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Materials Matter - Construction Materials and their Environmental Costs

This presentation will show how the life cycle assessment makes it easier for architects to incorporate environmental considerations into their building material selection. It will discuss the life cycle impacts of wood, concrete and steel and demonstrate that over its life cycle, wood is better for the environment than steel or concrete in terms of embodied energy, air and water pollution and greenhouse gas emissions. In addition, this presentation will highlight the advances each industry is making toward sustainability.

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Materials Matter - Construction Materials and their Environmental Costs

  1. 1. The design community has for many years sought to create buildings that are energy efficient, better for the environment and healthier for occupants. This has been the driving force behind the modern green building movement, but actually goes back to the energy crisis of the 1970s—when (Part 1 of a 3 sharply rising oil prices provided all the part incentive people needed to reduce fossil fuel consumption. Materials Matter series) Construction Materials and Environmental Costs Today, concern about the effects of carbon dioxide and other greenhouse gases has given the movement a reinvigorated sense of urgency … and expanded the focus to include, not only energy use, but the resulting carbon impacts of buildings. Materials Matter Construction Materials and Environmental Costs (Part 1 of a 3-part series) Photo courtesy of
  2. 2. ‘’Materials Matter’’ CEU Series Overview Materials Matter (Part 1) Materials in Action (Part 2) “Materials Matter” CEU Series Overview Materials Matter (Part 1) Materials in Action (Part 2) This presentation is part one in a three-part series, based on a CEU, Materials Matter, first published in Architectural Record in 2011. Some of the statistics have been updated based on new information. • “Materials Matter” (Part 1 of 3) documents the environmental footprint of wood, concrete, and steel. • “Materials in Action” (Part 2 of 3) covers their performance during construction, operation and end-of-life, reaffirming that in the quest for carbon-neutral buildings, materials do mat“A • Natural Choice” (Part 3 of 3) covers how these materials factor into green design and high-performance buildings as well as how green design projects are currently defined. This presentation will address the overt differences between three common materials—wood, steel and concrete—and their life cycle environmental impacts. These materials will also be discussed in terms of responsible procurement, sustainability and community issues. A Natural Choice (Part 3) A Natural Choice (Part 3)
  3. 3. Copyright Materials This presentation is protected by U.S. and international copyright laws. Reproduction, distribution, display and use of the presentation without written permission of reThink Wood is prohibited. © 2013, reThink Wood,
  4. 4. Learning Objectives  Discuss life cycle impacts of wood, concrete and steel.  Explain recyclability vs. renewability for each.  Describe responsible procurement.  Explain the advances each industry is making toward sustainability. Photo Source (in order):, dreamstime, dreamstime More specifically, this presentation will show how life cycle assessment is making it easier for designers to incorporate environmental considerations into their decision making. It will demonstrate that, when viewed over its life cycle, wood is better for the environment than steel or concrete in terms of embodied energy, air and water pollution and greenhouse gas emissions. And it will highlight other benefits of wood such as recyclability and renewability, a light carbon footprint, third-party certification and chain of custody.
