Eco-Conscious Architecture Through Life Cycle Assessment for Buildings

Home , Design life

Elena Rivera

Editor Werner Lang Aurora McClain

csd Center for Sustainable Development II-Strategies Analysis

2 2.15 Life Cycle Assessment for Buildings

Eco-Conscious Architecture Through Life Cycle Assess- ment for Buildings

Elena Rivera

Based on a presentation by Dr. David T. Allen

Figure 1: Buildings such as these all have life cycles that encompass construction, operation, and demolition

Introduction environmental impacts of the building over its useful lifetime. “Few problems are less recognized, but more The Office of Energy Efficiency & Renewable important than, the accelerating disappearance Energy, at the U.S. Department of Energy, 4 of the earth’s biological resources. In pushing reports that in the U.S.: other species to extinction, humanity is busy sawing off the limb on which it is perched.” • Two to seven tons of waste (about 4 Prof. Paul Ehrlich, Stanford University1 pounds per square foot) are generated during the construction of a new single- The U.S. Green Building Council reports that family detached house. in the United States buildings alone account • 30 to 35 million tons of construction, reno- for:2 vation, and demolition (C&D) waste are produced by U.S. builders each year. • 72% of electricity consumption, • Roughly 24% of the annual municipal solid • 39% of energy use waste stream is comprised of C&D debris. • As much as 95% of building related • 38% of all carbon dioxide (CO2) emissions • 40% of raw material use, construction waste is recyclable, and most • 30% of waste (136 million tons annually) materials are clean and unmixed. (Fig. 3) • 14% of potable water consumption • Construction waste is about 27% wood. The remaining 73% includes cardboard, Furthermore, in 1990 and 2005 the U.S. paper, drywall/plaster, insulation, siding, ranked highest in the world in energy con- roofing, metal, concrete, asphalt, masonry, sumption and carbon dioxide emissions, even bricks, dirt rubble, waterproofing materials, though it ranked seventh in population.3 and landscaping material. • 15 to 70 pounds of hazardous waste are This data clearly indicates that the built generated during the construction of a environment has the potential to notably detached, single-family house. Hazardous impact our environment and health. In spite wastes include paint, caulk, roofing ce- of the knowledge that buildings contribute ment, aerosols, solvents, adhesives, oils, significantly to greenhouse gas emissions and greases. and consumer large amounts of energy and natural resources, the majority of buildings are These statistics suggest that the process of still designed and built without considering the designing, building, and operating buildings

