Uploaded by Rhona Rose Supeña

CIB DC23134

Development of a Commercial Building Site Selection Framework for
Minimizing Greenhouse Gas Emissions and Energy Consumption
Brent A. Weigel
Ph.D. Candidate
Georgia Institute of
In urbanized areas, building and transportation systems generally comprise the majority of
greenhouse gas (GHG) emissions and energy consumption. The locations of building sites have
significant influence on the built environment’s energy and GHG emissions efficiencies. Thus, the
decision point of site selection and schematic/conceptual design for buildings represents a critical
opportunity for minimizing life cycle GHG emissions and energy consumption. Green building
design and rating frameworks provide some guidance and incentive for the development of more
efficient building and transportation systems. However, current frameworks are based primarily on
prescriptive, component criteria, rather than performance-based, whole-building evaluations. This
paper presents the initial development of a commercial building site selection evaluation framework
for the minimization of GHG emissions and energy consumption of transportation and building
systems. The framework development examines multiple aspects of building site location
efficiencies, including thermal loads on the building envelope, lighting loads, material use/reuse,
and transportation supporting building operation. The expected findings are that whole-building
energy and GHG emissions are sensitive to building site location, and that site-related
transportation is a significant component of performance. The framework and findings will be used
to support the development of quantitative performance evaluations in green building design and
rating systems.
Keywords: site selection, energy efficiency, green building rating systems, sustainable
transportation, location efficiency, building energy use intensity.
1. Introduction
Background and Motivation
Growing international concerns over climate change and sustainable development have
highlighted the need for major reductions in anthropogenic greenhouse gas (GHG) emissions,
particularly in urbanized areas which now contain more than half of the world’s population. In the
U.S., for example, the buildings and transportation sectors account for approximately 38 percent
and 34 percent respectively of direct domestic CO2 emissions [1,2]. Thus, to achieve substantial
reductions in GHG emissions, improved energy efficiencies are needed in urban buildings and
urban transportation systems.
In terms of energy consumption and GHG emissions, the buildings and transportation sectors
share not only similar levels of impact, but also notable efficiency interdependencies. Such
interdependencies are evident in the energy consumption and GHG emission levels of different
types of urban form. Urban form (the spatial arrangement of building types and transportation
networks) influences transportation distances, transportation mode splits, building envelope heat
transfer, and building material use, and each of these factors affect the energy consumption and
GHG emissions of the built environment. It is generally understood among urban planning
researchers and practitioners that on a per capita basis, the efficiency of the built environment
correlates with the development density and land-use mix [3, 4, 5, 6, 7]. Awareness of this
relationship may be helpful in planning new urban development that is more energy efficient;
however, traditional transportation and land-use planning mechanisms (e.g. land-use regulation
and transportation infrastructure programming) are inadequate for capitalizing on improved
efficiency opportunities as they currently (and foreseeably) exist in the built environment. Much of
the built environment (where populations and economic activities are concentrating) is already built,
and much of the new development to come is likely to follow the trend of low-density urban sprawl
– the result of enormous economic and institutional inertia (in the case of the developed world,
notably the U.S.) and aspiration (in the case of the developing world). Thus, efforts to substantially
regulate more compact, mixed-use development or to build large-scale alternative transportation
infrastructures face considerable physical, political, and financial obstacles.
To leverage effectively opportunities for improved efficiencies in the built environment, new
strategies are needed to complement and/or supplant traditional building and transportation
planning strategies. In the U.S., given a large existing building stock where at least half of the
existing buildings will still be standing by mid-century [3], and a largely built-out transportation
system where for the last three decades public spending on transportation operations and
maintenance has exceeded public spending on transportation capital [8], much of the opportunity
for improving the efficiencies of the built environment of today and tomorrow exists in the efficient
utilization of transportation and building infrastructures. Efficient utilization of the built environment
is basically an exercise in matching system users (user needs) to system infrastructure (system
services). In the case of commercial development, the opportunity for matching system users to
system infrastructure occurs at the key decision point of building site selection.
The selection of a building site can influence the potential for energy and GHG emissions efficiency
through site-dependent variables (e.g. transportation distances, transportation mode splits, building
envelope heat transfer, and building material use), and through the increased utilization of the
building stock. A building occupant’s selection of a building site is a decision constrained by
discrete alternatives in the marketplace – the potential for achieving the most efficient utilization of
the built environment is limited by the buildings/locations available at the moment of selection. The
limiting effect of available site alternatives may apply not only to the selection of existing buildings,
but also to the design and construction of new buildings (see section 2.2). To identify building site
locations that maximize the potential for efficiency in the built environment, a performance-based
building site selection evaluation framework is needed.
