions associated with construction
activities, focusing on the activities that construction companies control or influence. The options and
scenarios presented in this section are based on currently available technologies and techniques, where
emissions reduction can be realized in the near term. In the long term, future changes in available
technologies and fuels will likely result in additional or different options. In Sections 2.1 and 2.2, we
present options for reducing GHG emissions through reductions in fuel and electricity consumption,
where the most direct and measurable emissions reductions can be realized. Recent focus has also turned
to considering the emissions related to the entire construction supply chain from a lifecycle perspective.
In Section 2.3, we present emissions reduction options related to the construction lifecycle, such as
materials reuse and recycling. We present the emissions and costs associated with each option, when
these are available. In most cases, the emissions reductions and costs are rough estimates, included to
provide the general magnitude of emissions reductions possible. Unfortunately, the quantitative
information needed for more-precise estimates is not currently available.
Estimates presented in Section 1 indicate that approximately three-quarters of the GHG emissions from
the construction sector result from diesel, gasoline, and natural gas combustion. The GHG reduction
options presented in this section focus on reducing the emissions from fuel combustion, primarily by
improving fuel efficiency. Better fuel efficiency results in less fuel consumed to complete the same job,
thereby reducing emissions as well as fuel costs. Often, the steps taken to improve fuel efficiency also
result in other benefits, including increased equipment life and reduced emissions of other air pollutants
such as particulate matter. Historically, fuel costs have not constituted a large portion of construction
firms' operating budgets15, and thus many contractors have not focused on reducing their fuel use. Fuel
February 2009
11
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costs are rising, however, and with increased costs, fuel efficiency is expected to become a higher priority
for construction contractors. As contractors implement techniques to reduce their fuel costs, they will
simultaneously reduce their GHG emissions.
Table 4 presents CO2 emissions factors for the fuels most commonly used in the construction sector. The
emission factor for diesel fuel indicates that 22.37 Ibs of CO2 are emitted for every gallon of diesel
combusted, and 19.54 Ibs of CO2 are emitted for one gallon of gasoline. The last two columns in the table
present the estimated tons of CO2 emissions that could be reduced in the United States if the construction
sector reduced use of the fuel by 3% or by 10%. These percent values were selected as a practical way to
illustrate the magnitude of emissions reductions associated with the two different levels of improvements,
and are used throughout this section of the report. For example, if the construction sector as a whole
reduced diesel fuel use by 10%, the reduction in CO2 emissions would be an estimated 14.8 billion Ibs
(6.73 million metric tons) of CO2. A 10% reduction in diesel fuel use would reduce construction sector
CO2 emissions from all energy sources by approximately 5%.
Table 4: GHG Emissions Reduction Scenarios from Reduced Fossil Fuel Use
Fuel
Diesel
Gasoline
Propane
Natural gas
Emissions
(Ibs CO2/unit
material)
22.37 Ibs CO2/gallon
19.54 Ibs CO2/gallon
12.66 Ibs CO2/gallon
11.7lbsCO2/1,OOOft3
Estimate of Sector-Wide Emissions
Reductions*
Using 3% less fuel
4,455 million Ibs CO2
2.02 MMTCO2
1,383 million Ibs CO2
0.63 MMTCO2
NA**
786 million Ibs CO2
0.36 MMTCO2
Using 10% less fuel
14,849 million Ibs CO2
6.73 MMTCO2
4,609 million Ibs CO2
2.09 MMTCO2
NA**
2,620 million Ibs CO2
1.19MMTCO2
Notes: Emissions factor for diesel and gasoline converted from EPA's 2008 Inventory of Greenhouse Gases 1999-2006,
Table A-29 and A-30. Emissions factor for propane and natural gas converted from EIA data sources.
MMTCO2 = million metric tons of CO2
* Estimate of possible emissions savings from percentage reductions, based on the 2002 fuel consumption estimates
and assumptions used in the EPA report, Quantifying Greenhouse Gas Emissions in Key Industrial Sectors in the U.S.
(May 2008). Numbers presented are for the purpose of illustrating the magnitude of possible reductions only and should
not be interpreted as absolute quantities. No Economic Census data are available to estimate sector-wide propane
consumption.
** NA = Data not available.
To achieve improvements in fuel efficiency and realize the associated reductions in GHG emissions,
contractors can make changes ranging from reducing equipment idling time and improving maintenance
to replacing or repowering equipment. Information on these and other options follows.
REDUCED [DUWC
Unnecessary idling occurs when trucks wait for extended periods of time to load or unload, or when
equipment that is not being used is left on, such as to maintain heating or cooling for driver comfort.
Reduced idling reduces fuel consumption and the associated costs and GHG emissions. Regulations
restricting idling were in place in almost half the states as of July 2008. These regulations vary by state,
county, or city, but typically restrict idling to 3-10 minutes and do not distinguish between gasoline or
diesel vehicles.16 Most of these regulations are relatively new, and many have associated information
February 2009
12
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campaigns to increase awareness of the fuel costs and emissions caused by idling. Idling reductions can
also reduce longer-term costs; each hour of idling eliminated can save as much as 2 hours of engine life.
Since an idling engine does not generate enough heat for proper combustion, deposits will form over time
on the piston and cylinder walls and contaminate the oil. This contamination creates additional friction
that will accelerate engine wear.17
To reduce idling and the associated GHG emissions, construction firms need to evaluate when and why
idling occurs in the company's activities; this evaluation may include reviewing fuel receipts to
understand which projects or groups are consuming more fuel, interviewing drivers, or making systematic
observations of the work site. Idling reductions can be achieved through changes in work practices, such
as training drivers to turn off equipment rather than idle, or through changes in equipment, such as adding
fuel-efficient auxiliary power for the heat or air conditioning needed for driver comfort.
GHG Emissions Impacts: No data were identified that estimate the average GHG emissions
associated with construction equipment idling, or the national average idle time for a piece of
construction equipment. Some targeted studies, however, provide some information that can be
used to assess emissions from idling construction equipment and vehicles. A study of long-haul
truck idling indicates that GHG emissions depend upon the level of idling and on how often the
idling occurs. A typical Class 8 diesel engine at high idle consumes 1.2 gallons of fuel per hour,
which translates to 26.1 Ibs CO2 emissions per hour. At low idle, 0.6 gallons are consumed per
hour, resulting in 12.8 Ibs CO2 emissions per hour.18 A 2005 study of California construction
equipment shows that an average heavy-heavy duty diesel truck (Class 7) idles 29.4% of its
operational time.19 An analysis by one construction firm of all its construction equipment (over
300 pieces) estimated that an idling reduction equal to 10% of the total operating time would save
almost 524,660 Ibs (238 metric tons) CO2 per year, using the assumption that idling consumes 1.2
gallons fuel per hour.20
Without data on the total idling hours for construction vehicles and equipment in the United
States, the total potential emissions reductions possible through sector-wide idling reductions
could not be estimated. As an illustrative example of the potential sector-wide impact of idling
reductions on GHG emissions, we examine two scenarios:
• If construction firms could reduce idling by an average of 10 hours per month per firm
(be it a reduction of 10 hours/month from one piece of equipment or a 1 hour/month
reduction from 10 pieces of equipment), the resulting GHG emissions savings sector-
wide would total approximately 1.4 billion Ibs of CO2 (650,000 metric tons) per year.21
For purposes of illustration, this scenario intentionally presents a simplified calculation
where it is assumed that on average, each construction firm reduces idling by 10 hours
per month. From a practical standpoint, we acknowledge that for some firms, such as
those that do not own heavy equipment, 10 hours/month idling reduction is not feasible.
Other firms that regularly operate many pieces of equipment, however, may be able to
reduce idling by more than 10 hours per month; thus, we rely on the averaging across
different types of firms to establish this estimate.
• If construction firms could reduce idling of off-road diesel equipment by 10%, the
resulting GHG emissions savings sector-wide could total approximately 1.8 billion Ibs of
CO2 (830,000 metric tons) per year. This estimate is limited in that it includes off-road
vehicles only, and makes the following assumptions based on minimal available data: the
sector operates 2 million off-road vehicles at 1,500 hours per year, and idling emits 20.7
Ibs CO2 per hour.22
February 2009 13
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Cost Impacts: Argonne National Laboratory (ANL) provides a simple worksheet to calculate
savings from reduced idling.23 For technology solutions to idling, the ANL worksheet may help
construction firms to calculate the payback period for various products. For many construction
firms, reducing idling would involve changing work practices. While implementing an idling
reduction program requires staff time to raise awareness of and monitor new work practices, the
external costs are minimal.
[Eoj;[pr\/iFJ\n~ \\r\ A [
Proper maintenance often results in fuel savings, although the magnitude of savings varies by equipment
type and condition. Maintenance may include systematic equipment inspection, detection of potential
failure, and prompt correction. Two examples of maintenance activities that can reduce GHG emissions
include:
Q Forklift maintenance. A recent study of forklift maintenance estimated that 50% of forklifts were
not properly maintained, each of which could be wasting more than 400 gallons of propane
annually.24
GHG Emissions Impacts: Propane emits about 12.7 Ibs of CO2 per gallon, resulting in more than
2.3 tons of CO2 emitted by each improperly maintained forklift each year.
Cost Impacts: At the average 2007 propane price of $1 .87 per gallon, 400 gallons wasted costs
about $750 per year.
Q Improperly inflated tires and poor wheel alignment, which can adversely affect fuel efficiency of
a small truck by 3-4%. Under-inflated tires increase the tires' rolling resistance, and increased
rolling resistance requires more fuel to move the vehicle.
GHG Emissions Impacts: A 3-4% improvement in fuel efficiency can reduce CO2 emissions per
vehicle by 650-860 Ibs (0.3 to 0.4 metric tons of CO2) annually for a typical light-duty diesel
truck.25
Cost Impacts: At the 2007 U.S. national average cost of diesel sold to industry of $2.34 per
gallon, the above losses may save the operator up to $90 in fuel costs per vehicle.26
pp[VF-R TPAMKTr
Driver training can also provide incremental savings by more efficiently operating equipment.
Q Komatsu estimates that excavator operators who needlessly shift hydraulic levers while already at
the equipment's maximum capacity in futile attempts to lift more could save a company 225
gallons of fuel per year if this practice were eliminated for even 1 hour a day. 2?
GHG Emissions Impacts: Assuming a generic emissions factor of 22.37 Ibs of CO2 per gallon,
such reductions could save 5,033 Ibs (2.28 metric tons) CO2 per year.
Cost Impacts: At the 2007 U.S. national average cost of diesel fuel ($2.34 per gallon for regular
diesel), the above fuel savings from a 1-hour per day reduction could reduce costs by $527 per
year for each excavator. 28
February 2009 14
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Q Reducing the angle at which an off-road truck is parked next to a loading excavator can save fuel.
Having the excavator's boom swivel 30 degrees to dump its load instead of 90 degrees could
reduce fuel use for the task by 3%. 29
GHG Emissions Impacts: A large excavator may use up to 20 gallons fuel per hour, resulting in
GHG emissions up to 440 Ibs per hour. A 3% improvement in fuel efficiency could reduce
emissions by up to 13 Ibs for each hour the loading angle is improved.
Cost Impacts: At the 2007 U.S. national average cost of diesel, a change of 3% could provide
more than $1.40 in fuel savings for each hour the loading angle is corrected.
Q Excavating a slope in two stages in a stair fashion, instead of dragging a bucket from bottom to
top in one motion, shortens the cycle between dumps and uses 8% less fuel, according to
Komatsu engineers.30
GHG Emissions Impacts: GHG emissions and cost impacts which will vary depending on the
parameters of each excavation task. For a large excavator using 20 gallons fuel per hour, an 8%
improvement in fuel efficiency could reduce emissions by up to 35 Ibs for each hour that stair
fashion excavating is used in place of the bottom to top dragging technique.