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offers significant opportunities to reduce the the European Committee for Standardization In spite of these concerns and challenges, burden on the environment. Those involved (CEN), the ATHENA Sustainable Material Insti- LCA continues to be used and is considered in the building sector - architects, designers, tute in Canada, the Danish Building Research particularly useful during the design phase, builders, developers, and planners - have an Institute (SBI) in Denmark, the U.S. National since it offers the opportunity to identify po- opportunity to make decisions that can have Institute of Standards and Technology (NIST), tential environmental issues early on so that a dramatic influence on reducing the envi- the Building Research Establishment (BRE) in they can be addressed in the design phase.8 ronmental impacts of the built environment. the UK, the U.S. Green Building Council, the As LCA methodologies, tools, and applica- The collection and analysis of general data Royal Institute of Technology in Sweden, the tions continue to be studied and refined, LCA on the byproducts of the construction process University of Karlsruhe in Germany, and others practitioners and users should gain greater as well as the availability of extensive data have been, or are currently, involved in devel- expertise in combining LCA with other assess- on specific products has led to the creation of oping LCA standards, tools and/or guidance. ment tools and using the results to support tools that can assist in assessing the impacts decisions aimed at lowering environmental of buildings over their lifetime. These tools are The tools have been developed over the last impacts or improving upon current conditions generally referred to as life cycle assessment 20 years for different purposes by various through regenerative or restorative design. or life cycle analysis (LCA) tools. organizations in multiple countries. As a result the tools vary greatly.4 Some tools are ap- This paper will provide an overview of the LCA Life cycle analysis tools plicable to a range of buildings, while others methodology, including the basic steps for are specific to certain types (e.g., commercial conducting a LCA, how it is being applied to Architects, designers, builders, building vs. residential). Even tools that cover the buildings and the built environment, and will product manufacturers, and others in the same life cycle stages cover them differently provide a listing, comparison and classifica- building design and construction profession, and rely on different databases or guidelines, tion of several of the many LCA tools currently are being encouraged or even required to take therefore they yield different results that can- available, based on a literature review by performance-based and prescriptive actions not be compared. Regional regulations and other authors, to serve as general guidance in toward reducing environmental impacts related cultural factors also have an impact on the navigating the LCA tools. to their practices in, or related to, the built development of LCA tools, thus accounting for environment. Increasingly this is being accom- other differences among the tools. This makes Overview of the LCA process plished, or at least attempted, by using one or comparing the tools difficult and determinin- more LCA tools, e.g., LCA software programs, ing which tool is suitable for a particular user “In principle, all decisions that affect or are standards and guidance documents. While or a specific project is challenging, which may meant to improve the environmental perfor- 4 multiple LCA tools exist, along with a wealth of discourage their use and application. mance of a product/service should be scruti- information, guidance, and standards on as- nized in terms of their life cycle implications. sessing the environmental impacts of buildings The development of standardized LCA tools For the environmental perspective, a product’s and suggestions for reducing those impacts, for buildings or the integration of LCA into the life cycle can be represented as a circular there is no definitive tool or path to follow when design and policymaking process is made movement that ties together resource extrac- it comes to LCAs. more difficult by the complexity of build- tion, production, distribution, consumption ings. For example, a single building can be and disposal. In other words, all the phases of Most of the currently available LCA informa- composed of over 60 basic materials and organized matter and energy that are in some tion, databases, and tools have come about as over 2,000 separate products. Furthermore, way related to the making and use of a product a result of several, sometimes simultaneous according to the International Energy Agency can also be linked to an impact on the environ- 5 9 or partially overlapping, efforts by research (IEA) Annex 31 report, typically a wide variety ment.” Organization for Economic Co-opera- institutions and/or academic groups working of LCA tools are needed, as opposed to just tion and Development, Paris, France, 1995 as partners across the world. Organizations one, since effective LCA tools need to be such as the International Organization for tailored to the specific planning phase and the Life cycle assessment (LCA), also known as Standardization (ISO), the Society of Envi- user’s knowledge base. life cycle analysis (Fig. 3), is a technique that ronmental Toxicity and Chemistry (SETAC), is used to assess the environmental impacts There are some concerns that not all LCA associated with a product, process, or system, results are useful for comparing products, from cradle-to-gate, cradle-to-grave or, if it can buildings or systems since some factors either be recycled, cradle-to-cradle. The concept of get diluted or misrepresented during the life creating cradle-to-cradle materials - closing cycle inventory step or by inconsistent system the loop by not generating any waste - has boundaries, rendering the final results poor recently been championed by William Mc- indicators on which to base decisions. Also, Donough and Michael Braungart as a systems the inability to account for site or location spe- that imitates “nature’s effective cradle-to-cradle cific characteristics can impact the results of a system of nutrient flow and metabolism, in LCA ,since factors such as microclimate, the which the very concept of waste does not impact of one building on an adjacent building, exist”.10 and infrastructure loading in urban areas may not be represented in LCAs.6 However, in spite Figure 4 provides a simplified diagram of the of these limitations, LCAs have demonstrated stages of a life cycle for a product. A cradle- benefits for evaluating overall material and to-grave LCA for a product might assess the energy efficiency, identifying trade-offs in pollu- impacts from the following stages: raw material tion, materials, energy, and operations, as well harvesting, extraction or acquisition; manufac- as for benchmarking efficiency improvements turing or refining; packaging and distribution/ Figure 2: U.S. Carbon Dioxide (CO ) Emissions by Sector 2 and emission reductions.7 transportation; use; and disposal, recycling

4 2.15 Life Cycle Assessment for Buildings

or reuse. Embedded in this analysis is the energy and natural resource consumption for all stages, as well as waste generation and emissions to air, water and soil. Some LCA methodologies also include an assessment of social, cultural, community and/or economic impacts. Therefore, a LCA is said to be holistic because it is designed to cover essentially all phases of a product’s life cycle and all significant impacts, both direct and indirect, that the product has on the environment.11

As a methodology, LCA involves “compiling an inventory of relevant inputs and outputs for a clearly defined system, and then evaluating the potential environmental impacts associated with those inputs and outputs. Results are [then] interpreted in relation to objectives established at the outset.”12 LCA is sometimes confused with the life-cycle costing (LCC) methodology, which differs in that LCC is used to calculate the total cost of ownership over the useful life of the product, whereas LCA involves a qualitative and/or quantitative analysis of environmental impacts over the life of the product. “The two tools are related in that they both take into account how long a particular item will serve its intended purpose and what maintenance it will need during that time. As a result, both tools give credit to items that are long-lived and durable, but LCA involves environmental accounting, while LCC only considers economic value.”13 Figure 3: Life Cycle Analysis of a Building

Often, LCAs are applied to products on a cradle-to-gate, rather than cradle-to-grave basis. This means that the life cycle assessment includes the process of extracting or harvesting the raw materials (the cradle); the intermediate processing, refinement, and fabrication processes; and the manufacture of the final product ready for sale (the factory gate). Since a building or built environment is intended for a use, or life, beyond the factory gate, LCAs for buildings are conducted on a cradle-to-grave, or even cradle-to-cradle, basis. Therefore, data from product LCAs are incorporated into the LCAs for built systems.

When LCA is applied to a building instead of a product, the life cycle stages can be differentiated as: raw material extraction/acquisition (Fig. 5), building material manufacturing (Fig. 6), site preparation and onsite construction (Fig. 7), building use, operation and maintenance (Figs. 8 & 9), and demolition, recycling/ reuse and/or disposal (Fig. 10). Since different LCA tools have different applications or are intended for different users, using a combination of tools is most beneficial. In this approach, a different LCA tool might be selected for each phase, depending upon the objectives of each. Therefore, rather than using a single LCA, a building and its components would undergo Figure 4: Product life cycle

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several LCAs, the results of which can be used at the appropriate stage and/or are integrated to support decision making from the design phase on through the entire life cycle of the building. Specific LCA tools are addressed in a later section in this paper.