  5. 5. Table of Contents Section 1 Materials Matter Section 2 Life Cycle Assessment Section 3 Manufacturing Section 4 Transportation Section 5 Renewable Versus Recyclable Section 6 Responsible Procurement
  7. 7. Every design and building professional knows the building sector has a significant impact on the environment, but it may surprise you to know the extent. For example, the building industry uses more than 3 billion tons of materials a year worldwide, and accounts for 40 percent of the world’s raw materials. Buildings also consume 30-40 percent of the world’s energy. Clearly there is a need—and an opportunity—to construct buildings in a way that reduces their environmental impact. Sources: Bullets 1 and 2 – D.M. Roodman and N. Lenssen, A Building Revolution: How Ecology and Health Concerns are Transforming Construction, p. 5., Worldwatch Paper 124, Worldwatch Institute, Washington, D.C., March 1995 Bullet 3 – Buildings and climate change: Status, challenges and opportunities, p.4-7, United Nations Environment Programme, 2007. ateChange.pdf The Building Industry Worldwide:  3 billion tons of materials a year  40% of raw materials  30-40% of total energy Worldwatch Institute; United Nations Environment Programme Photo: dreamstime
  8. 8. Building Green: Driving by Need Faced with these realities, the architecture and construction industries have been making significant efforts to lighten the environmental footprint of tomorrow's structures. This goal is particularly pressing in light of the fact that 1.6 billion square feet are added each year in the commercial building sector alone. That's nearly 110,000 buildings annually at the mean size of 14,700 square feet or roughly half a million buildings every five years. Source: Energy Efficiency Trends in Residential and Commercial Buildings, US Department of Energy, 2008 Photo: Magnus L3D Wikipedia United States:  Each year, 1.6 billion sf added to commercial building sector: - 110,000 buildings (mean size of 14,700 sf) - Half a million buildings every five years Source: U.S. Department of Energy Photo Magnus L3D Wikipedia
  9. 9. Until now, the main focus of building green has been operational energy efficiency— and considerable strides have been made both in terms of improving the building envelope and otherwise reducing energy consumption. So much so that designers are now looking beyond operational energy to the embodied and end-of-life impacts of their building materials. Building green includes embodied, operational and end-of-life impacts. Most material choices ignore impacts of manufacture, maintenance and disposal. Environmental costs of production are not fully acknowledged. Materials Make a Difference Building green includes embodied, operational and end-of-life impacts.  Most material choices ignore impacts of manufacture, maintenance and disposal.  Environmental costs of production are not fully acknowledged. Photo: iStock (stock)
  11. 11. There’s been a tendency to look for simple answers to very complex questions. There is no perfect material, so we need to understand trade-offs in terms of real environmental effects. -- Athena Sustainable Materials Institute “ “ The information we’re looking for has layers and layers of complexity. In the past, the green building movement has taken a prescriptive approach to choosing building materials. This approach assumes that certain “prescribed” practices are better for the environment regardless of their manufacturing process or disposal issues. One example is recycled content: most green building rating systems reward steel with recycled content over wood products that, not only require far less energy to produce, but result in considerably less greenhouse gas emissions, air pollution and water pollution. Locally produced materials are another example. In most green building rating systems, materials produced within 500 miles of the job site are rewarded regardless of their manufacturing process or end-of-life disposal. The prescriptive approach is overly simplistic and can lead designers to incorrect assumptions … which is why, increasingly, it is being replaced by the scientific evaluation of estimated impacts through life cycle assessment, or LCA.
  12. 12. Life Cycle Assessment (LCA)  Scientific method for evaluating environmental impacts - Products - Materials - Assemblies - Whole buildings  Internationally recognized, defined in ISO 14040  Allows objective comparison of alternate building designs; encourages environmental decision making LCA is an internationally recognized method for evaluating the environmental impacts of products, materials, assemblies or even whole buildings over their entire lives. Defined by the International Organization for Standardization (ISO), it is an objective way of quantifying and interpreting the energy and material flows to and from the environment. The analysis includes emissions to air, water and land, as well as the consumption of energy and material resources.
  13. 13. LCA for Building Products  Analysis covers extraction or harvest of raw materials through eventual demolition and disposal or reuse. In a building context, LCA considers a full range of impacts from the extraction or harvest of raw materials through manufacturing, transportation, installation, use, maintenance and disposal or recycling. Internationally, the United Nations Environment Programme has been promoting LCA for more than a decade. It is more common in Europe than North America, but its use is increasing in both markets because of its holistic approach and power as an evaluative tool. . Source: Building Green With Wood
  14. 14. For building professionals: Athena Impact Estimator for Buildings BEES m LCA Tools For LCA practitioners: GaBi SimaPro Because calculating life cycle impacts is complex and time consuming, tools exist to help architects judge the environmental merits of various materials and building assemblies. In North America, the Athena Impact Estimator is the only software tool designed to evaluate whole buildings and assemblies based on internationally recognized LCA methodology. Developed by the Athena Sustainable Materials Institute, it allows building designers and others to easily assess and compare the environmental implications of industrial, institutional, commercial and residential designs—both for new buildings and major renovations. The impact estimator is available as a free download. ENVEST BEES is a free, U.S.-based tool for product-to-product comparisons. It was developed by the National Institute of Standards and Technology, and results are based on proprietary, unpublished data. Envest is a UK-based, LCA-based building design tool. It addresses only the whole building and provides results in highly summarized “ecopoints.” The Forest Industry Carbon Assessment Tool (FICAT) calculates carbon footprints of the effects of forest-based manufacturing activities on carbon and greenhouse gases along the value chain. It’s a joint venture of the National Council for Air and Stream Improvement and the International Finance Corporation and is available as a free download. Forest Industry Carbon Assessment Tool Just as there are different LCA tools for building professionals, there are different tools intended for use by LCA practitioners. GaBi is a tool from Germany, comprised of primarily European data. SimaPro is a tool from the Netherlands. It includes a comprehensive suite of databases for building materials applicable to the United States, Japan and various European countries.