Cost Impacts: At the 2007 U.S. national average cost of diesel, a change in fuel efficiency of 8%
could provide $3.75 in fuel savings for each hour the improved excavating technique is used.
RPWERLY SfZED [EcjjrFr\/iErn~
Identifying the proper size equipment for a task can also provide fuel savings and associated reductions in
GHG emissions. Truck engines too large for an application burn more fuel by adding unnecessary weight.
In addition, drivers may be prone to use the excess horsepower needlessly, causing additional fuel
consumption. An undersized engine easily becomes overworked, leading to excess fuel consumption and
accelerated engine wear.31 Possible GHG emissions reductions are proportional to the difference between
the horsepower used and the horsepower required for the task. The potential emissions savings are also
firm-specific, in that the proper size equipment may not be available in the company's fleet. Given the
scope of these constraints, a reasonable illustrative example of the possible GHG reductions resulting
from proper sizing of equipment could not be developed.
REPLACED op REFOWEPEE EojirpiviEK'T
Longer-term fuel-saving solutions involve replacing older, less fuel-efficient equipment with newer
models. Through advances in engine technology, reduced equipment weight, and even some hybrid
technologies, equipment manufacturers are offering more fuel-efficient new equipment.
Installation of hydraulic fans as part of repowering can reduce fuel consumption and the associated
emissions. Hydraulic fans operate with variable speed to optimize engine cooling when needed, unlike
belt-driven fans where the air flow is dependent on the engine speed, not on the cooling demand. Less
power is then required for cooling, and the lowest amount of fuel per horsepower is consumed when the
engine is operating consistently at optimal temperature.32
Replacement engine systems show promise in reducing fuel consumption and emissions by new
technologies. Through repowering with a new diesel engine, an older piece of equipment is brought up to
the fuel economy, emissions, and maintenance standards of new equipment, thus reducing overall
equipment operating costs. The potential for emissions reductions will be based on the age of the engine
February 2009 15
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replaced and the differences in technology. While a firm is not likely to replace or repower its entire fleet,
these options are meant as suggestions for additional ways to achieve emissions reductions if faced with
malfunctioning older equipment.
GHG Emissions Impacts: Manufacturers have reported that new engines can improve fuel
economy by 5% or more.33 A 2008 article cited that replacing a 1995 tractor hauler engine with a
2009 model increased fuel economy from 4.6 mpg to 6.2 mpg, an improvement of almost 35%.34
By improving fuel efficiency by 5%, a track-type tractor operating 1,500 hours per year and
typically using 16 gallons of fuel per hour could reduce its emissions by 26,800 Ibs (12 tons) CO2
per year.35
Cost Impacts: The cost of repowering a piece of equipment is high and depends on the age,
make, and model of the machine. For example, the cost of repowering a single engine scraper
may be as much as $ 120,000.36 The likely benefits depend on the equipment replaced.37 For the
example above, assuming 2007 national average industry diesel costs, a 5% improvement in fuel
economy would save an owner $2,800 per year in fuel costs.
[ifCprJELS FOR TRUCKS AMD ROMRO/D fiOJJrRMF-MT
Using low-carbon fuels in place of petroleum gasoline or diesel also reduces GHG emissions. In
particular, the growth of the biofuel industry may allow opportunities to reduce emissions, although the
resulting lifecycle emissions benefits are under debate. Lifecycle emissions calculations are largely
dependent on the source material, its growth process, and the fuel type used at biofuel refineries. Biofuels
that require significant fertilizer applications or refining release more GHGs through additional
processing, and fossil fuel combustion at refineries displaces some of the emissions benefit of using the
biofuel. In the United States, approximately 89% of biodiesel is currently derived from soybeans, with
less than 9% of production from recycled vegetable oils or tallow.38 To control biodiesel quality,
standards of the American Society for Testing and Materials (ASTM) require biodiesel sold in the United
States to be derived only from virgin vegetable oils or animal fats.39
The most recent compilation of scientific literature on biofuel lifecycle emissions, the Gallagher Review
of the Indirect Effects of Biofuels Production, presents biodiesel emissions savings ranges for various
biofuels, when compared to fossil fuels (see Figure 7).40 For example, switching from petroleum diesel to
biodiesel from palm oil will reduce GHG emissions by approximately 25% - 65%, depending on the type
of fuel used at the biofuel refinery (e.g., renewable energy or petroleum), for technologies in use globally
as of 2008. These results suggest that switching from petroleum diesel to 100% biodiesel (B100) may
reduce GHG lifecycle emissions by more than 80% or may increase emissions by almost 20%; on
average, without considering land-use changes associated with crop production, biodiesel from soybeans
may provide an emissions savings of 33%.41 The Gallagher Review also suggests that the current
uncertainty in total GHG emissions changes may be even greater than the range shown above as a result
of variability in calculating emissions from land-use shifts due to increased biofuel feedstock growth.42
According to the foremost U.S. study published in 1998 by the U.S. Department of Energy, biodiesel
from soybean oil is estimated to reduce lifecycle CO2 emissions by 78% when compared to petroleum
diesel.43 The lifecycle emissions are proportional to any blending with petroleum, so a 20% biodiesel
blend (B20) may achieve approximately a 16% reduction in lifecycle CO2 emissions.
February 2009 16
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Figure 7: Range of Possible GHG Emissions Savings for Various Biofuels
Source: Reprinted from the Renewable Fuels Agency, The Gallagher Review of the Indirect Effects of Biofuels Production,
July 2008, http://www.dft.gov.uk/rfa/ db/ documents/Report of the Gallagher review.pdf.
The use of biodiesel has additional caveats that should be considered before converting equipment.
Biodiesel has different solvent properties from petroleum diesel. Biodiesel will degrade any engine hoses
or gaskets made with natural rubber (generally used on vehicles manufactured prior to 1992), and will
break down any residual petroleum deposits in fuel lines, which in turn will clog fuel filters. As a result,
use of biodiesel may void a vehicle's warranty without proper maintenance and dealer approval for fuel
switching. Nevertheless, most construction equipment manufacturers are supportive of the use of
biodiesel. For example, John Deere has been manufacturing equipment approved for B2 (2% biodiesel
blend) since 2005, and Case has recently announced its acceptance of using B20 in approximately 85% of
its vehicles.44 At the Destiny USA project in Syracuse, NY, biodiesel has been successfully demonstrated
to run all diesel equipment for a large construction project on B100.45
Although many engines are able to run on B100, a petroleum/biodiesel mix such as B20 may provide
better performance. Biodiesel has better lubricity than low-sulfur or regular petroleum diesel, even at 1-
2% blends, which could improve engine performance. However, vehicles running on biodiesel may
experience problems in cold temperatures due to biodiesel's higher cloud and pour points compared to
petroleum diesel.46 An additional issue in using biodiesel is its decreased fuel economy in comparison to
petroleum diesel. While the mechanical efficiency of biodiesel and petroleum diesel is the same, the
energy content of biodiesel is 11% lower than that of petroleum diesel. Thus, EIA calculates that using
B20 may decrease fuel economy by 2.2%.47
Table 5 presents CO2 emissions factors for B100 and B20. Since the carbon from biofuels is assumed to
be emitted from other processes if the feedstock is not used for fuel, biofuels are conventionally assumed
to have zero net CO2 emissions. The emission factor for B100 indicates that 0 Ibs of CO2 are emitted for
every gallon combusted, while 17.8 Ibs of CO2 are emitted for one gallon of B20 because it contains 80%
petroleum diesel. The last two columns in the table present the estimated tons of CO2 emissions that could
February 2009
17
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be reduced in the United States if all construction firms replaced 3% or 10% of their petroleum diesel
with biodiesel. If all U.S. construction firms switched to using B20 for 10% of their fuel purchases, CO2
emissions would be reduced by an estimated 2,970 million Ibs (1.43 million metric tons). This would
represent an approximately 1% reduction in total construction sector emissions. A 10% switch to B100
use sector-wide would reduce total sector emissions by approximately 5%.
Table 5: GHG Emissions Reduction Scenarios from Increased Biodiesel Use
Fuel
B100
B20
Emissions*
(Ibs CO2/gallon)
0 Ibs CO2/gallon
17.8lbsCO2/gallon
Estimate of Sector-Wide Emissions Reductions **
Switching to 3% Biodiesel
4,455 million Ibs CO2
2.02 MMTCO2
891 million Ibs CO2
0.40 MMTCO2
Switching to 10% Biodiesel
14,850 million Ibs CO2
6.73 MMTCO2
2,970 million Ibs CO2
1.43MMTCO2
Notes: MMTCO2 = million metric tons of CO2
* 100% biodiesel is conventionally assumed to have zero net carbon emissions. As B20 is a blend of 20% biodiesel and 80%
petroleum diesel, its emissions factor is calculated as 80% of the emissions of 100% petroleum diesel. Emissions factor for
diesel converted from EPA's 2008 Inventory of Greenhouse Gases 1999-2006, Table A-29.
** Estimate of possible emissions reductions from a 3% or 10% switch from petroleum diesel to biodiesel are based on the
2002 fuel consumption estimates and assumptions used in the EPA report, Quantifying Greenhouse Gas Emissions in Key
Industrial Sectors in the U.S. (May 2008). Numbers presented are for the purpose of illustrating the magnitude of sector-wide
reductions only and should not be interpreted as absolute quantities.
Although the majority of biodiesel retail stations are located near biodiesel refineries in the Midwest,
biodiesel blends are becoming increasingly available across the United States. The National Biodiesel
Board maintains an interactive map to find local sales, and sites such as BioTrucker.com provide
resources to locate truck-accessible locations.48
While biodiesel production is increasing rapidly and biodiesel is becoming more readily available, the
costs of using biodiesel may yet be prohibitive for some construction projects. As of March 2008,
wholesale biodiesel costs were approximately $4.60 per gallon for B 100, whereas petroleum diesel was
available wholesale for $3.30 per gallon. Switching entirely to biodiesel therefore has the potential to
increase diesel fuel costs by 40%. The cost of biodiesel is not expected to decrease significantly in the
near future, as the high cost for soybean feedstock is currently the limiting factor in reducing biodiesel
production costs.49 In addition, as mentioned previously, the reduced fuel economy of biodiesel will
increase overall fuel consumption, which will further increase costs. Therefore, the use of biodiesel may
provide a potential for emissions reductions but is not likely a cost-effective solution for most contractors
at the present time.
A LTER r f/
Diesel generators may consume as much fuel as a piece of construction equipment per hour, and are
generally operated over a longer period of time. For example, a large (500-kilowatt) generator that
consumes 15 gallons of diesel per hour emits about 346 Ibs of CO2 (0.16 metric tons) at an average cost
of $35.30 per hour.50 Switching to dual-fuel generators using a mix of natural gas or propane and diesel
could provide a modest emissions benefit. For example, the same system using 95% natural gas and 5%
diesel would produce only 16.5 Ibs CO2/gallon fuel, emitting less than 250 Ibs of CO2 (0.1 1 metric tons)
per hour.51
February 2009
18
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If grid electricity can be made available early at a construction site, using it may provide emissions
reductions over the use of diesel generators. Diesel generators typically produce 1 .54 Ibs CO2 emissions
per kWh of electricity, which is 15% more than the national average for purchased electricity emissions.52
However, the marginal benefit from using purchased (grid) electricity will vary depending on regional
differences in the fuel used for electricity generation (discussed further in Section 2.2).