LCA phases

The LCA process is carried out in a system- atic, phased approach and is comprised of the following four steps:14 goal definition and Figure 6: Building materials scope, inventory analysis, impact assessment, and interpretation. These four steps or phases are described below and partially illustrated using information from a case study on a residential home in Ann Arbor, Michigan that was analyzed using LCA methodology in order to design a more energy efficient home. A LCA was conducted on a 2,450 square foot residential home built in Ann Arbor, Michigan to determine total energy consumption of building material manufacturing and of construction, use and demolition over a 50-year period, and to determine the global warming potential (GWP) and life cycle cost. The LCA consisted Figure 5: Cement plant Figure 7: Under construction of an assessment of an existing standard home in comparison to a new energy efficient home.

Step 1: Goal definition and scope

The first step in a LCA is to define the goal and scope of the assessment in order to determine the time and resources required. Therefore, this first step includes deciding and determining:

• Why the LCA is being conducted. • What product, process or system will be studied. • What the functional unit(s) will be for the product, process or system. • What the boundaries or limits of the as- Figure 8: Coal mining for electricity generation Figure 9: Power lines transmitting electricity sessment will be, including spatial and temporal boundaries (e.g., what will be included and what will be excluded). • Which environmental concerns will be included (impact categories). • What will be the strategy for data collection • Who will be the audience of the LCA - whether it will be a public and peer reviewed document.15

For the Michigan home case study, the LCA was conducted to help determine how to design an energy efficient home using an existing home for comparison.16 As stated above, the LCA covered energy consumption, GWP, and cost over the life cycle of the home, which was taken to be 50 years.

Defining the system boundaries sets the limits for data collection for the study and can have Figure 10: Demolition

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a significant impact on the outcome of the tion. • Behavioral preferences of inhabitants, LCA. As an example, if you were conducting • Energy (e.g., from utilities) consumed dur- such as food, clothing, furniture, and enter- a LCA that compared incandescent light bulbs ing the occupancy and use phase. tainment equipment. to fluorescent lamps to determine which one • Demolition of the home at the end of its • Indoor air quality issues. had the least impact on the environment, you useful life. • Energy consumption related to treating/ could choose the system boundary to include • Transportation of demolished materials to supplying water and waste treatment, and only the disposal of the bulbs, or you could recycling centers or landfills, excluding the trash pick-up and disposal. set the boundary to encompass the entire concrete foundation and basement floor, • Construction and demolition equipment. life cycle of the bulbs (see Figure 11). If you which it was assumed would remain in • The embodied energy of the industrial chose to examine only disposal of the bulbs, place. facilities that produced raw materials and the fluorescent lamps would appear to be a fabricated products. much worse choice than the incandescent In order to highlight those systems in the built • Environmental issues (e.g., resource use) bulbs, since they contain mercury, a hazardous environment that directly influence the energy and social issues (e.g., effects on local material that would be released upon disposal. use and GWP of a residential home, pro- economy) related to the origin of the con- However, if the entire life cycle of the lamps cesses and factors such as, but not limited to, struction materials. is considered, the incandescent bulb would the following were excluded from the boundary have the higher mercury releases, since more system for the Michigan home: When conducting a LCA, the choice of func- mercury is released by burning coal to provide tional unit is important because it provides the energy for the less efficient incandescent bulb • Site location as it pertains to impacts on means for comparing products and the basis than is released by using and disposing of the local ecosystems, personal transportation for calculating the inputs and outputs in the fluorescent bulb. This example illustrates how issues, and urban planning issues. inventory step. The ISO standards note that the choice of system boundary impacts the • Energy and material issues related to the the functional unit must be clearly defined and outcome of the LCA.17 surroundings, such as landscaping and the measurable. When comparing the impacts of concrete in the driveway. two different paints, the function of the paints Setting boundaries that are too narrow can • Non-appliance furniture. is to cover or coat a surface, so the func- lead to decisions that are not grounded in criti- • Utility and TV/phone/data connections and tional unit could be one square foot of painted cal data, and trying to include every aspect of hook-ups. surface. In this case the resource and energy the life cycle would be too time and resource intensive, if not impossible. Selecting the system boundary should be based on best practices and good engineering judgment, e.g. on the components that account for 1% or more of the raw material use, energy use, and wastes or other emissions.18 Selection of the system boundary should also consider the ob- jective of the LCA as well as elements or steps that could provide critical data. For example, life-cycle elements such as raw materials extraction or acquisition and waste generation can rarely be excluded. If the LCA is being conducted to compare two products and an element is identical for both, then perhaps it can be excluded if the only goal of the analysis is the comparison of the two products. For example, if the LCA involved two products which generate identical solid waste streams, but different air emissions streams, then perhaps the solid waste element could be excluded.