  15. 15. LCA and Wood  Wood outperforms other materials in terms of embodied energy, air and water pollution, and greenhouse gas emissions. LCA studies consistently demonstrate wood’s environmental advantages over steel and concrete when it comes to embodied energy, air and water pollution, global warming potential and other environmental impact indicators.1 In this graph, three hypothetical homes (wood, steel and concrete) of identical size and configuration are compared. Assessment results are summarized into six key measures during the first 20 years of operating these homes. The wood home outperformed the others in terms of air pollution, embodied energy, global warming potential (or greenhouse gases) and water pollution. It performed comparably to steel and better than concrete in terms of solid waste and resource use. Source: Data compiled by the Canadian Wood Council using the ATHENA EcoCalculator with a data set for Toronto, Canada, 2004; Green Building with Wood Toolkit, LCA, 1Werner, F. and Richter, K. 2007. Wooden building products in comparative LCA: A literature review. International Journal of Life Cycle Assessment, 12(7): 470-479. Source: Data compiled by the Canadian Wood Council using the ATHENA EcoCalculator with a data set for Toronto, Canada
  16. 16. Comparing Wall Assemblies (CORRIM STUDY, 2005) Minneapolis House Wood Frame Steel Frame Difference A landmark study conducted by the Consortium for Research on Renewable Industrial Materials (CORRIM) also compared wood-frame and concrete homes in the hot climate of Atlanta and wood and steel-frame homes in the cold climate of Minneapolis—the framing types most common to each city. Among other things, the global warming potential of the steel and concrete homes were 26 and 31 percent higher, respectively, than the wood-frame homes. This chart focuses on the wall assemblies only and shows that the steel and concrete assemblies had 80 percent and 38 percent higher global warming potential than the wood assembly. Source: Life Cycle Environmental Performance of Renewable Building Materials in the Context of Residential Construction – Phase I, 2005 - Steel vs. Wood (% change) Embodied energy (GJ) 250 296 46 18% Global warming potential (CO2 kg) 13,009 17,262 4,253 33% Air emission index (index scale) 3,820 4.222 402 11% Water emission index (index scale) 3 29 26 867% Solid waste (total kg) 3,496 3,181 -315 -9% Atlanta House Wood Frame Steel Frame Difference Steel vs. Wood (% change) Embodied energy (GJ) 168 231 63 38% Global warming potential (CO2 kg) 8,345 14,982 6,637 80% Air emission index (index scale) 2,313 3,372 1,060 46% Water emission index (index scale) 2 2 0 0% Solid waste (total kg) 2,325 6,152 3,827 164%
  17. 17. The Carbon Connection The building sector consumes more energy than any other sector. Most of this energy is produced from burning fossil fuels, making this sector the largest emitter of greenhouse gases on the planet. Many people believe we are heading toward irreversible climate change and, as a result, are placing an increasing emphasis on reducing the carbon footprint of buildings. Architect Michael Green believes that, to reduce carbon footprint, we need to consider the impacts associated with different building materials and choose wisely. The building pictured here is the Prince George Airport, an expansion of which was designed by Mr. Green’s architectural firm, Michael Green Architecture. Glulam and glass were used to create a design that’s architecturally stunning while integrating new and existing parts of the building. As architects, we have to ask ourselves: Is there a material that minimizes or eliminates carbon in the environment? -- Michael Green, MAIBC, AIA, MRAIC Michael Green Architecture “ “ Prince George Airport British Columbia Architect: mgb Photo: mgb
  19. 19. Manufacturing Energy and CO2 The manufacturing of materials requires the greatest amount of energy in the entire construction process. The manufacturing of materials requires the greatest amount of energy in the entire construction process. When it comes to material selection and carbon, embodied energy is a key part of the equation. How much energy does it take to extract, process, manufacture, transport, construct and maintain a material or product—and what is the impact of that energy in terms of greenhouse gas emissions? When the construction process is viewed as a whole, the manufacturing of materials is the most energy intensive. Photos (in order): dreamstime (stock), dreamstime, Photos (in order): dreamstime (stock), dreamstime,