Alternative energies, such as solar panels at offices or on-site trailers, may also provide an emissions
reduction solution that could also have long-term cost savings. For example, the SolaRover company
designs 5-, 10-, and 20-kilowatt solar panel trailers that provide electricity at 9 cents per kilowatt-hour
(kWh), displacing the need for diesel-powered generators and producing no direct GHG emissions.53 One
construction company was able to provide power for a team of 15 staff using a stationary solar-wind
generator combination.54
Data sources used to estimate construction industry emissions do not differentiate diesel used for
generators from that used for mobile equipment. Therefore, an illustrative example of sector-wide GHG
emissions reductions from using alternatives to diesel-fired generators could not be developed.
Construction is a labor-intensive industry, with more than 7 million employees in the United States.55
Because of the large number of employees in the construction industry, employee commuting may be a
significant, yet often overlooked, source of GHG emissions in the industry.
Figure 8: Average GHG Emissions for Constructing Structural Assemblies
Construction Material GHG Emissions and Sources for
Structural Assemblies
300
250
C 200
TJ
s>
"° 150
3
.E
w 100 -
50
0
On-site
On-site Equipment Use
Equipment & Materials
Transportation
Worker Transportation
Wood
Steel
Material
Concrete
Notes: Values presented are estimated from the graphical results in the source.
Ibs/hundred ft2= Ibs GHG emissions (in CO2 equivalents) per hundred square feet material
Source: Raymond J. Cole, "Energy and Greenhouse Gas Emissions Associated with the Construction of Alternative Structural
Systems," Building and Environment 34 (1999), pages 335 - 348.
One study, comparing GHG emissions associated with use of wood versus steel versus concrete structural
assemblies at a construction site, found that worker transportation to and from the site usually resulted in
greater GHG emissions than either the on-site equipment used or the transportation of equipment and
February 2009
19
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materials to the site.56 The study concluded that the transportation of construction personnel to and from
the construction site contributed 5% to 85% of the total GHG emissions, depending on the assembly.
Averaged across the different structural assemblies, worker transportation accounted for 50-60% of the
on-site GHG emissions associated with wood or steel assemblies and 30% of the emissions for concrete
assemblies. See Figure 8 for the study's results.
Emissions associated with employee commuting are not currently included in the GHG emissions
estimates for the construction sector presented in Section 1 of this report. GHG emissions associated with
employee commuting will vary by project. No data were found on average distance that employees
traveled to a construction site; therefore, no quantitative estimate of the national GHG impacts from
construction employee commuting could be calculated. Opportunities for reducing emissions associated
with commuting include establishing carpools or shuttle vans.
Estimates presented in Section 1 indicate that approximately one -quarter of the construction sector's
GHG emissions are associated with generating the electricity that the sector purchases. Electricity is used
to power central offices, and on construction sites where grid electricity is available, it is used to power
site lighting, trailers, and tools.
Table 6 illustrates how modest electricity conservation efforts can add up to significant GHG emissions
reductions, if implemented sector-wide. Using a national average CO2 emissions factor of 1.36 Ibs CO2
per kWh of electricity, if all U.S. construction firms reduced their electricity use by 10%, the reduction in
CO2 emissions would be an estimated 6.9 billion Ibs (3.13 million metric tons). This would represent an
almost 2.4% reduction in overall sector emissions.
Table 6: GHG Emissions Reduction Scenarios from Electricity Conservation
Source
Electricity
Electricity
Emissions*
1.36 Ibs CO2/kWh
1.37 Ibs CO2
equivalents/ kWh
Estimate of Sector-Wide Emissions Reductions **
Using 3% less electricity
2.07 billion Ibs CO2
0.93 MMTCO2
2.08 billion Ibs CO2e
0.95MMTCO2e
Using 10% less electricity
6.90 billion Ibs CO2
3.13MMTCO2
6.95 billion Ibs CO2e
3.15MMTCO2e
Notes: MMTCO2 = million metric tons of CO2
MMTCO2e = million metric tons of CO2 equivalents (includes CO2, CH4, and N2O)
'Emissions factor converted from eGRID emissions factor national averages for CO2, CH4, and N2O emitted during electricity
generation as of 2004. Note that other GHG emissions (CH4 and N2O) account for an additional 0.01 million Ibs CO2
equivalents/million kWh in comparison to CO2.
** Estimate of possible emissions reductions from using 3% or 10% less electricity from the grid are based on the 2002
electricity consumption estimates and assumptions used in the EPA report, Quantifying Greenhouse Gas Emissions in Key
Industrial Sectors in the U.S. (May 2008). Numbers presented are for the purpose of illustrating the magnitude of sector-wide
reductions only and should not be interpreted as absolute quantities.
While Table 6 applies a national average CO2 emissions factor for electricity, the emissions factor varies
significantly in different regions based on the fuel mix used to generate electricity. Coal-dominant
production in East-Central states produces more GHG emissions per kWh of delivered electricity than
production using renewable energies such as hydroelectricity in Pacific Northwest states. For example,
2004 CO2 emissions factors for electricity output in Ohio and Pennsylvania are approximately four times
February 2009
20
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greater than those of Oregon and Washington.57 Individual construction firms should consider these
regional differences when evaluating their opportunities for GHG reductions.
Reducing office electricity use offers additional opportunities to reduce GHG emissions for the sector.
EPA estimates that as much as 30% of the energy in a typical office building is wasted. From an analysis
of electricity load scenarios for various reduction policies, EPA suggests that 8% electricity reductions are
possible simply from switching lighting options, such as replacing incandescent light bulbs with compact
fluorescent lights. If operational and maintenance changes are made, such as replacing older heating and
cooling equipment with more-energy-efficient systems or shutting down computers at the end of the day,
EPA suggests that 12% reductions are possible. EPA reports that a combination of approaches may
reduce office electricity consumption by over 30%.58
GHG Emissions Impacts for Buildings: Given a common electricity consumption of 15.5 kWh
per square foot annually, reducing energy use by 30% in atypical office space of 50,000 square
feet would avoid 316,000 Ibs (143 metric tons) of CO2 emissions per year. For a mobile office
trailer of 750 square feet, approximately 4,800 Ibs (2.2 tons) of CO2 emissions would be avoided
(a 30% reduction per year).
Cost Impacts for Buildings: Reducing the amount of electricity purchased will lead to lower
operating costs as well as reductions in GHG emissions. EPA's EnergySTAR program estimates
that reducing energy use by 30% in a 50,000 square foot office space can save $25,000 per year.59
Renewable energy-based electricity purchases may further reduce emissions, although the magnitude of
emissions reductions possible will depend on the percentage of renewable electricity available.
7-3 RED [jcr FJG [ r\/i FA crs o F Co FJSTR rjcno w MATER FA \5
Standard methods for estimating GHG emissions, such as those presented in Section 1, typically include
only traditionally quantified emissions sources, such as fossil fuel combustion and purchased electricity.
Some researchers take a more comprehensive approach by including the full lifecycle emissions
associated with an activity's supply chain and waste management. For the construction sector, a lifecycle
approach could include the GHGs emitted from all construction materials used and disposed as well as the
fuel and electricity used for the materials' production, use, and disposal. Although a comprehensive
construction-related lifecycle emissions inventory has not been conducted, there clearly are opportunities
to reduce emissions by recycling and/or reusing materials, improving shipping methods, and/or selecting
different materials.
Wastes from new construction, renovation, and demolition projects generate about 25% of the total U.S.
solid waste volume.60 Energy is expended and GHGs are released during the manufacturing and
transportation of construction materials. When materials are reused or recycled, the associated emissions
that would have occurred during virgin material manufacturing are avoided. Recycling is the process of
reprocessing or reforming used materials into new products, while reuse is the process of using a
recovered, previously used product instead of a new product. As shown in Table 7, opportunities for
materials recycling or reuse exist across construction supplies. For example, two-thirds of recovered
asphalt is used for new asphalt hot mixes, and one-third is used as sub-base material for paved roads. In
practice, only asphalt, steel, metals, and concrete have been recycled or reused in significant volumes in
the United States, because there are established secondary markets for these used materials.
February 2009 21
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Table 7: Secondary Use Markets for Various Construction and Demolition Materials
Material
CONCRETE
ASPHALT
PAVEMENT
WOOD
GYPSUM
WALLBOARD
ASPHALT
SHINGLES
Generating Activity
Building construction
Building demolition,
Infrastructure demolition
Road, parking lot, and
driveway maintenance and
reconstruction
Building deconstruction
Building construction
Building demolition
Land clearing
Building construction
Building demolition
Building construction
Building demolition
Building renovation
Recycling Markets | Percent
Road base
Aggregate for new asphalt
hot-mixes
General fill
Other
Aggregate for concrete mix
Rip-rap
TOTAL
Aggregate for new asphalt
hotmixes
Sub-base for paved roads
TOTAL
Recovered lumber remilled
into flooring
Mulch and compost
Animal bedding
Feed stock for particle board
Biomass fuel for boilers
Gypsum wallboard
Portland cement
Land application in
agriculture
Asphalt mixes
Road base
Cement kilns
68%
9%
7%
7%
6%
3%
100%
66%
33%
100%
Not
available
Not
available
Not
available
Substitutes for:
Virgin aggregate
Virgin aggregate
Virgin aggregate
Virgin aggregate
Virgin aggregate
Virgin aggregate
Virgin aggregate
Virgin aggregate
Virgin lumber
Scrap wood from
sawmills, logging
debris
Virgin gypsum
Virgin gypsum
Virgin gypsum
Virgin aggregate;
virgin bitumen
Virgin aggregate
Note: With the exception of concrete and asphalt debris, which have well-established recycling markets, data are not well
documented concerning the quantities of wood, wallboard, and asphalt shingles used in various applications.
Source: U.S. EPA, Waste and Materials-Flow Benchmark Sector Report: Beneficial Use of Secondary Materials - Construction &
Demolition Debris, draft in progress.61
EPA's preliminary estimates indicate that 170 million tons of building-related construction and
demolition (C&D) materials were generated in the United States in 2003.62 Of that quantity, as much as
48% was recovered, and the remainder was disposed in a landfill.63 Recovering these materials rather than
disposing of them may prove to be a significant opportunity to reduce GHG emissions, considering that
between 2000 and 2030, an estimated 27% of existing buildings will be replaced and 50% of the total
future building stock has yet to be constructed.64 Considerable uncertainty is associated with EPA's C&D
materials estimates. For instance, the method used to estimate building-related materials relied on data
from a limited number of waste assessments, some of which were outdated. However, as there is no
centralized, national source for information on quantities of C&D materials generated or recycled, the
estimates in these reports are considered to be the best available data.
Table 8 presents the GHG emissions that currently are avoided through recycling various construction
materials. Most of the emissions factors in this table are from EPA's WARM model, which includes
estimates of the emissions avoided during the extracting and processing of raw materials (e.g., the
emissions produced by bauxite mining for aluminum) as well as the emissions from the manufacturing of
the material.65' WARM offers an emissions factor for concrete recycling under the category "aggregates,"
which refers to the replacement of virgin crushed aggregate material with the concrete being recycled.66
February 2009
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In addition, WARM offers the option to calculate emissions related to the transportation of these materials
to waste management facilities.
The recycling estimates in Table 8 are from multiple sources. For some of the materials, national
estimates could not be identified, especially for the less commonly recovered construction materials such
as plastics. For materials where recycling data are available, the CO2e emissions avoided are estimated.