The system boundaries for the Michigan home included energy consumption and GWP gas emissions for processes such as, but not limited to, the following:

• Embodied energy from the following processes: raw material extraction, production of engineered materials like steel plates and wood studs, manufacturing of building components like windows, carpet, and appliances, transportation of materials from raw material extraction to product manufacturing to construction site, and maintenance or improvement of materials. Figure 11. System Boundaries: Top diagram shows system boundary for fluorescent lamps and incandescent lamps taken only • Onsite construction, including site prepara- around disposal of each type of lamp vs. bottom diagram with system boundary around entire life cyle of each type of lamp.

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requirements and the waste and air emissions One source of data for the inventory analysis as an overall effect on the climate, without per square foot could be normalized to this unit is the U.S. Life-Cycle Inventory (LCI) Data- having to model the actual impacts on health in order to compare different paint products.19 base.21 The LCI Database was created by the or ecosystems caused by the changes in the However, the lifetime of the paints would also National Renewable Energy Lab (NREL) and atmosphere.23 need to be considered in the LCA, since the its partners (including the Athena Institute) to lower emissions of one paint product could be help answer questions about environmental Possible impacts to consider in this step offset if it required more frequent reapplication. impact when conducting a LCA.22 The online include: So the functional unit is better defined as one database provides a cradle-to-grave account- square foot for 20 years. This would capture ing of the energy and material flows into and • Land use environmental impacts from the original appli- out of the environments that are associated • Resource depletion cation as well as any reapplications during that with producing a material, component, or • Air quality time frame for both paints. assembly. It contains data on commonly used • Water quality and quantity

In order to compare the existing home to the materials, products, and processes. • Global warming potential from CO2 and desired energy-efficient home, functional units other greenhouse gas emissions such as the following were defined in the For the Michigan home LCA, the majority of • Toxicity to humans, animals, or both Michigan home case study: the energy and GWP data sets were obtained • Energy, including grey or embodied energy from the DEAM software database, which has • Solid waste emissions • Internal/usable floor area: 2,450 ft2. information on a wide range of materials. En- • Stratospheric ozone depletion • Internal usable building volume: 26,960 ft3. ergy-10 was used for energy simulations. The • Smog • Occupancy: 4 people. inventory was then divided into eight home • Acidification • Life span of home: 50 years. systems: walls, roof/ceilings, floors, doors/ • Eutrophication • Basement and garage area: 1,675 ft2 and windows, foundation, appliances/electrical, • Natural resources, including habitat, 484 ft2 respectively. sanitary/HVAC, and cabinets. water, fossil fuels, minerals, and biological • omparable thermal comfort, indoor air resources quality, daylighting, and lighting intensity in Step 3: Impact assessment • Human toxicity both homes. • Ecotoxicity • Municipal supply of potable water. During the third step of the LCA process, • In-home generation of hot water with a called the life cycle impact assessment, the For the Michigan home LCA, only the impacts natural gas boiler. extensive data collected in the LCI step is con- from energy use and global warming potential • In-home heat generation with natural gas verted to indicators for each impact category. were analyzed. furnace; cooling with central air-condition- The indicators correlate to the impacts without After determining the indicators, the impact ing unit. actually measuring them. Thus, climate indicator results can be combined to yield a • Grid-supplied 110-volt electricity change is measured using the global warming single number score. Alternatively, the impact potential of greenhouse gases released into results can be normalized into units that can Step 2: Inventory analysis the atmosphere. In this way, information about be compared more readily to help users put the greenhouse gas releases is combined the results into perspective.24 The second step in a LCA is to inventory the inputs and outputs for all phases of the life cycle based on the system boundaries defined in step one. Inputs may include raw materials and energy, and outputs may consist of products, solid wastes, wastewater discharges and air emissions. This step, known as the life cycle inventory (LCI), is shown conceptu- ally in Figure 12. It usually takes the most time and effort, since it involves collecting data to quantify all of the inputs and outputs, allocate energy and material flows, validate the data for the specific system, refine the system boundaries, normalize data to the functional unit selected, and creating tables or graphs for use in the next step: impact assessment.

Challenges in this LCI step include tracking material flows, allocating material and energy usage and emissions, and achieving a hig level of data aggregation. For example, the LCI for the production of ethylene, a chemical used in the production of other chemicals such as ethylene oxide, would require gathering data on all the input and output material flows, fuels used as feedstock, fuels used for energy, other feedstock, raw materials, air emissions, Figure 12: Life Cycle Inventory (LCI) for a Building water emissions, and solid waste generation.20