Sustainable building design and rating systems, such as LEED® (Leadership in Energy and
Environmental Design), offer a reference framework for evaluating and incentivizing greater
efficiency in the built environment. Such rating systems have helped to create a green building
market transformation, thereby increasing the market value of sustainable buildings. Importantly,
sustainable building design and rating systems reward both building-related and transportationrelated energy efficiency measures in green building projects. However, much of the evaluation of
site-dependant energy efficiency measures is prescriptive-based rather than performance-based.
For example, LEED® 2009 for New Construction and Major Renovations encourages urban
density/connectivity and alternative transportation in the building site through the use of
prescriptive criteria, yet the rating system does not include evaluation of transportation energy
savings or GHG emission reduction. Such prescriptive standards may result in site selection
decisions that fail to effectively reduce energy consumption and GHG emissions. Although some
portions of green building rating systems do employ a performance-based approach (e.g. Energy
and Atmosphere Credit 1 of LEED®), these performance-based evaluations do not account for the
relative energy efficiency performance potential of alternative building sites/locations – each project
is evaluated against a site-specific baseline design, after the site has been selected. Considering
the many possible variations in existing conditions and design constraints imposed by different
building sites (existing envelope construction, adjoining conditioned spaces, solar ground reflection
and shading, building footprint limits, available utilities, accommodation of onsite renewable energy
infrastructure etc.), it should be expected that different building sites will achieve different levels of
baseline performance, and that different sites will support different levels of final design
Thus, research is needed to develop a quantitative performance evaluation framework of building
site alternatives – a framework that may be used to evaluate the potential energy consumption and
GHG emissions performance of commercial development.
Research Objective
The objective of the research presented in this paper is to develop a commercial building site
selection evaluation framework that leads to minimization of whole-building energy consumption
and GHG emissions. This research will develop analysis methods for estimating the sitedependent energy consumption and GHG emissions associated with:
1. Architectural energy systems:
a. Heating, ventilating, and air-conditioning
b. Lighting
c. Conveyances
2. Transportation energy systems:
a. Tenant journey-to-work trips
b. Other work-based trips
3. Utility and on-site energy sources
4. Building material use/reuse (future research)
The framework will enable the evaluation of the energy and GHG emissions of architectural and
transportation-related building site aspects, at the key decision point of site selection and
conceptual/schematic design. The framework will eventually be applied to case studies of
commercial office development in the Atlanta, GA metropolitan region. The development and
application of the framework will be limited to the context of commercial office buildings in order to
maintain consistency in the building functions and the site evaluations.
It is anticipated that the results of this research will help develop performance-based standards and
rating systems for sustainable building site selections that enable greater whole-building energy
efficiency and GHG emission reductions. The evaluation framework is intended to help inform
commercial development incentives (green building certifications and/or financial instruments)
aimed at the efficient development and utilization of the built environment.
2. Initial Framework Development
The development of a site selection evaluation framework should be based on the academic
research and professional practices already undertaken to address the energy and GHG
performance of building sites. Currently, no whole-building site selection evaluation framework
exists for quantifying energy consumption and GHG emissions from transportation and building
systems. However, various existing analysis and calculation methods may be adapted and refined
to develop such a framework. Candidate methods may be derived from research and practices in
sustainable building rating systems, building design energy standards, building energy modelling,
traffic impact analyses, travel demand modelling, transportation and land-use interaction research,
and building life cycle analysis studies. Before synthesizing the detailed calculation procedures
needed for the evaluation framework, the relevant aspects of site selection contexts faced by
building occupants need to be understood.
Understanding Site Selection Contexts
Figure 1 outlines the site selection alternatives context from the occupant perspective. The first
question in defining the site selection context is: How does the potential new development relate
spatially to the occupant’s existing development/operations? The answer to this question may have
significant implications for how efficiently the occupant utilizes existing resources (if any). For
example, an owner may have existing property and operations within a given urbanized area, and
is considering expanding the workforce, either by adding an expansion to an existing facility or by
developing another property in the region. If the owner’s planned operations require physical
correspondence between the existing facility and the new expansion, then the role of transportation
energy efficiency is considerably different in this context than if the new facility is completely
independent. Similarly, a facility relocation context can present very unique transportation
efficiency challenges compared to a new location development, since existing facilities attract trips
from an established set of origins (e.g. existing employee commute shed) whereas new locations
do not have an established set of origins.