For example, the table shows that for every ton of asphalt recycled from construction, 0.03 tons of CO2e
emissions are avoided. An estimated 139 million tons/year of asphalt are recycled in the United States,
resulting in 4.2 million tons of CO2e emissions avoided.67
Table 8: GHG Emissions Avoided through Recycling or Reuse of Construction and Demolition
Materials
Material
Steel
Carpet
Wood/Lumber
Plastics (mixed)
Aluminum
Asphalt
Concrete
Emissions Factor
for Recycled
Material
(metric ton CO2e/
short ton material)
1.79
7.18
2.46
1.49
13.57
0.03
0.01
Recovery Rate **
97.5% (structural)
65% (reinforcement)
4.6%
*
*
15%
80%
*
Quantity of
Material Recycled
Annually in U.S."
40 million tons
120,000 tons
*
*
*
139 million tons
140 million tons
CO2e Emissions
Avoided
Through
Recycling
(metric tons CC^e)
71,600,000
862,000
*
*
*
4,170,000
1,400,000
Notes:
* Unknown.
** For construction-related quantities of the material, (e.g., 97.5% of structural steel used in construction, or 40 million tons/year, is
recycled).
Sources: Emissions factors for steel, carpet, wood, plastics, concrete (aggregate) and aluminum are from EPA's Waste Reduction
Model — Results. Model estimate methodology from: Solid Waste Management and Greenhouse Gases: A Life-Cycle
Assessment of Emissions and Sinks (EPA530-R-02-006); available at: http://www.epa.gov/mswclimate/greengas.pdf.
Emissions factor for asphalt is from EPA's Waste and Materials-Flow Benchmark Sector Report: Beneficial Use of Secondary
Materials - Construction & Demolition Debris, draft in progress.
Emissions factor for concrete is from Arpad Horvath, "Construction Materials and the Environment," Annual Review of Environment
and Resources, 2004, p. 1 89.
Annual concrete recycled quantity is from CMRA, www.concreterecycling.org.
Steel recycling rates and quantity are from personal communication with Bill Heenan, President of the Steel Recycling Institute, and
"Fact sheet: 2006 rates," http://www.recycle-steel.org/PDFs/2006Graphs.pdf. Of the 40 million tons recycled, approximately 28
tons are structural and 1 2 tons are reinforcement steel.
Carpet recycling rate is from http://www.carpetrecovery.org/pdf/annual_report/06_CARE-annual-rpt.pdf.
Asphalt recycled quantity is provided from personal communication of EPA estimates.
In addition to reducing GHG emissions, recycling may be more cost-effective than disposal. Tipping fees
at recycling centers are typically less than at landfills regardless of waste type; for example, in San Diego,
California, tipping fees for a ton of mixed construction waste could be $65 at a recycling center, but may
February 2009
23
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be $85 to dispose of the same ton at a landfill.68 Even if a contractor must be hired to haul the materials to
recycling centers, recycling can provide enough of an incremental benefit to be economical.69 Costs or
savings associated with recycling C&D materials vary regionally, however. Since C&D materials are
primarily regulated at the state level, national information on the average costs, or even ranges of costs, is
not currently available. Even when recycling of C&D materials is cost-effective, other challenges remain,
including the lack of recycling information and a tendency to continue with familiar disposal practices.70
In recent years, some states have established regulations that limit disposal of certain C&D materials in
landfills.71 For example, Massachusetts requires a solid waste facility management plan that includes
recycling and composting, and limits disposal of asphalt, concrete, corrugated cardboard, brick, wood,
and scrap metal in landfills. In California, specific facilities handle inert C&D materials recycling and
C&D wood materials for chipping. While other factors (e.g., landfill space, fuel costs, green building
efforts) may be influential in determining the overall market for recycled material, markets would be
expected to expand if more states were to encourage recycling by limiting C&D disposal.
[VlATERr/LS SELECTrCIV. FRCaJPEr/iEMTr/MD ^KfFMEWT R/iETKOPS
The selection of materials with lower environmental impact provides a range of opportunities to reduce
GHG emissions, although emissions reductions vary considerably depending on the material.
Increasingly, the use of building materials with recycled content is supported as an acceptable measure for
GHG reductions.72 EPA's ReCon tool, designed to compare the GHG impacts of material purchasing and
manufacturing, offers an option to evaluate the benefits of using common materials with various recycled
contents.73 Although useful for items such as lumber, copper, aluminum, or steel, ReCon does not provide
a listing of all items commonly used in the construction industry, nor does it provide estimates of the
monetary costs associated with using recycled materials. EPA's Waste Reduction Model (WaRM),
designed to calculate emissions related to alternative waste management practices, offers a wide range of
materials and practices, and also estimates emissions related to the waste transportation.74 The BEES tool
is a comparative system designed to balance cost and environmental performance when selecting building
products, which may be useful in the decision-making process as it offers options to enter product-
specific detail or compare generic categories.75 All three above tools attempt to provide full lifecycle
estimates of the material, such as emissions resulting from raw material acquisition, manufacture,
transportation, installation, use, and waste management. This life-cycle approach is not appropriate for
use in inventories because of the diffuse nature of the emissions and emission reductions within a single
emission factor.76
Delivery of materials to a construction site also results in GHG emissions. Reducing delivery-vehicle trips
to the construction site results in lower fuel consumption, which will contribute to reduced GHG
emissions. For large projects or group of projects in close proximity, creating a consolidated location for
materials delivery may reduce transport emissions by allowing contractors to request materials and
quantities closer to the time of use. For example, Transport for London in the UK established the London
Construction Consolidation Centre as a pilot project for centralizing construction deliveries. Construction
sites participating in the pilot project report that use of the Centre reduced road transportation to their sites
by 70%, and reduced waste by damage or other losses by 15%.7? Damage was reduced because materials
did not sit unprotected at the construction site. No similar facilities are known to operate in the United
States.
For shipments over a significant distance, switching transportation methods may also enable emissions
reductions. While originally designed for shipping, trucking, and logistics companies, EPA's Freight
Logistics Environmental and Energy Tracking (FLEET) Performance Model can help quantify the current
February 2009 24
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fuel use and emissions of shipments, as well as help evaluate the costs and effectiveness of future
emission reduction strategies.78
Buying locally produced lumber and other materials can reduce the emissions impacts of transporting
materials. The magnitude of these savings varies widely by the construction site location and the source
of the materials. Reducing transportation distances may also reduce the cost of hauling materials.
February 2009 25
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CO^FAJn^FEQFfC CREEKfKOrjSE
Emissions inventories are an accounting of a company's greenhouse gas emissions and sources. In order
to construct an accurate inventory, a consistent and unambiguous method is essential. An accurate
inventory is a powerful resource for tracking annual emissions, identifying areas to reduce emissions, and
even for comparing emissions across companies. An inventory can provide additional value to a
construction company when used to inform clients about the firm's environmental stewardship efforts.
Construction companies interviewed indicate the motivation for constructing an inventory is threefold: the
possible economic benefits from reduced fuel and electricity purchases, the intrinsic environmental
benefit from reduced emissions, and the marketing and public image benefits of being a proactive and
environmentally responsible community member.79
To ensure that emissions are comparably calculated, various groups have developed spreadsheet or
software tools along with complementary protocols on classifying emissions. Most groups provide
generalized formats so the protocol can apply to the widest range of industries possible. Although
standardized spreadsheet calculators allow for comparisons of emissions across companies, the
generalization of sector-specific activities may result in over- or under-estimating emissions. To account
for this issue, some protocols include additional toolsets and guidance to calculate sector-specific
activities. Two of the best-known GHG inventory methods in the United States are:
Q GHG Protocol Corporate Standard—Currently, the most commonly accepted protocol used to
identify emissions sources is the Corporate Standard guidance developed by the World
Resources Institute (WRI) and the World Business Council for Sustainable Development
(WBCSD).80 This guidance document provides standards by which to measure CO2 and the five
other GHGs included in the Kyoto Protocol.81 The WRI/WBCSD Corporate Standard is
consistent with measures proposed by the Intergovernmental Panel on Climate Change (IPCC),
and now serves as the basis of the international reporting standard, the International Organization
for Standardization (ISO) guidance ISO14064-I*2 These standards are not policy-based, meaning
the methods by which emissions are calculated are not determined or influenced by government
or state environmental policies. In the Corporate Standard, emissions are assigned to one of three
"scopes," where Scope 1 includes emissions that directly result from company operations, such as
emissions from industrial operations. Scope 2 includes emissions resulting from energy
purchases, such as electricity generated off-site. Scope 3 includes all other associated emissions
from company operations, such as employee commuting, business travel, or subcontracted work.
Scope 3 may also include any measures of "upstream" emissions embedded in products
purchased by the firm and/or "downstream" emissions associated with transporting and disposing
of products sold by the firm, such as recycling.83 Companies are encouraged to report on all
possible direct and indirect emissions sources at all levels, although WRI considers only Scope 1
and 2 emissions reporting as a requirement of a corporate inventory.
Q Climate Leaders Inventory Guidance—EPA's Climate Leaders program is an industry-
government partnership that works with companies to develop climate strategies. Partner
February 2009 26
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companies commit to reducing their impact on the global environment by completing a corporate-
wide inventory of their GHG emissions, setting aggressive reduction goals, and annually
reporting their progress to EPA. EPA's Climate Leaders Inventory Guidance is based on the
WRI/WBCSD Corporate Standard, and includes guidelines for setting GHG reduction goals in
addition to measuring current emissions. The Climate Leaders program requires the measurement
of indirect emissions from purchased electricity in addition to the direct emissions from fuel use,
industry processes, or refrigeration and air conditioning equipment.84 Goals are set based on the
companies' Scope 1 and 2 emissions.
The WRI/WBCSD and Climate Leaders guidances are both accompanied by spreadsheet-based tools that
companies can use to create an annual inventory of their GHG emissions. The tools include emissions
factors for fuel combustion and purchased electricity, but neither protocol clearly addresses the challenges
specific to the construction industry. First, while companies in all sectors must consider how to assign
responsibility for emissions, this challenge is magnified in construction, where activities are so heavily
dependent on subcontractors. Using the WRI/WBCSD and Climate Leaders protocols, most emissions
from a general contractor that does not own heavy equipment would be related to the contractor's office
operations. All emissions from subcontractors, and thus possibly all site emissions, would not be included
in the contractor's Scope 1 or 2 emissions. Second, frequent use of heavy non-road equipment may
require modified approaches to emissions calculations, since emissions are affected by both the
equipment's load and horsepower.85 Differences in highway and heavy equipment are not reflected in
standard emissions factors for calculations of CH4 and N2O emissions, which, although a small
component of total emissions, should be included in a complete inventory.86
3rZ CURRENT APPROACHES rw CowsTRfJcrrow [INDUSTRY I
As of October 2008, five companies with operations in the construction industry are members of EPA's
Climate Leaders program. For this report, we asked these companies for their insight on the process and
challenges involved in completing an emissions inventory for construction activities. While the Climate
Leaders program requires a standardized emissions inventory for its application, none of the companies
rely solely on this guidance to inventory their activities. The level of detail in the firms' calculations
varies significantly, although most firms follow or expand upon the WRI/WBCSD protocol. Some
companies attempt to include job-specific emissions, primarily to better inform clients of a project's
likely environmental impact. Examples of construction firms' approaches to calculating their GHG
emissions include:87
Q Turner Construction's inventory closely follows the WRI guidance and toolset, recording
corporate-owned activities such as corporate office emissions, corporate fleet vehicle emissions,
and emissions from any fuel use by corporate-owned equipment.88
Q DPR Construction Inc. uses the WRI guidance as a starting point, and has added construction-
specific activities by developing its own database of activities to account for employee
commuting, corporate fleet vehicle use, and vehicle trips needed for the procurement of materials.