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Among the possible impacts listed above, sions. It is not uncommon to end up with The total life cycle energy for the energy-effi- one deserves particular attention: energy, in alternatives that are not clearly differentiated cient home, compared to the standard home, particular grey and embodied energy. The in terms of their environmental impacts. How- is depicted in Figure 14. It has been broken terms “grey energy” and “embodied energy” ever, the results can still be helpful in gaining a down into three stages: (1) the pre-use phase, are sometimes used interchangeably; how- greater understanding of the potential impacts, which included all the embodied energy of ever, grey energy is properly used to refer to thus suggesting a path to a different alterna- construction and maintenance/improvement the energy required for transporting building tive or supplying enough information to weigh materials, (2) the use phase, which included materials (Fig. 13) and can either be consid- the alternatives in light of other factors such as all of the energy for operating and maintaining ered as separate from the embodied energy geographic or spatial considerations. the home over 50 years, and (3) the demolition or as a component of embodied energy.25 phase, which included all of the demolition and According to a report by the U.S. Department For the Michigan home, employing energy transportation energy. The chart shows that of Energy (DOE), “Embodied energy is the efficiency strategies and materials with lower the majority of the energy consumption occurs energy required for extraction or harvesting embodied energy, reduced the pre-use phase in the use phase as compared to the pre-use of raw materials and manufacturing the raw energy by 3.9% while use-phase energy (embodied energy) and demolition phases. materials into products for buildings. Some (space and water heating, lighting, plug loads, definitions of embodied energy also include and embodied energy of maintenance and im- LCA tools the energy required for transporting a material provement materials) was reduced by 67.4%. to the construction site, but the embodied en- The total energy consumption and the GWP Many building sector websites provide general ergy research performed by DOE’s Industrial for the energy efficient home were decreased information on LCA and include lists of LCA Technologies Program focuses on extraction by 63% compared to the standard home. tools and other resources. For example, the and/or manufacturing processes.” Overall, the total life cycle energy was reduced United States Green Building Council (US- by a factor of 2.73, and life cycle GWP by a GBC) website provides a list of links to “Life Step 4: Interpretation factor of 2.71. Cycle Analysis and Costing” resources.27

During the fourth step of the LCA, the results The most significant difference was the 12” However, a review of articles, reports and of the impact assessment are reviewed for thick, R-35 walls (filled with cellulose insula- online resources that assess LCA tools leads appropriateness, completeness, and accuracy. tion) that were used on the energy efficient to many resources but no one coherent They are then interpreted to provide guid- homes. Using cellulose, which has less method for navigating the LCA world. Based ance to the LCA users on how to use the LCA embodied energy and thus lowered the energy on the literature review for this paper, a good results for improving environmental perfor- for the pre-use phase, increased the thermal place to search for a LCA tool for a building or mance.26 It is likely that the LCA process will resistance of the wall by a factor of three. building components would be the IEA Annex require estimates and assumptions, which will Combined with doubling the insulating value in 31, “Directory of Tools: A Survey of LCA Tools, likely include making value judgments. Any the ceiling, this greatly improved the perfor- Assessment Frameworks, Rating Systems, such estimates, assumptions, and value judg- mance of the thermal envelope for the energy Technical Guidelines, Catalogues, Checklists ments should be communicated in the final efficient home. and Certificates”28 results and considered when drawing conclu- The Annex 31 Directory of Tools provides a quick overview of current tools in terms of their functions, audience, users, software applications, technical support, data requirements, strengths, availability, and contact information. The directory, which is designed to comple- ment the U.S. DOE Office of Energy Efficiency and Renewable Energy (EERE) “Building Energy Software Tool Directory”, lists tools in 13 countries including several in the U.S.29 The directory separates the tools into five types: Energy Modeling Software, Environmental LCA Tools for Building or Building Product, En- vironmental Assessment Frameworks, Rating Systems (Whole Buildings or Building Stocks), Environmental Guidelines or Checklists for Building Design/Management, and Envi- ronmental Product Declaration, Catalogue, Reference Information, Certification, Label. Of these five categories, the last three are comprised of what Annex 31 refers to as “pas- sive tools”, which they think are best suited for decision support and are best applied “within the fast-paced processes involving design professionals.”30 However, if more sophisticat- ed tools are required, the U.S. DOE Building

Figure 13: Embodied or grey energy related to transportation Energy Software Tool Directory referenced in the Annex 31 Directory of Tools appears to be

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Other LCA Case Studies

Below are summaries of two other LCA case studies: LCA applied to a building (a stadium) and LCA applied to a building enclosure (wall and roof materials).