New Regional
Regional Relocation
Requirements /
Functions /
(floor area)
Fig. 1 Outline of site selection alternatives context (occupant perspective).
The context of site selection is a product of the needs of the occupant, and the availability of site
alternatives in the marketplace. Considering first the needs of the occupant, perhaps the most
important criteria are the amount and type of space required. The amount of required space of
course dictates the scale of the commercial property and supporting infrastructures. Developments
of different scale will potentially have different economies of scale (e.g. different wall to floor area
ratios, centralized vs. de-centralized mechanical systems, etc.). It should be noted that economies
of scale depend upon the normalizing metric of performance (see section 2.4). If the normalizing
metric is building floor area (kWh/SM), then a larger building may be the most efficient choice.
However, if the normalizing metric is building occupancy (kWh/person-hrs), then a smaller building
may be the most efficient choice. The type of space and structure desired or considered (e.g. multitenant high-rise vs. single-tenant low-rise, renovation vs. new construction) affects the potential
variability in energy consumption between potential sites. The needs/requirements must ultimately
be matched to the alternatives available in the marketplace. When considering a renovation, or
simply occupation, of an existing building, clearly the alternatives available in the marketplace will
impact the potential for energy efficiency. In the case of constructing a new building on an
undeveloped site, it may seem as though the potential for energy efficiency is limited only by
available budget, technology, and expertise. However, even an undeveloped site may impose
constraints on the potential energy efficiency of a new building design (e.g. available utility energy,
onsite power generation feasibility, site boundary and topography constraints on building geometry,
zoning laws, transportation mode shares, etc.).
This outline of the site selection alternatives context helps to approach the task of identifying a site
with the greatest energy efficiency potential, but a more detailed framework is needed to begin
calculating energy and GHG emissions performance. The next task in developing the evaluation
framework is to identify the building and transportation variables affected by the development
site/location. Thus, a conceptual framework of the whole-building energy system elements
influenced by site/location is needed.
A Conceptual Framework of Whole-Building Energy System Elements, As They Relate
to a Building Site.
Figure 2 illustrates a conceptual framework of whole-building energy system elements, as they
relate to a building site. In the first three columns of the figure, the energy system elements that
are potentially constrained by the site and potentially variable between different sites are divided
between design, operational, and external (non-design/non-operational) elements. The external
elements include the available utility energy sources that influence fuel-cycle energy efficiency, and
environmental factors that influence loading on the building envelope. The environmental factors
are considered to be beyond the control of the occupant, although some of these elements (e.g.
ground cover and trees) could be within the property boundary and design control of the occupant.
The design elements (2nd column) include aspects of the building architecture and
mechanical/electrical systems that play a role in several building energy systems: space-cooling,
space heating, ventilation, lighting, and materials (embodied energy). The operational elements
(3rd column) include site-dependent aspects of using the building – primarily transportation access
to/from the building. The location of a building within a given transportation network and land-use
context can influence not only trip distances and mode shares for home-based work (HBW), nonhome-based work (NHBW), and non-home-based other (NHBO) trips, but also the rate or number
of trips taken for NHBO trips (e.g. social and dining trips taken during break times). The exterior
lighting schedule has been included in this category since the operation of common area lighting
may not be controlled by the building occupant (e.g. walkway and parking garage lighting for a
multi-tenant building). The conceptual framework accounts for energy system elements that are
generally not dependent on the building site/location (4th column). The element in this category that
has the most extensive impact across whole-building energy systems is the building occupancy.
Building occupancy impacts space-cooling, space-heating, ventilation, lighting, and plug/process
loads, and transportation activity. Furthermore, building occupancy affects the scale of the
development considered in the decision context as well as the per person-hour normalization of
building energy performance. It is assumed here that the estimated occupancy demands of the
tenant are independent of the available site alternatives.