Their calculations factor in job site commuting by accounting for differences in workers' vehicles
and days worked, and record variations in electricity emissions by using regionally specific
emissions factors available in EPA's eGRID.89
February 2009 27
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Q Conestoga Rovers & Associates calculates emissions from purchased electricity for its corporate
offices, but considers emissions from electricity at the job site the client's responsibility.90
Q Aggregate Industries calculates office and job site emissions, but does not include electricity used
at its corporate headquarters.91
While these companies record the types and quantities of waste generated and recycled, none are
currently calculating emissions avoided through materials recycling. The lack of information on
emissions factors for various recycled materials, and the lack of guidance encouraging responsibility for
these emissions, has hindered such calculations.
In summary, even though standardized guidance is available, most companies are still grappling to define
the scope of calculations that best reflects the company's operations. These companies' experiences
emphasize the need for a calculator to document emissions from construction-specific activities, as well
as clearer protocols for defining the boundaries of an emissions inventory (e.g., client versus contractor or
subcontractor responsibilities).
-G FJ5TR f JCT[G N-Z FF.Q RC CA LCf J [_AT[G FJ G G [_
As a complement to this report, EPA's Sector Strategies Division is considering developing an easy-to-
use, spreadsheet-based tool for calculating a GHG emissions inventory, designed for construction
companies. Construction-specific detail is required in order to identify specific areas for emissions
reductions. While this tool has not yet been developed, the intention would be to add construction-related
information to the internationally recognized generic protocols.
February 2009 28
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Greenhouse gas emissions from the construction industry result from a wide range of activities by
hundreds of thousands of companies and sites across the country, producing 6% of all U.S. industrial
GHG emissions in 2002. Although aggregate emissions from this large sector are high, no single
construction site or company is a significant contributor. This document describes opportunities to make
modest company-level reductions, which, if put into practice throughout the industry, could reduce
emissions by millions of tons per year. Table 9 shows the estimated magnitude of reductions that could be
achieved if one combination of reduction scenarios were implemented sector-wide. The 5.5 million metric
ton decrease represents an approximately 4% cut in the sector's emissions from fossil fuel and electricity
use. Further reductions could be achieved by increasing recycling.
Table 9: Scenario of Construction Sector-wide GHG Emissions Reductions
Activity
Reduce Equipment Idling
Improve Maintenance & Driver Training
Increase Fuel Switching to Biodiesel (B20)
Improve Electricity Conservation
Additional lifecycle emissions:
Increase Materials Recycling *
Steel
Asphalt
Concrete
Assumption
10% reduction from all off-road diesel
heavy equipment
Combined practices to increase fuel
economy by 3% for heavy equipment
Replace 10% of diesel use with B20
Combined practices to reduce total
electricity use by 10%
Metric tons CO2e
830,000
130,000
1,400,000
3,100,000
Recycle an additional 3%
Recycle an additional 5%
Recycle an additional 10%
Total Scenario Emissions Reductions with recycling
Total Scenario Emission Reductions without recycling
2,150,000
210,000
140,000
7,960,000
5,460,000
Notes: Source data compiled from various government, academic, and industry documents; see endnotes for further details.92
* For construction-related quantities of the material.
To develop Table 9, many assumptions and estimates had to be made when data were unavailable,
resulting in significant uncertainty. More research and data specific to construction are needed to provide
more-refined estimates of the potential for sector-wide GHG reductions. In particular, data are lacking on
the number of pieces of construction equipment by type, their annual operating hours, their current fuel
efficiency, and their emissions while idling. Data on construction and demolition materials recycling is
not tracked nationally, and extrapolating the data that are available to the national level also results in
uncertainty. As future research fills in the missing pieces of data, the construction sector will be able to
better target emission reduction opportunities and quantify results.
Meanwhile, the construction industry can demonstrate the importance of individual firms' decisions in
affecting GHG emissions. Based on currently available information, it appears construction firms will
need to make changes in multiple areas - fossil fuel consumption, electricity use, and materials recycling
- to realize meaningful sector-wide reductions. With the increased awareness of and demand for green
February 2009
29
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construction in recent years, the construction industry has demonstrated its ability to play a leadership role
in promoting environmental stewardship. In addressing the global environmental challenge of climate
change, many construction firms have already taken the initiative to track and reduce the climate impacts
of their operations. A better understanding of the sources and magnitude of each firm's impacts will
enable many more construction firms to contribute to the climate change solution in the years ahead.
February 2009 30
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rj[?5ECTOR 1MZE AKffj ^GfJFCES OF li
2002
NAICS
NAICS Subsector description
Number of
Establishments
Estimated Subsector Emissions by Source
(MMTC02e)
Total
All Sources
(MMTC02e)
Purchased
electricity
(million metric tons CO2)
Natural
Gas
Vehicle fuel use
on-
highway
off-
highway
subtotal
Absolute values
236
23611
23621
23622
237
23711
23712
23713
23721
23731
23799
238
23811
23812
23813
23814
23815
23816
23817
23819
23821
Construction of Buildings
Residential building construction
Industrial building construction
Commercial and institutional building construction
171,662
2,777
37,208
24.28
1.68
16.21
8.13
0.48
5.99
3.42
0.13
1.55
10.35
0.75
6.79
2.37
0.32
1.87
12.73
1.07
8.67
Heavy & Civil Engineering Construction
Water and sewer line and related structures construction
Oil and gas pipeline and related structures construction
Power & communication line & related structures
Land subdivision
Highway, street, and bridge construction
Other heavy and civil engineering construction
12,357
1,403
6,034
8,403
11,239
10,502
5.98
0.92
3.29
1.61
17.64
4.48
0.07
0.19
0.58
1.16
2.04
0.86
0.24
0.19
1.62
0.29
2.43
0.73
2.40
0.45
5.82
0.17
3.24
0.12
8.16
3.16
5.67
0.73
2.52
0.45
13.98
3.33
Specialty Trade Contractors
Poured concrete foundation and structure contractors
Structural steel, precast concrete erection contractors
Framing contractors: Carpentry
Masonry contractors
Glass and glazing contractors
Roofing contractors
Siding contractors
Other foundation, structure, bldg exterior contractors
Electrical Contractors
27,151
4,321
14,455
25,720
5,294
23,192
6,632
2,786
62,586
4.33
1.41
1.09
2.47
0.62
3.69
0.58
0.43
9.23
0.07
0.31
0.20
0.35
0.02
0.61
0.09
0.10
2.14
0.27
0.17
0.06
0.16
0.07
0.50
0.04
0.03
0.05
3.01
0.66
0.81
1.53
0.46
2.25
0.41
0.25
6.27
0.98
0.27
0.02
0.42
0.06
0.33
0.04
0.05
0.77
3.99
0.93
0.83
1.95
0.52
2.58
0.45
0.30
7.04
February 2009
31
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2002
NAICS
23822
23829
23831
23832
23833
23834
23835
23839
23891
23899
NAICS Subsector description
Plumbing, heating, and air conditioning contractors
Other building equipment contractors
Drywall and insulation contractors
Painting and wall covering contractors
Flooring contractors
Tile and terrazzo contractors
Finish carpentry contractors
Other building finishing contractors
Site preparation contractors
All other specialty trade contractors
Number of
Establishments
87,501
6,087
19,598
38,943
12,865
8,950
35,087
3,729
30,496
33,452
Estimated Subsector Emissions by Source
(MMTCO2e)
Total
All Sources
6.67
1.68
0.57
2.68
1.42
0.71
2.81
0.67
8.21
6.28
(MMTCO2e)
Purchased
electricity
3.57
0.37
0.06
0.57
0.42
0.17
0.68
0.14
0.91
1.21
(million metric tons CO2)
Natural
Gas
1.30
0.01
0.23
0.15
0.14
0.06
0.24
0.07
0.45
0.43
Vehicle fuel use
on-
highway
1.70
1.05
0.24
1.60
0.84
0.43
1.62
0.39
0.44
3.37
off-
highway
0.09
0.25
0.03
0.36
0.03
0.05
0.27
0.07
6.41
1.27
subtotal
1.80
1.30
0.27
1.96
0.86
0.48
1.89
0.46
6.85
4.65
Percent of all construction subsectors
236
23611
23621
23622
237
23711
23712
23713
23721
23731
23799
238
23811
23812
23813
23814
Construction of Buildings
Residential building construction
Industrial building construction
Commercial and institutional building construction
24.16%
0.39%
5.24%
18.43%
1.28%
12.29%
25.82%
1.52%
19.02%
28.79%
1.09%
13.05%
18.09%
1.32%
11.87%
7.66%
1.02%
6.03%
14.42%
1.21%
9.82%
Heavy & Civil Engineering Construction
Water and sewer line and related structures construction
Oil and gas pipeline and related structures construction
Power & communication line & related structures
Land subdivision
Highway, street, and bridge construction
Other heavy and civil engineering construction
1.74%
0.20%
0.85%
1.18%
1.58%
1 .48%
4.53%
0.73%
2.59%
1.20%
13.22%
3.23%
0.21%
0.60%
1.83%
3.68%
6.49%
2.74%
2.02%
1.59%
13.63%
2.43%
4.25%
1 .28%
4.20%
0.79%
10.17%
0.30%
10.46%
0.38%
26.30%
10.19%
6.43%
0.83%
2.86%
0.51%
15.84%
3.78%
Specialty Trade Contractors
Poured concrete foundation and structure contractors
Structural steel, precast concrete erection contractors
Framing contractors: Carpentry
Masonry contractors
3.82%
0.61%
2.03%
3.62%
3.40%
1.08%
0.86%
1.92%
0.21%
1.00%
0.64%
1.13%
2.30%
1 .40%
0.47%
1.38%
5.26%
1.15%
1.41%
2.67%
3.16%
0.89%
0.07%
1.37%
4.52%
1.05%
0.94%
2.21%
February 2009
32
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2002
NAICS
23815
23816
23817
23819
23821
23822
23829
23831
23832
23833
23834
23835
23839
23891
23899
NAICS Subsector description
Glass and glazing contractors
Roofing contractors
Siding contractors
Other foundation, structure, bldg exterior contractors
Electrical contractors
Plumbing, heating, and air conditioning contractors
Other building equipment contractors
Drywall and insulation contractors
Painting and wall covering contractors
Flooring contractors
Tile and terrazzo contractors
Finish carpentry contractors
Other building finishing contractors
Site preparation contractors
All other specialty trade contractors
Number of
Establishments
0.75%
3.26%
0.93%
0.39%
8.81%
12.32%
0.86%
2.76%
5.48%
1.81%
1.26%
4.94%
0.52%
4.29%
4.71%
Estimated Subsector Emissions by Source
(MMTCO2e)
Total
All Sources
0.49%
2.87%
0.45%
0.34%
7.23%
4.95%
1.31%
0.43%
2.08%
1.10%
0.55%
2.17%
0.52%
5.93%
4.83%
(MMTCO2e)
Purchased
electricity
0.08%
1.93%
0.29%
0.32%
6.78%
11.33%
1.17%
0.21%
1.80%
1.32%
0.54%
2.17%
0.45%
2.88%
3.83%
(million metric tons CO2)
Natural
Gas
0.63%
4.25%
0.35%
0.29%
0.44%
10.93%
0.12%
1.96%
1.29%
1.14%
0.50%
2.01%
0.55%
3.81%
3.60%
Vehicle fuel use
on-
highway
0.81%
3.93%
0.71%
0.43%
10.95%
2.98%
1.84%
0.42%
2.79%
1.46%
0.76%
2.82%
0.68%
0.78%
5.89%
off-
highway
0.18%
1.06%
0.13%
0.16%
2.49%
0.30%
0.80%
0.10%
1.17%
0.09%
0.16%
0.87%
0.22%
20.65%
4.11%
subtotal
0.59%
2.92%
0.51%
0.34%
7.98%
2.04%
1.47%
0.31%
2.22%
0.98%
0.55%
2.14%
0.52%
7.76%
5.26%
Source: Number of Establishments, fuel, and electricity purchases collected from 2002 U.S. Economic Census Industry Series reports for Construction (NAICS
23). Fuel and electricity purchases were converted into emissions using the method provided in the EPA Sector Strategies Division report, Quantifying
Greenhouse Gases in Key Industrial Sectors of the U.S., May 2008.