Case Study 1: The Olympic Stadium in Aus- tralia33

A software tool created by the NSW Depart- ment of Public Works and Services (DPWS) based on the Boustead 3 model, but using Australian data, was used to perform a LCA analysis of three designs – a conventional stadium design, a better environmental practice design, and a best practice design. The results were analyzed and the better environmental practice design chosen. The LCA was used to evaluate and select the materials as well as the energy and water consumption, which resulted in a stadium design with reduced environmental impacts that became a bench- mark for other stadium projects. The improved Figure 14: Total Life Cycle Energy for Michigan Home Case Study design provided an annual primary energy savings of 30%, a 37% reduction in greenhouse gas emissions, and a 13% reduction in water use, with 77% of water coming from a good resource. 31 tool directory described above. The other is onsite recycling or onsite water collection. a simple three-level classification for LCA tools The U.S. DOE Building Energy Software Tool created by the Athena Institute, a non-profit Case Study 2: Single-Story Houses in Indo- Directory is an online directory which provides organization that seeks to improve the sustain- nesia34 information on over 300 building software ability of the built environment: tools, including databases, spreadsheets, and A LCA was conducted on the enclosures of simulation programs for evaluating energy • Level 1 - product comparison tools and single-story houses, the typical building type efficiency, renewable energy, and sustainability information sources in Indonesia. The study revealed that the initial in buildings. The tools can be listed alphabeti- • Level 2 - whole building design or deci- embodied energy of a typical brick and clay cally, by platform (Mac, PC, Unix or Internet), sion support tools roof enclosure was 1gigajoule (GJ) more than by country or by subject. The directory list • Level 3 - whole building assessment that for other typical wall and roof material includes tools for whole building analysis of frameworks or systems. (cement based). However, over the 40-year energy simulation, load calculation, renewable life span of the houses, the clay-based houses energy, retrofit analysis, and sustainability/ A fourth category includes supporting tools demonstrate better energy performance than green buildings, as well as tools for materials, and techniques, such as Baseline Green, the cement-based ones. This led to the conclu- components, equipment and other applica- developed by Pliny Fisk and Greg Norris of sion that material selection during the design tions. Furthermore, the directory includes a The Center for Maximum Potential Build- phase is crucial, since the buildings have a short description along with information on ing Systems in Austin, Texas.32 To facilitate lifespan of at least 40 to 50 years. expertise required, users, audience, input, comparison of tools, the authors combined the output, computer platform, programming lan- two classification systems, using the Athena Conclusions guage, strengths, weaknesses, contacts, and system as the basis since it categorizes the 30 availability for each tool. assessment tools according to where they are LCAs have demonstrated benefits in evaluat- used in the assessment process and for what ing overall material and energy efficiency as The majority of these applications can be used purpose, which facilitates comparing tools well as benchmarking efficiency improvements for life cycle assessment as well as related within levels. and emission reductions. Architects, design- material and energy analyses applicable to the ers, builders, building product manufactur- built environment. However, further information The 13 LCA tools were listed according to level ers, and others in the building design and on any of the applications, such as exper- and were compared in terms of the types of construction profession have access to LCA tise required, requires going to a separate buildings to which they could be applied. The software programs, standards, and guid- webpage for each application, which makes study concluded that comparing LCA tools is ance documents to help guide their decisions comparing the tools somewhat cumbersome. a difficult task since each tool is designed dif- when designing, operating, maintaining and/ A recent study, published in Environmental ferently, relying on different databases, with an or remodeling buildings. However, navigating Impact Assessment Review, analyzed and emphasis on different life cycle phases, aimed the available LCA tools is not a straightforward 31 categorized thirteen LCA tools. According to at assessing different types of buildings. task. A few tools, such as the IEA Annex 31 the study, there are two well-known classifica- Directory of Tools and the U.S. DOE’s Building tion systems for LCA tools. One is the Annex