External Elements
Potentially Variable and
Constrained by Site
Design Elements
Potentially Variable and
Constrained by Site
Operational Elements
Potentially Variable and
Constrained by Site
Independent of Site
Utility Fossil
Onsite Alternative
Power Generation
Surface Area to
Volume Ratio
Schedule /
Schedule /
Glazing Area
Misc. Equip. /
Glazing SC/SHGC
Glazing Exterior
Glazing Interior
Plug / Process
Schedule /
Exterior Wall
Exterior Wall
Heat Capacitance
Exterior Wall
Roof Heat
Roof Heat
(Solar Shading)
Ground Cover
(Solar Reflectance)
Cooling System
Type / Efficiency
System Type /
Trip Rates
Trip Distances
Mode Shares
(Solar Shading)
Congestion /
(Actual Fuel
(Trip Rates)
Vehicle Energy
(Base Fuel
System Type /
Interior Lighting
Interior Lighting
Power Density
Exterior Lighting
Interior Lighting
Exterior Lighting
Exterior Lighting
Power Density
Fig. 2 Conceptual framework of whole-building energy system elements, as they relate to a
building site/location.
This conceptual frame provides a point of departure for analyzing and quantifying the relative
performance of building site alternatives. The conceptual framework identifies the energy system
variables that may be affected by the building site, and the framework provides a delineation of
how these variables may be controlled (by design, by operation, or by external factors beyond the
occupant’s control – save by site selection). Different site alternatives considered by an occupant
will likely be constrained in different ways. For example, an office space in a multi-tenant building
may have constrained glazing conductance and shading coefficients (window upgrades are not an
option) whereas purchase of a single-tenant building may have unconstrained glazing properties
(replacement is an option), but potentially no access to natural gas service for heating.
The “design” elements may be controlled either before occupancy (e.g. energy-saving design
features for a new construction building) or post-occupancy (energy-saving retrofits). Similarly, the
operational elements may be controlled before occupancy (e.g. selecting a site with public transit
access) or post-occupancy (teleworking and carpooling programs). The fact that many of the
energy system elements may be controlled or adjusted after occupancy does not necessarily
neutralize the variability existing between sites before occupancy. In other words, post-occupancy
measures for energy efficiency may not be capable of achieving the energy efficiency of an
alternative site. For example, in terms of transportation, if an occupant’s operations will allow only a
maximum of 20% employee teleworking, then an exurban site with 20% employees teleworking
and the remainder (80%) commuting primarily by single occupant vehicles may not achieve the
same transportation energy efficiency as a central business district site with only 50% of
employees commuting by single occupant vehicles and the remainder commuting by public transit,
ridesharing, or non-motorized transportation. The constraints placed on the energy system
elements by the site/location can have a lasting impact on the final-design, post-occupancy,
efficiency potential. The purpose of the evaluation framework under development is to quantify and
compare these impacts of the site alternatives before an alternative is selected.
Accounting for Uncertainty
In a context where the final energy efficiency of a site is affected by post site selection factors, an
evaluation framework’s ability to convey meaningful and representative performance values
requires consideration of performance uncertainty. The motivation for accounting for uncertainty is
derived from an understanding that the uncertainty in the whole-building energy performance of a
given site alternative may exceed the variation in estimated mean performance between site
alternatives. In simple terms, the precision of the performance estimates may, in some cases, be
too wide to determine the relative performance between a pair of potential sites. Whether or not
the precision of the estimates are too wide, some capability for visualizing the range or distribution
of estimated mean differences in energy consumption between pairs of sites could help the
decision maker determine if the degree of uncertainty is acceptable for making a determination of
the most energy efficient site. The uncertainty of the estimated whole-building energy performance
(or mean difference in energy performance between sites) is a result of the propagation of
uncertainty of the calculation inputs. The impact of uncertainty on results calculated in the
evaluation framework will be quantified through sensitivity analysis of the propagation of
Energy Use Intensity (EUI) and GHG Intensity (GHGI)
Effective evaluation and comparison of building energy performance between sites/buildings of
unequal size requires normalized performance metrics or functional units. Normalized building
energy use is typically expressed in terms of the amount of annual energy consumed per unit of
floor area, and is referred to as the energy use intensity (EUI) [9]. Several building design and
operation energy standards and programs utilize EUIs [10, 11, 12, 13], but the measurement
methods vary: different types of energy use are included or omitted (such as plug loads), some
standards measure end use energy while others measure primary energy, and some standards
vary with respect to the building floor area included (e.g. gross area vs. conditioned floor area).
The U.S. Department of Energy (DOE) is working to standardize the measurement of building
energy performance [14]. Since no standard set of performance metrics are yet defined in the
architecture/engineering/construction industries, multiple performance metrics will be utilized in the
framework to analyze how different normalizing units influence performance evaluation.