February 2009
33
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APPENDIX B: DETAILS OF 2002 CONSTRUCTION SUBSECTOR EMISSIONS INTENSITY
2002
NAICS
code
236
23611
23621
23622
237
23711
23712
23713
23721
23731
23799
238
23811
23812
23813
23814
23815
23816
23817
23819
23821
23822
23829
23831
23832
23833
23834
23835
NAICS Subsector description
Emissions
(million metric
tons of CO2e)
Value Added
2002
(thousand dollars)
Intensity
(MTCO2e/
2002k$)
Construction of Buildings
Residential building construction
Industrial building construction
Commercial and institutional building construction
24.28
1.68
16.21
93,736,269
6,252,044
71,881,873
0.26
0.27
0.23
Heavy & Civil Engineering Construction
Water and sewer line and related structures construction
Oil and gas pipeline and related structures construction
Power and communication line and related structures construction
Land subdivision
Highway, street, and bridge construction
Other heavy and civil engineering construction
5.98
0.92
3.29
1.61
17.64
4.48
16,021,682
7,662,710
23,045,082
14,374,486
36,210,630
12,042,082
0.37
0.12
0.14
0.11
0.49
0.37
Specialty Trade Contractors
Poured concrete foundation and structure contractors
Structural steel and precast concrete/ Structural steel erection contractors
Framing contractors: Carpentry
Masonry contractors
Glass and glazing contractors
Roofing contractors
Siding contractors
Other foundation, structure, and building exterior contractors
Electrical contractors
Plumbing, heating, and air conditioning contractors
Other building equipment contractors
Drywall and insulation contractors
Painting and wall covering contractors
Flooring contractors
Tile and terrazzo contractors
Finish carpentry contractors
4.33
1.41
1.09
2.47
0.62
3.69
0.58
0.43
9.23
6.67
1.68
0.57
2.68
1.42
0.71
2.81
18,211,099
5,823,411
8,587,264
13,174,159
3,513,111
12,800,818
2,262,269
2,045,722
51,676,783
66,878,082
10,092,652
18,042,291
11,516,137
4,868,960
3,753,983
9,762,425
0.24
0.24
0.13
0.19
0.18
0.29
0.26
0.21
0.18
0.10
0.17
0.03
0.23
0.29
0.19
0.29
February 2009
34
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2002
NAICS
code
23839
23891
23899
NAICS Subsector description
Other building finishing contractors
Site preparation contractors
All other specialty trade contractors
Emissions
(million metric
tons of CO2e)
0.67
8.21
6.28
Value Added
2002
(thousand dollars)
3,403,706
23,114,914
15,339,069
Intensity
(MTCO2e/
2002k$)
0.20
0.36
0.41
Source: Emissions were calculated by subsector for fuel and electricity purchases collected from 2002 U.S. Economic Census Industry Series reports for
Construction (NAICS 23). Fuel and electricity purchases were converted into emissions using the method provided in the EPA Sector Strategies Division report,
Quantifying Greenhouse Gases in Key Industrial Sectors of the U.S., May 2008. Value added collected for each subsector from 2002 U.S. Economic Census
Industry Series reports for Construction (NAICS Sector 23). Selected Statistics for Establishments by Specialization. Released November 21, 2005.
February 2009
35
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C: CGrrsTFrjc~[Oi\r
GF/GG/
Code
Title
Description
23611
Residential building construction
Establishments primarily responsible for the construction or remodeling and renovation of single-family and multifamily
residential buildings. Included in this industry are residential housing general contractors (i.e., new construction,
remodeling or renovating existing residential structures), operative builders and remodelers of residential structures,
residential project construction management firms, and residential design-build firms.
23621
Industrial building construction
Establishments primarily responsible for the construction (including new work, additions, alterations, maintenance, and
repairs) of industrial buildings (except warehouses). The construction of selected additional structures, whose
production processes are similar to those for industrial buildings (e.g., incinerators, cement plants, blast furnaces, and
similar nonbuilding structures), is included in this industry. Included in this industry are industrial building general
contractors, industrial building operative builders, industrial building design-build firms, and industrial building
construction management firms.
23622
Commercial and institutional
building construction
Establishments primarily responsible for the construction (including new work, additions, alterations, maintenance, and
repairs) of commercial and institutional buildings and related structures, such as stadiums, grain elevators, and indoor
swimming pools. This industry includes establishments responsible for the on-site assembly of modular or prefabricated
commercial and institutional buildings. Included in this industry are commercial and institutional building general
contractors, commercial and institutional building operative builders, commercial and institutional building design-build
firms, and commercial and institutional building project construction management firms.
23711
Water and sewer line and related
structures construction
Establishments primarily engaged in the construction of water and sewer lines, mains, pumping stations, treatment
plants and storage tanks. The work performed may include new work, reconstruction, rehabilitation, and repairs.
Specialty trade contractors are included in this group if they are engaged in activities primarily related to water and
sewer line and related structures construction. All structures (including buildings) that are integral parts of water and
sewer networks (e.g., storage tanks, pumping stations, water treatment plants, and sewage treatment plants) are
included in this industry.
23712
Oil and gas pipeline and related
structures construction
Establishments primarily engaged in the construction of oil and gas lines, mains, refineries, and storage tanks. The
work performed may include new work, reconstruction, rehabilitation, and repairs. Specialty trade contractors are
included in this group if they are engaged in activities primarily related to oil and gas pipeline and related structures
construction. All structures (including buildings) that are integral parts of oil and gas networks (e.g., storage tanks,
pumping stations, and refineries) are included in this industry.
23713
Power and communication line
and related structures
construction
Establishments primarily engaged in the construction of power lines and towers, power plants, and radio, television,
and telecommunications transmitting/receiving towers. The work performed may include new work, reconstruction,
rehabilitation, and repairs. Specialty trade contractors are included in this group if they are engaged in activities
primarily related to power and communication line and related structures construction. All structures (including
buildings) that are integral parts of power and communication networks (e.g., transmitting towers, substations, and
power plants) are included.
February 2009
36
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Code
23721
23731
23799
23811
23812
23813
23814
23815
23816
23817
23819
Title
Land subdivision
Highway, street, and bridge
construction
Other heavy and civil engineering
construction
Poured concrete foundation and
structure contractors
Structural steel and precast
concrete/ Structural steel erection
contractors
Framing contractors: Carpentry
Masonry contractors
Glass and glazing contractors
Roofing contractors
Siding contractors
Other foundation, structure, and
building exterior contractors
Description
Establishments primarily engaged in servicing land and subdividing real property into lots, for subsequent sale to
builders. Servicing of land may include excavation work for the installation of roads and utility lines. The extent of work
may vary from project to project. Land subdivision precedes building activity and the subsequent building is often
residential, but may also be commercial tracts and industrial parks. These establishments may do all the work
themselves or subcontract the work to others. Establishments that perform only the legal subdivision of land are not
included in this industry.
Establishments primarily engaged in the construction of highways (including elevated), streets, roads, airport runways,
public sidewalks, or bridges. The work performed may include new work, reconstruction, rehabilitation, and repairs.
Specialty trade contractors are included in this group if they are engaged in activities primarily related to highway,
street, and bridge construction (e.g., installing guardrails on highways).
Establishments primarily engaged in heavy and engineering construction projects (excluding highway, street, bridge,
and distribution line construction). The work performed may include new work, reconstruction, rehabilitation, and
repairs. Specialty trade contractors are included in this group if they are engaged in activities primarily related to
engineering construction projects (excluding highway, street, bridge, distribution line, oil and gas structure, and utilities
building and structure construction). Construction projects involving water resources (e.g., dredging and land drainage),
development of marine facilities, and projects involving open space improvement (e.g., parks and trails) are included in
this industry.
Establishments primarily engaged in pouring and finishing concrete foundations and structural elements. This industry
also includes establishments performing grout and shotcrete work. The work performed may include new work,
additions, alterations, maintenance, and repairs.
Establishments primarily engaged in: (1) erecting and assembling structural parts made from steel or precast concrete
(e.g., steel beams, structural steel components, and similar products of precast concrete); and/or (2) assembling and
installing other steel construction products (e.g., steel rods, bars, rebar, mesh, and cages) to reinforce poured-in-place
concrete. The work performed may include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in structural framing and sheathing using materials other than structural steel or
concrete. The work performed may include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in masonry work, stone setting, bricklaying, and other stone work. The work
performed may include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in installing glass panes in prepared openings (i.e., glazing work) and other glass
work for buildings. The work performed may include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in roofing. This industry also includes establishments treating roofs (i.e., spraying,
painting, or coating) and installing skylights. The work performed may include new work, additions, alterations,
maintenance, and repairs.
Establishments primarily engaged in installing siding of wood, aluminum, vinyl or other exterior finish material (except
brick, stone, stucco, or curtain wall). This industry also includes establishments installing gutters and downspouts. The
work performed may include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in building foundation and structure trades work (except poured concrete, structural
steel, precast concrete, framing, masonry, glass and glazing, roofing, and siding). The work performed may include
new work, additions, alterations, maintenance, and repairs.
February 2009
37
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Code
23821
23822
23829
23831
23832
23833
23834
23835
23839
23891
23899
Title
Electrical contractors
Plumbing, heating, and air
conditioning contractors
Other building equipment
contractors
Drywall and insulation contractors
Painting and wall covering
contractors
Flooring contractors
Tile and terrazzo contractors
Finish carpentry contractors
Other building finishing
contractors
Site preparation contractors
All other specialty trade
contractors
Description
Establishments primarily engaged in installing and servicing electrical wiring and equipment. Electrical contractors
included in this industry may include both the parts and labor when performing work. Electrical contractors may perform
new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in installing and servicing plumbing, heating, and air-conditioning equipment.
Contractors in this industry may provide both parts and labor when performing work. The work performed may include
new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in installing or servicing building equipment (except electrical; plumbing; heating,
cooling, or ventilation equipment). The repair and maintenance of miscellaneous building equipment is included in this
industry. The work performed may include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in drywall, plaster work, and building insulation work. Plaster work includes applying
plain or ornamental plaster, and installation of lath to receive plaster. The work performed may include new work,
additions, alterations, maintenance, and repairs.
Establishments primarily engaged in interior or exterior painting or interior wall covering. The work performed may
include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in the installation of resilient floor tile, carpeting, linoleum, and hard wood flooring.
The work performed may include new work, additions, alterations, maintenance, and repairs.
Establishments primarily engaged in setting and installing ceramic tile, stone (interior only), and mosaic and/or mixing
marble particles and cement to make terrazzo at the job site. The work performed may include new work, additions,
alterations, maintenance, and repairs.
Establishments primarily engaged in finish carpentry work. The work performed may include new work, additions,
alterations, maintenance, and repairs.