  20. 20. From an energy perspective, an advantage of wood is that it’s produced naturally. Compared to steel and concrete, wood products don’t need much processing, so the manufacturing phase requires far less energy and results in far less carbon dioxide emissions. This has been demonstrated time and time again in LCA studies. Another advantage is that more than half the energy that is required to produce wood products comes in the form of renewable biomass. It’s common for companies to have cogeneration facilities, also known as combined heat and power, which convert sawdust, bark and other residual fiber to electrical and thermal energy. The electricity is used to power equipment. Photos: Sources: Bullet 2 – Synthesis of Research on Wood Products and Greenhouse Gas Impacts, Sarthre, R. and J. O’Connor, 2010, FPInnovations; Wooden building products in comparative LCA: A literature review, Werner, F. and Richter, K., 2007, International Journal of Life Cycle Assessment, 12(7): 470-479 Bullet 3 –AF&PA Environmental, Health & Safety Verification Program – Biennial Report and Improve Energy Efficiency fact sheet, 2012; The State of Canada's Forests Report – 2012 Wood Manufacturing  Wood is produced naturally and is renewable.  Manufacturing requires less energy than other materials—and results in less CO2 emissions.  Most of the energy comes from residual fiber such as bark and sawdust left over after lumber and paper making. Photos:
  21. 21. Lumber Manufacturing A mill for producing lumber is relatively straightforward. Once the bark is removed, logs are sawn and trimmed to precise lengths, dried, and then planed, grade-stamped and packaged. Photos:
  22. 22. Carbon Storage In addition to LCA, another environmental aspect to consider is the fact that trees and forest products can help to minimize our carbon footprint over the long term. In terms of wood’s positive impact on a building’s carbon footprint, there are several elements to consider: 1) As trees grow, they clean the air we breathe by absorbing carbon dioxide from the atmosphere, storing the carbon in their wood, roots, leaves or needles, and surrounding soil, and releasing the oxygen back into the atmosphere. Young, vigorously growing trees absorb the most carbon dioxide, with the rate slowing as they reach maturity. 2) When trees start to decay, or when forests succumb to wildfire, insects or disease, the stored carbon is released back into the atmosphere. However, when trees are harvested and manufactured into forest products, the products continue to store much of the carbon. In the case of wood buildings, this carbon is kept out of the atmosphere for the lifetime of the structure—or longer if the wood is reclaimed and manufactured into other products. 3) In any of these cases, the carbon cycle begins again as the forest is regenerated, either naturally or by planting, and young seedlings once again begin absorbing carbon. 4) Manufacturing wood into products requires far less energy than other materials—and very little fossil fuel energy. Most of the energy that is used comes from converting residual bark and sawdust to electrical and thermal energy, adding to wood’s light carbon footprint. Photos: (right), W.G. Clark Construction/Mahlum (left) Source for Bullet 2: FPInnovations  Forests absorb and store carbon  The wood in buildings is about 50% carbon by dry weight  Recycled and reclaimed wood continues to store carbon Photo: W.G. Clark Construction/Mahlum Photo:
  23. 23. More Wood = Lighter Carbon Footprint Increasing emphasis on carbon footprint is one of the reasons wood buildings are getting taller—along with wood’s safety and performance record and innovative new products such as cross laminated timber, or CLT, which offer exceptional strength and dimensional stability. The Forté in Melbourne, Australia includes 10 stories of CLT and, at the time of construction, was the world’s tallest modern wood building. Designing the structure in wood allowed the developer to create “as close to a net zero carbon building as possible.” Between the carbon sequestered in the wood itself and the greenhouse gas emissions avoided by not using steel or concrete, Lend Lease estimates that Forté kept approximately 1,450 metric tons of carbon dioxide (equivalent) out of the atmosphere. In the UK, eight-story Bridport House is the first high-rise in the UK built entirely in CLT, including the ground floor. According to calculations by Stora Enso, each of the 41 apartment units contain 30-40 cubic metres of timber (approximately 1,000-1,400 cubic feet), which is equivalent to more than 30 metric tonnes (33 tons) of carbon dioxide. (Source: Stora Enso) Likewise, a company in Austria has developed a hybrid, wood-based building system for what it calls Life-Cycle Towers, which can be up to 30 stories high and reduce the building’s carbon footprint by 90 percent compared to typical structures. (More information: ) In British Columbia reducing carbon footprint was one of the reasons the building code was changed to increase the number of permitted stories in residential wood buildings from four to six.  AU – Forté, 10 stories of wood  UK – Bridport House, 8 stories of wood  Austria – Life-Cycle Tower, hybrid wood-based system up to 30 stories Photo: Forté, Lend Lease