The Role of Transportation Access in Whole-Building Energy Consumption
The inclusion of transportation energy and GHGs in this framework development is inspired in part
by literature exploring the magnitude of transportation energy with respect to whole building energy
consumption. Currently, the literature offers some evidence of the proportion of whole building
energy consumption related to transportation activity to/from a building site, and the importance of
building location and mode choice on reducing transportation energy. Wilson conducted a study of
the transportation energy intensity of buildings by comparing “driving energy” to “site energy” [15].
Based on national data from the U.S DOE and the U.S. Environmental Protection Agency (EPA) on
driver commute distance and vehicle efficiency, and building energy consumption data from the
U.S. DOE, the study found that for an average office building transportation energy use exceeds
building operation energy use by around 30%. For buildings built to meet applicable energy codes,
transportation energy use is estimated to exceed building operation energy use by 137%. Wilson
advocates the use of transportation energy intensity metrics and the development of benchmarks
for performance. Researchers at the University of Toronto found that for low density residential
developments, transportation accounted for 61% and 31% of GHG emissions and energy use,
respectively; whereas for high density development, transportation accounted for 43% and 18% of
GHG emissions and energy use, respectively [7]. Furthermore, the researchers found that
“Transportation requirements for low density suburban development are nearly 4x as energy and
GHG emissions intensive as high-density urban core development per capita” and “Transportation
requirements for low density suburban development are 2x as energy and GHG emissionsintensive as high-density city core development per unit of living space” [7]. The framework under
development will first examine the energy and GHGs associated with commuter access to the
building site (home-based work trips), since this is generally the largest single transportation
activity for the applied context of commercial office buildings.
3. Discussion of Framework Application
The site selection evaluation framework will be applied to case studies of commercial office sites in
the Atlanta, GA metropolitan area. The case studies to be included will explore the variation in
estimated whole-building energy performance between different types of sites: suburban vs.
downtown, multi-tenant vs. single tenant, new construction vs. existing fit-out.
In the process of exploring the variations in energy and GHG emissions performance between
different types of commercial office sites, the evaluations may be conducted within three distinct
frames of reference:
1. Comparison of schematic designs;
2. Comparison of baselines; or
3. Comparison of baseline to schematic designs (energy reductions).
Comparison of schematic design performance (reference frame #1) is focused on evaluation of site
alternatives in terms of total end-use energy consumption. This comparison accommodates the
most explicit evaluation of total energy consumption, but it is highly sensitive to the uncertainty of
final building design. Thus, a comparison of schematic design performance between site
alternatives may not clearly indicate, under uncertainty, which potential site best supports the best
energy performance (at least not during the early conceptual or schematic design phases).
Alternatively, a comparison of baseline performance between sites (reference frame #2) avoids the
uncertainty of design evolution and final design, and may provide a clearer distinction in the
relative performance of sites. The second reference frame (comparison of baseline performance)
could provide the most targeted identification of the best performing site when utilized in
conjunction with the LEED® energy performance rating system. Currently, the LEED® energy
performance rating system (EA Credit 1) measures building energy performance it terms of percent
reduction (of cost) against a baseline design for the given site. Although the LEED® rating system
rewards improvements made in the energy efficiency of the building stock, the rating system does
not necessarily reward development or occupancy of the most energy efficient building/site that
meets the occupant’s needs. For example, an occupant may select an existing commercial building
with an EUI that far exceeds the national average for the building classification. Proposed
schematic designs for renovating the building may be estimated to achieve 30 – 40 percent energy
reductions against the existing building baseline. Energy reductions of 30 – 40 percent would of
course result in lower levels of final design energy consumption if the baseline design energy
consumption were lower. This fact invites consideration of which site alternative provides the
lowest baseline performance. If the energy reduction percentage intended by the building owner
and designers is independent of the given baseline (percent reduction predetermined to meet
points goal), then selection of the existing building with the lowest baseline energy consumption
will result in development of a building with the lowest final design energy consumption.
Furthermore, selection of the site with the lowest baseline energy consumption may help to reduce
the uncertainty of achieving the best possible energy performance in the final design. If a proposed
energy reduction of 40 percent is eventually changed (due to unforeseen cost or technical barriers)
to a more modest 25 percent, then selection of the site with the lowest baseline energy
consumption would help to preserve or “lock-in” a lower level of final design energy consumption
throughout the evolution of the building design/renovation.