Establishments primarily engaged in building finishing trade work (except drywall, plaster and insulation work; painting
and wall covering work; flooring work; tile and terrazzo work; and finish carpentry work). The work performed may
include new work, additions, alterations, or maintenance and repairs.
Establishments primarily engaged in site preparation activities, such as excavating and grading, demolition of buildings
and other structures, septic system installation, and house moving. Earth moving and land clearing for all types of sites
(e.g., building, nonbuilding, mining) is included in this industry. Establishments primarily engaged in construction
equipment rental with operator (except cranes) are also included.
Establishments primarily engaged in specialized trades (except foundation, structure, and building exterior contractors;
building equipment contractors; building finishing contractors; and site preparation contractors). The specialty trade
work performed includes new work, additions, alterations, maintenance, and repairs.
Source: All descriptions reproduced from subsector definitions according to the U.S. Census Bureau for NAICS code 23 (Construction).U.S. Census Bureau, 2002 NAICS
Codes and Titles, Construction, March 23, 2004, http://www.census.gov/epcd/naics02/naicod02.htm, accessed October 6, 2008 Available at:
http://www. census.gov/econ/census02/data/us/USOOO_23.HTM.
February 2009
38
-------
U.S. EPA, "Basic Information," Climate Change. Accessed January 22, 2009.
http://www.epa.gov/climatechange^asicinfo.html
2 Ibid.
3 U.S. Census Bureau,"23 Construction," 2002NAICSDefinitions. May 6, 2003. Available at:
http://www.census.gov/epcd/naics02/def/NDEF23.HTM
BusinessDictionary.com, "construction industry." Definition, 2009 Available at:
http://www.businessdictionary.com/defmition/construction-industry.html
U.S. Census Bureau, County Business Patterns (CBP), 2006, available at:
http://www.census.gov/epcd/cbp/view/cbpview.html.
U.S. Environmental Protection Agency (U.S. EPA), Quantifying Greenhouse Gas Emissions in Key
Industrial Sectors, Sector Strategies Division, May 2008.
Emissions calculated for Sector Strategies, based on the U.S. Department of Energy (DOE) 2002
Manufacturing Energy Consumption Survey and EPA's Inventory of U.S. Greenhouse Gas Emissions and
Sinks: 1990-2006. U.S. Department of Energy, Energy Information Administration (EIA), 2002
Manufacturing Energy Consumption Survey, 2005. U.S. Environmental Protection Agency, Inventory of
U.S. Greenhouse Gas Emissions and Sinks: 1990-2006, 2008.
7 Methane (CH4) emissions from uncontrolled heavy-duty gasoline vehicles are estimated by the U.S. EPA's
NONROAD model to be 20 times the emissions from equipment with low-emissions vehicle technology.
IPCC, 2006 National Guidelines for Greenhouse Gas Inventories, 2006, Table 3.2.3. Available online at:
http://www.ipcc-nggip.iges.or .jp/public/2006gl/pdf/2_Volume2/V2_3_Ch3_Mobile_Combustion.pdf
2004 state electricity emissions factors for C02, CH4, and N20. EPA, eGRID, available at:
http://www.epa.gov/cleanenergy/energy-resources/egrid/index.html.
The AEO 2008 produces estimates as model output of the EIA National Energy Modeling System's
Industrial Sector Demand module, based on the following sources: DOE's 2002 Manufacturing Energy
Consumption Survey; aggregated construction sector data of the U.S. Department of Commerce, Census
Bureau, Economic Census 2002: Construction Industry Series; the EIA's Fuel Oil and Kerosene Sales
2002; and EIA's 2006 release of State Energy Data System 2003. In order to calculate energy
consumption, these estimates delineate fuel usage per value output as Unit Energy Consumption (UEC)
ratios, since the source data relate to total energy consumption and provide no information on the
processes or end-uses. For diesel, gasoline, and purchased electricity, C02 emissions are calculated as the
product of an EIA emissions factor and the modeled energy consumption.
U.S. Census Bureau, 2002 Economic Census: Industry Series Reports, Construction. November 22, 2005.
Available online at: http://www.census.gov/econ/census02/guide/TNDRPT23.HTM.
11 For example, EIA calculates that about 97% (1902.5 MMT C02e) of total fossil fuel combustion from
mobile sources in 2007 is C02; the remaining 3% of emissions are CH4 andN20 (respectively 5.1 and
56.2 MMT C02e). This report does not attempt to correct the fossil fuel consumption estimates of the
source document to account for these additional gases. In order to provide the analyses of total sector and
subsector emissions in this report, C02 and C02e emissions are summed for simplification.
EIA,"Greenhouse Gas Emissions in the U.S. Economy, Emissions of Greenhouse Gases Report. 2008
Available at: http://www.eia.doe.gov/oiaf/1605/ggrpt/index.htmltfeconomy
February 2009 39
-------
20
U.S. Department of Energy, Energy Information Administration (EIA), Annual Energy Outlook 2008, pp.
55 and 63.
13 The six other sectors are those that were included in both the AEO 2008 and the Quantifying Greenhouse
Gas Emissions in Key Industrial Sectors reports. These are: food, paper, chemical (bulk chemical in AEO
and all chemical manufacturing is the EPA report), cement, aluminum, and iron & steel.
Comparable sectors (and average annual emissions rate for 2011-2030) include the food (0.29%/yr), paper
(0.01%/yr), bulk chemical (-1.08%/yr), cement (-0.32%/yr), aluminum (-0.72%/yr), and iron and steel
industries(-0.07%/yr).
Aurora L. Sharrard, H. Scott Matthews, and Michael Roth, "Environmental Implications of Construction
Site Energy Use and Electricity Generation," Journal of Construction Engineering and Management, Vol.
133, No. 11, November 1, 2007.
16 For example, Connecticut limits idling of all motor sources (including off-road engines) to three minutes.
For additional information and regulations of other states, see http://www.epa.gov/otaq/smartway/idle-
state.htm.
17 U.S. EPA, Low Cost Ways to Reduce Air Emissions from Off-Road Diesel Construction Equipment, 2006.
18 Estimates are calculated from an idling study of long-haul trucks, as no construction equipment-specific
studies are available. Lim, Han. Study of Exhaust Emissions from Idling Heavy-Duty Diesel Trucks and
Commercially Available Idle-Reducing Devices, U.S. EPA, October 2002. Table 7.
http://www.epa.gov/oms/smartway/documents/epaidlingtesting.pdf
Huai et al., "Analysis of heavy-duty diesel truck activity and emissions data," Atmospheric Environment
40:2333-2344, 2006.
Analysis by Christopher Steel, Grace Pacific Corporation. E-mail correspondence with Peter Truitt, U.S.
EPA. 1 October 2007.
The 2006 U.S. Census indicates 802,349 total construction establishments. On average, it is assumed each
firm of any size can reduce diesel idling by 10 hours per month, with an average emissions factor of 15 Ibs
C02 per hour from a 2001 model year Class 8 engine. 802,349 firms x 15 Ibs C02/hour x 120 hours/year
= 1.44 billion Ibs C02/year = 0.65 million metric tons C02/year
22 U.S. EPA. "Engine and Vehicle Emissions Reductions," March 2007, available at:
http://es.epa.gov/ncer/rfa/2007/2007_sbir_phasel.html, and Lim, Han. Study of Exhaust Emissions from
Idling Heavy-Duty Diesel Trucks and Commercially Available Idle-Reducing Devices, U.S. EPA, October
2002.
23 Argonne National Laboratory, http://www.transportation.anl.gov/downloads/idling_worksheet.xls.
24 Michigan Occupational Safety and Health Administration, "Carbon Monoxide Hazards from Internal
Combustion Engines: Properly Maintained Forklifts Cost Significantly Less to Operate,"
http://www.michigan.gov/documents/cis_wsh_cet5011_115680_7.doc.
This estimate assumes a typical diesel pickup with an average fuel economy of 15 mpg, traveling 15,000
miles per year, to be applicable for construction company transportation fleets or establishments without
heavy equipment. Assumptions based on review of average vehicle fuel economy data from weblog
responses and EPA fuel economy ratings for used vehicles. U.S. EPA, "Diesel Vehicles," 2008.
https ://www.fueleconomy.gov/feg/diesel. shtml
26 2007 U.S. annual No.2 diesel fuel average cost: EIA, "No. 2 Distillate Prices by Sales Type." Released
September 30, 2008. http://tonto.eia.doe.gov/dnav/pet/pet jri_dist_dcu_nus_a.htm
February 2009 40
-------
27 Giles Lambertson, "Manufacturers Begin to Tout Fuel Efficiency," Construction Equipment Guide.com,
28
30
37
July 16, 2008, http://www.constructionequipmentguide.com/story.asp?story=10902.
2007 U.S. annual No. 2 diesel fuel average cost: EIA, "No. 2 Distillate Prices by Sales Type." Released
September 30, 2008. http://tonto.eia.doe.gov/dnav/pet/pet jri_dist_dcu_nus_a.htm
Giles Lambertson, "Manufacturers Begin to Tout Fuel Efficiency," Construction Equipment Guide.com,
July 16, 2008, http://www.constructionequipmentguide.com/story.asp?story=10902.
Ibid.
31 Articles.DirectoryM.net, "Maximize Fuel Economy: Truck manufacturers offer advice to cut fuel
consumption," July 28, 2008, http://articles.directorym.net/Maximize_Fuel_Economy-a878656.html.
32 Gary Getting, Machine Design, March 6, 2008.
33 Power Source. John Deere. Vol 4, 2005.
34 Duncan, Andy. "Application compensation." July 2008.
http://www.etrucker.com/apps/news/article.asp?id=70341
35 Example based on similar calculation for repowering engines published in the EPA report Cleaner Diesel:
Low-cost Ways to Reduce Emissions from Construction Equipment, March 2007.
36 Ibid.
Some examples of engine costs are provided in the EPA report Cleaner Diesel: Low-cost Ways to Reduce
Emissions from Construction Equipment, March 2007.
38 Calculation from biodiesel refinery feedstock listings of the Center for Agricultural Research and
Development, current as of May 6, 2008. http://www.card.iastate.edu/research/bio/tools/biodiesel.aspx
39 Specification for ASTM D6751 (B(100)). Available at:
http://www.biodiesel.org/pdf_files/fuelfactsheets/BDSpec.pdf.
40 Renewable Fuels Agency, The Gallagher Review of the Indirect Effects ofBiofuels Production, July 2008,
Available at: http://www.dft.gov.uk/rfa/_db/_documents/Report_of_the_Gallagher_review.pdf.
41 E4Tech, Biofuels Review: GHG Savings Calculations, June 2008. Available at:
http://www.dft.gov.uk/rfa/_db/_documents/E4Tech_GHG_saving_calculations.pdf.
42 Renewable Fuels Agency, The Gallagher Review of the Indirect Effects ofBiofuels Production, July 2008,
Available at: http://www.dft.gov.uk/rfa/_db/_documents/Report_of_the_Gallagher_review.pdf.
43 U.S. DOE, Lifetime Cycle Inventory of Biodiesel and Petroleum Diesel for Use on an Urban Transit Bus,
May 1998. Available at: http://www.nrel.gov/docs/legosti/fy98/24089.pdf. Graphic with ethanol
comparison from Kansas Energy Book, 2007. Available at:
http://kec.kansas.gov/chart_book/Chapter5/03_LifeCycleGHGEmissions.pdf.
"Case Approves Use of B20 Biodiesel Blends for Construction Equipment," Reuters, June 17, 2008.
http://www.reuters.com/article/pressRelease/idUS134674+17-Jun-2008+MW20080617.