  24. 24. The process to manufacture steel on the other hand is fossil fuel-intensive. Iron smelted from ore contains more carbon than is desirable. To become steel, the iron must be melted at extremely high temperatures and reprocessed to reduce the carbon and to remove silica, phosphorous and sulfur, which weaken steel Energy intensive Iron ore is extracted through open pit mining and heated to extremely high temperatures using fossil fuel energy, usually charcoal or coke. Manufacturing involves reducing carbon in the iron, which also results in CO2 emissions. Sources: Photo: Trinec Iron and Steel Works (Trinecké zelezárny) Steel Manufacturing  Energy intensive  Iron ore is extracted through open pit mining and heated to extremely high temperatures using fossil fuel energy, usually charcoal or coke.  Manufacturing involves reducing carbon in the iron, which also results in CO2 emissions. Photo: Trinec Iron and Steel Works
  25. 25. Steel Manufacturing Process Most modern steel plants use a basic oxygen furnace in which high-purity oxygen blows through the molten pig iron, lowering carbon levels and those of other impurities. Alloys are added at this time to create the desired properties of the steel product. Liquid steel is then cooled as bars or rods and later rolled and flattened into sheets. Source: World Coal Association, Source: World Coal Association
  26. 26. Concrete Manufacturing Typically, a concrete mix is about 10 to 15 percent cement,1 though the amount changes based on required strength and flexibility. While most of concrete’s ingredients are manufactured products themselves or mined materials, it’s the cement that has the highest embodied energy. Source: 1Portland Cement Association Photo: dreamstime (stock) – no commercial use permitted  Cement (made from limestone and sand) is the main ingredient in concrete and has the highest embodied energy.  Usual process involves blasting limestone from surface mines, mixing it with other materials and heating the mixture to extremely high temperatures with coal or natural gas. Concrete plant Vancouver, British Columbia Photo: dreamstime
  27. 27. Cement Production The major ingredient needed for cement is limestone. In most cases, limestone is blasted from surface mines and removed in large blocks to a crusher where it’s mixed with other raw materials. From there, it’s transferred to a rotating furnace and heated to about 2,700 degrees Fahrenheit, powered by coal or natural gas, in order for the materials to coalesce. The mixture is cooled and ground to fine gray powder (cement), which is then transported to its destination by truck, rail or ship. To reduce the carbon footprint of the end product, fly ash, volcanic ash or magnesium oxide are sometimes substituted for a portion of the cement. However, cement manufacturing is still a carbon-intensive endeavour. In Canada, for example, producing one metric tonne of cement (1.1 tons) results in the emission of approximately one metric tonne (1.1 tons) of carbon dioxide and cement manufacturing accounts for 5 percent of anthropogenic global carbon dioxide emissions. Sources of data: EcoSmart Concrete:; SOS: An Optimization System for the Sustainable Use of Supplementary Cementing Materials in Concrete, 2006,; International Energy Agency, Technology Roadmap – Cement,,3861,en.html
  28. 28. As the movement to carbon-neutral buildings takes hold, makers of building materials are well aware of the need to improve the environmental footprint of their products. For its part, the steel industry has exceeded Kyoto accords for energy-efficiency improvement by more than 240 percent and made sizeable reductions in GHG emissions. According to the American Iron and Steel Institute, the industry has reduced its energy consumption by 33 percent since 1990.1 Coal figures heavily in energy consumption, but as steel scrap is increasingly used to make new steel, natural resources are being conserved and energy consumption reduced, with manufacturers reducing annual energy consumption by an amount that would power 18 million households for one year. While significant amounts of energy are required to convert iron ore and scrap to steel, the US EPA reports that the sector's energy use per ton of steel shipped improved over the last decade, with corresponding reductions in actual energy used. At the same time, the EPA states, "Release of CO2 is inherent to the chemical reactions through which iron ore is chemically reduced to make iron, and from the carbon content of iron when reduced to make steel. These emissions cannot be reduced except by changing the process by which iron and steel are made or by capturing and storing the CO2 after it is created. Research into new methods of steelmaking, is also targeting low-carbon processes." The steel industry has also established the carbon dioxide Breakthrough Program to fund the development of new steelmaking technologies. Source: 1 and-steel-institute-wins-energy-efficiency-award/- wins-energy-efficiency-award/ Photo: dreamstime (stock) Impact Mitigation: Steel  Increased recycling  Energy consumption reduced by 33% since 1990  Kyoto energy efficiency standards exceeded by more than 240%; GHG emission reductions  Program to develop low-carbon technologies Photo: dreamstime