The third reference frame (comparison of energy reductions), essentially follows the current
paradigm of the LEED® rating system, in which more points are awarded for proposed buildings
that reduce a higher percentage of energy relative to their own baselines (albeit in terms of energy
cost rather than units of energy). Evaluation of the percentage energy reduction against a single
site-specific baseline does not properly account for the opportunity to select the most efficient site
available. Evaluation of the most efficient site available requires either establishing a baseline from
among available site alternatives or deriving one (an average or median performance) from the
existing building stock.
4. Conclusion
Realization of a more sustainable built environment that meets the challenges of climate change
mitigation and energy conservation will require greater efficiencies in transportation and building
systems. While the deployment of new technologies will hopefully provide much of the efficiency
gains needed, significant gains in efficiency must still be leveraged from the efficient utilization of
new and existing transportation and building systems. The site selection evaluation framework
under development can help to improve the efficient utilization of transportation and building
systems by helping commercial building occupants satisfy their space and mobility needs with the
most efficient transportation and building infrastructure available in the marketplace. Application of
the site selection evaluation framework to case studies of commercial office development will
provide insight into the opportunities for more efficiently utilizing transportation and building
systems in the built environment. The expected findings are that whole-building energy
consumption and GHG emissions are sensitive to building site location, and that site-related
transportation is a significant component of overall performance.
5. Acknowledgements
This research is supported through a National Science Foundation (NSF) Graduate Research
6. References
U.S. ENERGY INFORMATION ADMINISTRATION, Emissions of Greenhouse Gases in the
United States 2007. DOE/EIA-0573(2007), Department of Energy, Washington, D.C., 2007.
Department of Energy, Washington, D.C., 2009.
BROWN, M., F. SOUTHWORTH, AND T. STOVALL. Towards a Climate-Friendly Built
Environment. Pew Center on Global Climate Change, Washington, D.C., 2005.
CAMBRIDGE SYSTEMATICS, INC., Moving Cooler: An Analysis of Transportation Strategies
for Reducing Greenhouse Gas Emissions. Urban Land Institute, Washington, D.C., 2009.
EWING, R., et al. Growing Cooler: Evidence on Urban Development and Climate Change.
Urban Land Institute, Washington, D.C., 2007.
TRANSPORTATION RESEARCH BOARD, Driving and the Built Environment: The Effects of
Compact Development on Motorized Travel, Energy Use, and CO2 Emissions. Special
Report 298, The National Research Council of the National Academies, Washington, D.C.,
NORMAN, J., H. MACLEAN, AND C. KENNEDY. Comparing High and Low Residential
Density: Life-Cycle Analysis of Energy Use and Greenhouse Gas Emissions. In Journal of
Urban Planning and Development, Vol. 132, No. 1, 2006, pp. 10-21.
CONGRESSIONAL BUDGET OFFICE, Public Spending on Transportation and Water
Infrastructure. Congress of the United States, Washington, D.C., 2010.
PETERSON, K. AND H. CROWTHER. Building EUIs. In High Performing Buildings: A
magazine of the American Society of Heating, Refrigerating and Air-Conditioning Engineers,
Inc., No. Summer, 2010, pp. 40-50.
ASHRAE, Energy Standard for Buildings Except Low-Rise Residential Buildings.
ANSI/ASHRAE/IESNA Standard 90.1-2004, American Society of Heating Refrigerating and
Air-Conditioning Engineers, Inc., Atlanta, GA, 2004.
ASHRAE, Standard Methods of Measuring, Expressing and Comparing Building Energy
Performance. ANSI/ASHRAE Standard 105-2007, American Society of Heating Refrigerating
and Air-Conditioning Engineers, Inc., Atlanta, GA, 2007.
http://www.icleiusa.org/programs/climate/ghg-protocol. Accessed July 7, 2009.
EcoCalculator. Athena Institute. http://www.athenasmi.org/tools/ecoCalculator/. Accessed
August 1, 2010.
BARLEY, D., et al. National Renewable Energy Laboratory, Procedure for Measuring and
Reporting Commercial Building Energy Performance. NREL/TP-550-38601, U.S. Department
of Energy, Washington, D.C., 2005.
WILSON, A. AND R. NAVARO. Driving to Green Buildings: The Transportation Energy
Intensity of Buildings. In Environmental Building News, No. September, 2007, 2007.