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Energy Software Tool Directory can be help- Finland, France, Germany, Japan, Neth- LCA-yardstick.html. ful in selecting the right tools for the various erlands, New Zealand, Norway, Sweden, 16 Blanchard, Steven and Peter Reppe, components and life cycle stages. Studies Switzerland, United Kingdom and United 1998. “Life Cycle Analysis of a Resi- have been, and will continue to be, conducted States of America). Canada served as the dential Home in Michigan”, A project to assess and compare the various LCA tools. coordinating agency for the project. submitted in partial fulfillment of require- The results of such studies can be helpful in 6 Kohler, Niklaus and Sebastian Moffatt, ments for the degree of MS of Natural navigating the available tools to determine the 2003. “Life-cycle analysis of the built envi- Resources at the University of Michigan, best options. ronment”, UNEP Industry and Environ- Sponsored by the National Pollution Pre- ment, April-September 2003, pp. 17-21. vention Center, October 1998, http://www. As LCA tools continue to undergo improve- 7 Owens, J.W., 1997. “Life Cycle As- umich.edu/~nppcpub/research/lcahome/. ments and inventory data continues to be sessment: Constraints on Moving from 17 Rosselot, Kirsten and David T. Allen, generated and refined, system boundaries and Inventory to Impact Assessment”, Journal 2001. “Life-Cycle Concepts, Product functional units must be carefully selected. of Industrial Ecology, Volume 1, Number Stewardship and Green Engineer- Furthermore, the results should be used 1, Massachusetts Institute of Technology ing”, Chapter 13 in Green Engineering: judiciously. When there is doubt as to the best and Yale University. Environmentally Conscious Design of alternative, options can be considered in terms 8 Ibid Chemical Processes, D. T. Allen and of the local, cultural, social, and economic 9 National Renewable Energy Lab, U.S. D. Shonnard, Prentice Hall, Englewood context, or the analysis can be extended to Life Cycle Inventory Database, http:// Cliffs, http://www.utexas.edu/research/ include other components that could provide www.nrel.gov/lci/assessments.html. ceer/greenproduct/dfe/chap13.htm. an even more holistic assessment. 10 McDonough, William and Michael Braun- 18 Ibid gart, 2002, Cradle to Cradle: Remaking 19 Ibid In spite of concerns and challenges, LCA the Way We Make Things, New York: 20 Owens, J.W., 1997. “Life Cycle As- continues to help shape emerging green North Point Press, pp. 103-104. sessment: Constraints on Moving from building technology, in particular with regard 11 Schenck, Rita, 2002. “Life Cycle Assess- Inventory to Impact Assessment”, Journal to assessing energy use and global warm- ment: the Environmental Performance of Industrial Ecology, Volume 1, Number ing potential in order to address these in the Yardstick”, American Center for Life Cycle 1, Massachusetts Institute of Technology design phase. LCA practitioners and users Assessment, Institute for Environmental and Yale University. are gaining greater expertise in combining Research and Education, Produced for 21 National Renewable Energy Lab, U.S. LCA with other assessment tools and using Earthwise Design, Life Cycle Assessment Life Cycle Inventory Database, http:// the results to support their decisions to lower Realities and Solutions for Sustainable www.nrel.gov/lci/, http://www.nrel.gov/lci/ environmental impacts or even to improve Buildings January 19th 2002, Antioch database/. upon current conditions through regenerative University, http://www.lcacenter.org/LCA/ 22 NREL is a national laboratory of the U.S. or restorative design. LCA-yardstick.html. Department of Energy, Office of En- 12 Highlight Report of Annex 31 - Energy- ergy Efficiency and Renewable Energy, Related Environmental Impact of operated by the Alliance for Sustainable Notes Buildings, a project established under Energy, LLC. the auspices of the International Energy 23 Rosselot, Kirsten and David T. Allen, 1 The Institute for Market Transformation Agency’s (IEA) Energy Conservation in 2001. “Life-Cycle Concepts, Product to Sustainability, http://www.sustain- Buildings and Community Systems Pro- Stewardship and Green Engineer- ableproducts.com/mts/about.htm#join. gramme, p. 8., http://www.greenbuilding. ing”, Chapter 13 in Green Engineering: 2 U.S. Green Building Council, http:// ca/annex31/Main/highlight_report.htm. Environmentally Conscious Design of www.usgbc.org/DisplayPage. 13 Malin, Nadav, 2002. “Life-Cycle As- Chemical Processes, D. T. Allen and aspx?CMSPageID=1718. sessment for Buildings: Seeking the D. Shonnard, Prentice Hall, Englewood 3 U.S. DOE/Energy Efficiency and Renew- Holy Grail, Feature from Environmental Cliffs, http://www.utexas.edu/research/ able Energy, “Chapter 1.1 Buildings Sec- Building News”, March 1, 2002, http:// ceer/greenproduct/dfe/chap13.htm. tor Energy Consumption”. In Buildings www.buildinggreen.com/auth/article. 24 Schenck, Rita, 2002. “Life Cycle Assess- Energy Data Book (September 2008), cfm?fileName=110301a.xml. ment: the Environmental Performance http://buildingsdatabook.eren.doe.gov/ 14 Life Cycle Assessment: Principles Yardstick”, American Center for Life Cycle ChapterView.aspx?chap=1#1. and Practice by Scientific Applica- Assessment, Institute for Environmental 4 Haapio, Appu, and Pertti Viitaniemi, 2008. tions International Corporation (SAIC), Research and Education, Produced for “A critical review of building environmen- EPA/600/R-06/060, May 2006, http:// Earthwise Design, Life Cycle Assessment tal assessment tools”, Environmental www.epa.gov/ORD/NRMRL/lcaccess/ Realities and Solutions for Sustainable Impact Assessment Review 28, no. 7: pp. pdfs/600r06060.pdf. Buildings January 19th 2002, Antioch 469-482. Environment Index, EBSCOhost 15 Schenck, Rita, 2002. “Life Cycle Assess- University, http://www.lcacenter.org/LCA/ (accessed October 15, 2008). ment: the Environmental Performance LCA-yardstick.html. 5 Annex 31, Energy related environmental Yardstick”, American Center for Life Cycle 25 Presas, Luciana Melchert Saguas, 2005. impact of buildings”, is a project estab- Assessment, Institute for Environmental Transnational Buildings in Local Environ- lished under the auspices of the IEA Research and Education, Produced for ments, England: Ashgate Publishing, Ltd., Energy Conservation in Buildings and Earthwise Design, Life Cycle Assessment p. 42. Community Systems Programme in Realities and Solutions for Sustainable 26 Schenck, Rita, 2002. “Life Cycle Assess- Canada, in which fourteen countries par- Buildings January 19th 2002, Antioch ment: the Environmental Performance ticipated (Australia, Canada, Denmark, University, http://www.lcacenter.org/LCA/ Yardstick”, American Center for Life Cycle