Mike Stinson and Josh Canner, "Technology, Green Construction at Destiny USA," Associated
Construction Publications, October 6, 2008. http://www.acppubs.com/article/CA6598346.html.
Anthony Radich, Biodiesel Performance, Costs and Use, EIA. Available at:
http://www.eia.doe.gov/oiaf/analysispaper/biodiesel/.
February 2009 41
-------
47 Ibid.
48 National Biodiesel Board, http://www.biodiesel.org/buyingBioDiesel/retailfuelingsites/; BioTrucker.com,
Available at: http://www.biotrucker.com/sites/.
49 Marianne Lavelle, "Going Biodiesel is No Cheap Alternative," U.S. News and World Reports, March 25,
2008.
50 Emissions calculation based on AP-42 emissions standard for diesel stationary combustion sources and
EIA calculation of diesel BTU content, resulting in a factor of 22.88 Ibs C02 emitted per gallon of diesel.
Average diesel cost from EIA prices, http://www.epa.gov/ttn/chief/ap42/ch03/final/c03s04.pdf.
Emissions calculation based on AP-42 emissions standard for duel-fuel stationary combustion sources and
EIA calculation of diesel and natural gas BTU content. Available at:
http://www.epa.gov/ttn/chief/ap42/ch03/final/c03s04.pdf.
Percent comparison of national electricity emissions factor of 1.36 Ibs C02/kWh from EPA's eGRID, as
of 2004, and the EPA emissions factor for uncontrolled diesel stationary combustion. U.S. EPA, AP 42,
Fifth Edition, Volume I, Chapter 3: Stationary Internal Combustion Sources, Table 3.31, Emissions factors
for uncontrolled gasoline and diesel industrial engines, June 2007. Available at:
http://www.epa.gov/ttn/chief/ap42/ch03/final/c03s03.pdf
Emma Ritch, "Sprig Electric Plugs into Mobile? Solar Trailers," San Jose Business Journal, July 4, 2008.
Canadice Construction Company, "Alternative Energy Products,"
http://canadiceconstruction.com/alternativeenergyproducts.nxg.
55 U.S. Census Bureau, County Business Patterns (CBP), 2006. Available at:
http://www.census.gov/epcd/cbp/view/cbpview.html.
56 Raymond J. Cole, "Energy and Greenhouse Gas Emissions Associated with the Construction of
Alternative Structural Systems," Building and Environment 34 (1999), pages 335 - 348.
57 U.S. EPA, Emissions & Generation Resource Integrated Database (eGRID) version 2.1. Available at:
http://www.epa.gov/cleanenergy/energy-resources/egrid/index.html
58 U.S. EPA, "Office Building Energy Use Profile," National Action Plan for Energy Efficiency, Sector
Collaborative on Energy Efficiency, June 2007. Available at: http://www.epa.gov/solar/documents/sector-
meeting/4bi_officebuilding.pdf.
59 U.S. EPA, "Corporate Real Estate Fact Sheet," Energy STAR,
http://www.energystar.gov/ia/business/corp_real_estate/factsheet_0804.pdf.
"C&D Debris State Resources." Construction Industry Compliance Assistance Center.
http://www.cicacenter.org/solidregs.html.
Sources cited in the source document include: Federal Highway Administration, "Transportation
Application of Recycled Concrete Aggregate," 2004; David R. Wilburn and Thomas G. Goonan,
"Aggregates from Natural And Recycled Sources, Economic Assessments for Construction Applications-
A Materials Flow Analysis," U.S. Geological Survey Circular 1176, 1998; Robert H. Falk and G. Bradley
Guy, "Directory of Wood-Framed Building Deconstruction and Reused Building Materials Companies,"
U.S. Forest Service, 2004; and Robert Falk, "Wood-Framed Building Deconstruction, A Source of
Lumber for Construction?" Forest Products Journal, Vol. 52, No. 3, 2002.
U.S. EPA, Characterization of Building-Related Construction and Demolition Debris Materials in the
United States (DRAFT), Municipal and Industrial Solid Waste Division, Office of Solid Waste. Draft in
progress.
February 2009 42
-------
63 The 48% includes managing materials beyond recycling, including reuse and waste-to-energy. Kim
64
65
68
79
Cochran, U.S. EPA Office of Solid Waste, January 12, 2007, personal communication.
Statement within EPA press release: "EPA and Partners Kick Off Green Building Design Challenge;
Contest to reward reuse designs that save resources, costs," May 13, 2008.
U.S. EPA. "Greenhouse Gas Emission Factors (MTC02E per short ton)" Waste Reduction Model. August
2008. Web-based calculator and Excel worksheet available at:
http://www.epa.gov/climatechange/wycd/waste/calculators/WaimJiome.html.
66 Ibid.
Quantity of asphalt from personal communication of EPA estimates.
The City of San Diego, "Potential Benefits of C&D Recycling,"available at:
http://www.sandiego.gov/environmental-services/recycling/cdbenefits.shtml. See also: King County Solid
Waste Division , "Cost-effectiveness of Jobsite Diversion/Recycling.," October 2 2008
.http://www.metrokc.gov/dnrp/swd/greenbuilding/construction-recycling/cost-effectiveness.asp; Recycling
Economics worksheet, available at:
http://www.metrokc.gov/dnrp/swd/greenbuilding/documents/economics_worksheet.xls.
69 Ibid.
70 Arpad Horvath, "Construction Materials and the Environment," Annual Review of Environment and
Resources, 2004, p. 194.
71 New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, Florida, Nebraska, Idaho, and
California.
72 Massachusetts EPA, MEPA Greenhouse Gas Emissions Policy and Protocol,
http://www.mass.gov/envir/mepa/pdffiles/misc/GHG%20Policy%20FrNAL.pdf.
73 EPA's ReCon tool provides basic comparisons of the emissions produced from virgin materials and the
same materials with a selected recycled content. U.S. EPA, "Recycled Content (ReCon)Tool," August 25,
2008. Available at: http://www.epa.gov/climatechange/wycd/waste/calculators/ReCon_home.html.
74 U.S. EPA. "Waste Reduction Model," Climate Change-Waste, September 1, 2008.
http://www.epa.gov/climatechange/wycd/waste/calculators/Warm_home.html
National Institute of Standards and Technology, BEES 4.0. August 20, 2007. Available at:
http://www.bfrl.nist.gov/oae/software/bees/
Comment verbatim from note regarding the WARM and ReCon models. U.S. EPA. "Waste Reduction
Model," Climate Change-Waste, September 1, 2008.
http://www.epa.gov/climatechange/wycd/waste/calculators/Warm_home.html
The pilot consolidation center for construction materials as part of the London Freight Plan purports to
reduce transportation emissions by 75 percent. London Construction Consolidation Centre interim report,
May 2007, http://www.tfl.gov.uk/assets/downloads^sinessandpartners/LCCC-interim -report-may -
07.pdf; News Article, http://www.tfl.gov.uk/corporate/media/newscentre/archive/3525.aspx.
78 U.S. EPA, Shipper/Logistics FLEET Performance Model, 2008,
http://www.epa.gov/smartway/smartway_shippers_software.htm#model.
Summary from interviews with Michael Dean, Turner Construction, Matthew Crandall, DPR
Construction, and Joel Nickel, Aggregate Industries.
February 2009 43
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81
82
80 WRI/WBSCD, "Corporate Standard," The Greenhouse Gas Protocol Initiative,
http://www.ghgprotocol.org/standards/corporate-standard.
The Kyoto Protocol gases are carbon dioxide (C02), methane (CH4); nitrous oxide (N20);
hydrofluorocarbons (HFCs); perfluorocarbons (PFCs); and sulfur hexafluoride (SF6).
WRI/WBSCD, "About the GHG Protocol," The Greenhouse Gas Protocol Initiative,
http://www.ghgprotocol.org/about-ghgp.
WRI/WBSCD, A Corporate Accounting and Reporting Standard, Revised Edition, 2004. Page 25.
Available at: http://www.ghgprotocol.org/files/ghg-protocol-revised.pdf
84 U.S. EPA, "Inventory Guidance," Climate Leaders, August 20, 2008.
http://www.epa.gov/stateply/resources/inventory-guidance.html.
Urbemis, a model developed to calculate emissions from land use, calculates construction equipment-
specific emissions based on the hours operated, average horsepower used, and average load factor during
operation. Rimpo and Associates, Inc., Urbemis 9.2.4, 2008. Available at: http://www.urbemis.com.
According to IPCC emissions factors, CH4 emissions from an uncontrolled gasoline engine are
approximately one-third higher in an uncontrolled gasoline offroad vehicle (33 kg/TJ versus 50 kg/TJ).
2006 IPCC National Guidelines for Greenhouse Gas Inventories, IPCC, 2006. Available at:
http://www.ipcc-nggip.iges.or .jp/public/2006gl/pdf/2_Volume2/V2_3_Ch3_Mobile_Combustion.pdf
87 North Bay Construction, another Climate Leader member, was not available for comment.
88 Michael Dean, Turner Construction, June 18, 2008, personal communication.
89 Mathew Crandall, DPR Construction, August 19, 2008, personal communication.
90
Adam Loney and Greg Carli, Conestoga Rovers and Associates, September 10, 2008, personal
communication.
91 Joel Nickel, Aggregate Industries, October 3, 2008, personal communication.
Idling calculation range from assumptions made in Section 2, reducing 10 hours idling per year for all
construction establishments listed by the U.S. Census Bureau, County Business Patterns (CEP), 2006.
Additional calculation assumes 2 million pieces diesel construction equipment idle 29.4% of 1,500
operational hours per year, of which 10% is reduced per year. See articles: U.S. EPA. "Engine and Vehicle
Emissions Reductions," March 2007, available at: http://es.epa.gov/ncer/rfa/2007/2007_sbir_phasel.html,
and Lim, Han. Study of Exhaust Emissions from Idling Heavy-Duty Diesel Trucks and Commercially
Available Idle-Reducing Devices, U.S. EPA, October 2002.
Maintenance and driver training assumes efficiency improvements in 2 million pieces of diesel off-road
construction equipment, assuming a heavy-heavy duty diesel vehicle with an average 6.6 miles per gallon
operating 1,500 miles per year. See Huai et al., "Analysis of heavy-duty diesel truck activity and emissions
data," Atmospheric Environment 40: 2333-2344, 2006.
Electricity conservation assumes a reduction of 10% from total sector-wide purchased electricity
consumption. See Table 6.
Biodiesel replacement assumes 10% of any diesel fuel consumption (on- or off-highway) is replaced by
B20. See Table 5.
Emissions factor for steel is from EPA's Waste Reduction Model—Results. Model estimate methodology
from: Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks
(EPA530-R-02-006); available at: http://www.epa.gov/mswclimate/greengas.pdf.
February 2009 44
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Emissions factor for asphalt is from EPA's Waste and Materials-Flow Benchmark Sector Report:
Beneficial Use of Secondary Materials - Construction & Demolition Debris, draft in progress.
Emissions factor for concrete is from Arpad Horvath, "Construction Materials and the Environment,"
Annual Review of Environment and Resources, 2004, p. 189.
Annual concrete recycled quantity is from CMRA, www.concreterecycling.org.
Steel recycling rates and quantity are from personal communication with Bill Heenan, President of the
Steel Recycling Institute, and "Fact sheet: 2006 rates," http://www.recycle-
steel.org/PDFs/2006Graphs.pdf. Of the 40 million tons recycled, approximately 28 million tons are
structural and 12 million tons are reinforcement steel.
Asphalt recycled quantity is provided from personal communication of EPA estimates.
February 2009 45
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