11 II-Strategies Analysis

Assessment, Institute for Environmental Figure 6: Conrete plant: http://farm1.static. annex31/index.html Research and Education, Produced for flickr.com/99/302360315_79defcc208.jpg?v=0. Earthwise Design, Life Cycle Assessment Sustainable Building Information System: Realities and Solutions for Sustainable Figure 7: Building materials (bricks): http:// http://www.sbis.info/index.jsp Buildings January 19th 2002, Antioch www.rics.org/NR/rdonlyres/A5D348DB-F006- University, http://www.lcacenter.org/LCA/ 454A-8466-124DEAD9BC7B/0/bricks.png. UNEP Life Cycle Initiative: http://jp1.estis.net/ LCA-yardstick.html. sites/lcinit/default.asp?site=lcinit 27 See list of LCA and LCC links on the Figure 8: Under construction: http://www.sxc. USGBC website at: http://www.usgbc.org/ hu/photo/958918. U.S. DOE Buildings Energy Data Book: http:// DisplayPage.aspx?CMSPageID=76. buildingsdatabook.eren.doe.gov/ChapterView. 28 Available for download at: http://www. Figure 9: Coal miing: http://upload.wikimedia. aspx?chap=1 greenbuilding.ca/annex31/Main/dir_tools. org/wikipedia/commons/b/b3/Strip_coal_min- htm. ing.jpg Whole Building Design Guide: http://www. 29 U.S. DOE/Energy Efficiency and Renew- wbdg.org/tools/tools_cat.php?c=3 able Energy, Building Technologies Figure 9: Power lines: http://www.sxc.hu/ Program, Building Energy Software Tool photo/1075609. Directory, http://apps1.eere.energy.gov/ Biography buildings/tools_directory/. Figure 10: Demolition of Chemistry Building 30 “Types of Tools”, Core report to Annex 31: at The University of Texas at Austin, by Dr. Dr. David T. Allen is the Gertz Regents Profes- Energy-Related Environmental Impact of Werner Lang sor of Chemical Engineering, the Director Buildings, p. 2, http://www.greenbuilding. of the Center for Energy and Environmental ca/annex31/pdf/D_types_tools.pdf. Figure 11: From Chapter 13 in Green Engi- Resources, and the Director of the Energy In- 31 Haapio, Appu, and Pertti Viitaniemi, 2008. neering: Environmentally Conscious Design stitute at the University of Texas at Austin. He “A critical review of building environmen- of Chemical Processes, by D. T. Allen and D. is the author of six books, including a textbook tal assessment tools”, Environmental Shonnard, Prentice Hall, Englewood Cliffs, on the design of chemical processes and prod- Impact Assessment Review 28, no. 7: pp. 2001, online at http://www.utexas.edu/re- ucts that was jointly developed with the U.S. 469-482. Environment Index, EBSCOhost search/ceer/greenproduct/dfe/PDF/Chap13fi- EPA, and over 170 papers in areas ranging (accessed October 15, 2008). nal.PDF from coal liquefaction and heavy oil chemistry 32 Fisk, Pliny and Greg Norris, “Building to the chemistry of urban atmospheres. GreenTM – A Green Building Design Figure 12: Developed for this paper by Elena Methodology”, The Center for Maximum Rivera Urban air quality and the development of Potential Building Systems, http://www. materials for environmental education have cmpbs.org/publications/T1.7-Baseline- Figure 13: Truck transporting logs, at http:// been the primary focus of his work for the past Green.pdf. www.sxc.hu/pic/m/r/re/renaudeh/1019695_log- decade. Dr. Allen was a lead investigator for 33 Greening the Building Life Cycle, http:// ging_truck.jpg. the first two Texas Air Quality Studies, which buildlca.rmit.edu.au/menu9.html. involved hundreds of researchers from around 34 Utama, Agya and Shabbir H. Gheewala, the world, and which have had a substantial 2008. “Life cycle energy of single landed Resources impact on the direction of air quality policies in houses in Indonesia”, Energy & Buildings; Texas. He has also developed environmental Oct2008, Vol. 40 Issue 10, p1911-1916. Architecture 2030: http://www.architec- education materials for engineering curricula ture2030.org/ and for the core curriculum of the University of Texas. His quality work was recognized Figures Building Green: http://www.buildinggreen.com/ by the National Science Foundation through the Presidential Young Investigator Award, Figure 1: Tokyo buildings: http://farm1.static. Energy Star: http://www.energystar.gov/ the AT&T Foundation through an Industrial flickr.com/21/30259947_cc46aaca0d.jpg?v=0. Ecology Fellowship, the American Institute of EPA, Life Cycle Assessment: Principles and Chemical Engineers through the Cecil Award Figure 2: Based on U.S. Energy Information Practice: http://www.epa.gov/nrmrl/lcaccess/ for contributions to environmental engineering, Administration statistics per Architecture 2030 lca101.html and the State of Texas through the Governor’s source at http://www.architecture2030.org/ Environmental Excellence Award. building_sector/index.html Green Building Initiative website: http://www. thegbi.org/commercial/life-cycle-assessment. Dr. Allen received his B.S. degree in Chemi- Figure 3: Construction waste at http://www. asp cal Engineering, with distinction, from Cornell inhabitat.com/wp-content/uploads/pvc.jpg. University in 1979; and his M.S. and Ph.D. Green Product and related website, Dr. David degrees in Chemical Engineering from the Figure 4: Life Cycle Analysis of a Building, T. Allen, University of Texas at Austin, Depart- California Institute of Technology in 1981 and from INTRON website at http://www.intron.nl/ ment of Chemical Engineering: http://www. 1983, respectively. He has held visiting faculty site_eng/thema_lca.aspx. utexas.edu/research/ceer/greenproduct/ appointments at the California Institute of Technology, the University of California, Santa Figure 5: Based on figure by David T. Allen, Healthy Building Network: http://www.healthy- Barbara, and the Department of Energy. Life Cycle Assessment Overview, online at building.net/index.html http://www.utexas.edu/research/ceer/greenproduct/pages/life_cycle_assessment_er.htm. IEA Annex 31: http://www.greenbuilding.ca/

12 2.15 Life Cycle Assessment for Buildings