  29. 29. Impact Mitigation: Concrete Mining, particularly open pit mining, is harsh on the environment. According to the Portland Cement Association, the cement industry is minimizing the disruption with "new technologies and a concerted effort to work closely with the communities in which quarries reside." Careful practices during operations minimize the impact, as does restoration of the sites to beneficial use. Sand, gravel, and crushed stone are typically mined in close proximity to their use, which gives quarry operators a strong incentive to be environmentally responsible and to maintain good relationships with the host community. Often, quarries are reclaimed for development, agriculture, or recreational uses. The Association says that, since 1972, the cement industry has reduced the energy it takes to make a ton of cement by over 37 percent, along with associated combustion emissions. In 1990, U.S. cement manufacturers set performance improvement goals—among them, a means for continuous improvement through Environmental Management Systems that track, report and improve environmental performance. Specific goals per unit of production were set for 2020 and include reducing carbon dioxide by 10 percent, energy use by 20 percent, and cement kiln dust by 60 percent. Recognising the need to reduce the CO2 intensity of cement production, the International Energy Agency has worked with the World Business Council for Sustainable Development (WBCSD) Cement Sustainability Initiative (CSI) to develop a technology roadmap for cement. This document outlines a possible transition path for the industry to make continued contributions towards a halving of global CO2 emissions by 2050. The roadmap estimates that the cement industry could reduce emissions b 18% from current levels by 2050. Sources: Portland Cement Association,; Concrete Joint Sustainability Initiative,; International Energy Agency, Technology Roadmap – Cement,,3861,en.html  Reduced emissions through improved manufacturing  Cement substitutes  Kiln fuel alternatives  Industrial heat recovery and carbon capture systems  Reuse of waste materials- blocks, recycled aggregate, etc.  On-board truck wash systems Photo: dreamstime
  30. 30. Maximizing resource use: the term “waste” is largely obsolete in the context of forest product manufacturing. The term 'waste' is largely obsolete in the context of today’s North American forest products industry. Logs brought to U.S. and Canadian sawmills and other wood product manufacturing centers are converted almost totally to useful products, leaving little to no waste. This is attributable to state-of-the-art sawmilling that maximizes the quality and quantity of boards that can be cut from a tree, combined with further processing fiber that is unsuitable for lumber production into composite products such as OSB or fiber boards and paper. It is also common for companies to have cogeneration facilities, also known as combined heat and power, which convert sawdust, bark and other residual fiber to electrical and thermal energy. In a carbon-focused world, this integration is especially important. Source: Utilization of Harvested Wood by the North American Forest Products Industry, Dovetail Partners Inc. Photos: Impact Mitigation: Wood  Maximizing resource use: the term “waste” is largely obsolete in the context of forest product manufacturing. Photos:
  32. 32. Minneapolis Energy-Efficient Home % Fossil Fuel Use by Life Cycle Stage Compared to manufacturing, which requires the greatest amount of energy in the construction process, transportation of building materials represents only a fraction of total fossil fuel consumption. For a typical wood-frame house in Minnesota, construction transportation constitutes only 3.6 percent of total fossil fuel consumption. That said, the impacts will be greater or less depending on the distance, mode of transportation, and material being transported. Source: This data was calculated by FPInnovations using the Athena Impact Estimator for Buildings, 2011 Transportation Effects  Represent a fraction of fossil fuel consumption in the construction process.  Impacts vary based on: - Distance - Mode of transport - Material transported Source: Athena Impact Estimator for Buildings, version 4.1.13
  33. 33. Transportation Impacts While distance may seem like the most significant element for determining transportation effects, a product travelling a long distance in a highly efficient mode will actually have a smaller environmental footprint than a product with fewer miles to travel in an inefficient manner. Road transport is by far the most carbon-intensive option, and is about six times more energy-intensive than rail transport and 15 times more energy-intensive than sea transport. Source: Brentwood Consulting, based on Leadership in Energy and Environmental Design values for energy use  Environmental impacts are a function of method as well as distance.  Values for energy use in the US LCI Database are: - Truck(2,127KJ/tonne-km) - Rail(373KJ/tonne-km) - Ship (138 KJ/tonne-km) Photo:
  34. 34. Transportation Effects  Wood – Light compared to other materials; transported by road from the forest to a mill and usually further by rail and ship  Concrete – Heavy; usually produced locally and transported short distances by truck  Steel – Heaviest; most iron ore is transported first by rail then ship Photo: dreamstime
  35. 35. Total Embodied Energy Embodied environmental impacts of various exterior wall assemblies When viewed overall, the embodied energy in wood products is significantly lower than the embodied energy in concrete or steel—either virgin or recycled. But there are other considerations when evaluating the choice of building materials ... Source: Data compiled by the Canadian Wood Council using the ATHENA EcoCalculator with a data set for Vancouver, British Columbia Source: Data compiled by the Canadian Wood Council using the ATHENA EcoCalculator with a data set for Vancouver, British Columbia
  37. 37. Is it Renewable? Concrete – NO Steel – NO Wood – YES ... such as renewability. A natural resource is renewable if it can be naturally replaced at the rate at which it is consumed. When the sand and gravel in concrete are mined from an area, they will not be replenished naturally in a reasonable time. Likewise, iron ore, the primary ingredient in steel, will not be replaced in a timely manner. Of the three building materials, wood is the only renewable resource. Is it Renewable? Concrete – NO Steel – NO Wood – YES Photos:
  38. 38. Is it Recyclable? Steel – YES Wood – YES Concrete / Cement – YES Recyclability, which also factors into environmental decision making, is another consideration. All three materials are recyclable. In the U.S., more than 80 million tons of steel are recycled each year and the overall recycling rate for 2011 was 92 percent. When one ton of steel is recycled, 2,500 pounds of iron ore, 1,400 pounds of coal and 120 pounds of limestone are conserved. However, there are still two considerations. First, the worldwide demand for steel outstrips the supply from demolished or scrap steel. Second, even though recycled steel requires about half the energy to produce as virgin steel, it is still considerably more than wood. Steel can also be reused. The industry says that steel frames with bolted connections can be easily dismantled. Entire structures are demountable and can be reconstructed in a different location in a matter of days. Concrete, too, can be recycled … and this is becoming an accepted way of disposing concrete structures that were once routinely shipped to landfills. Typically, concrete is collected and put through a crushing machine, often along with asphalt, bricks, and rocks. In reinforced concrete, the rebar is removed with magnets, and the remaining concrete chunks are sorted by size. Smaller pieces of concrete can be used for gravel for new construction projects, in shoreline protection, or as a road base. Recycled or reclaimed wood has the added cachet of architectural quality and character. Older beams and timbers are dense with a high ring count, and are praised by builders for their low moisture content. This makes them extremely stable, particularly in exterior situations. Antique wood has a striking patina that comes from oxidation that occurs on its surface. The color of old wood used in interior applications is generally mellower than the original, and history may also shine through, with the scuffs and scrapes of warehouse flooring still visible after sanding. Seasoned old growth lumber from demolition of historic structures has found new life as beams, exposed trusses, millwork, flooring, and furniture. Still, recycling timber is time-consuming and labor intensive—demolition must be careful to preserve as much of the timber as possible, wall studs must be trimmed off, nails pulled out and the lumber refinished. Recycled wood may not always fit in a new project, either from a size or a building code perspective, and there is not a well-established supply in many areas. Photo Source (in order): dreamstime, dreamstime, iStock
  40. 40. Sustainable Forest Certification  Verifies that a forest meets the requirements of the certification standard While all three materials can be recycled, wood is the only material that has third-party certification programs in place to confirm that products have come from a sustainably managed resource. While life cycle assessment evaluates the environmental aspects of products or materials, forest certification verifies the sustainability of forest management. More than 50 independent forest certification programs exist worldwide, reflecting the diversity of forest types, ecosystems, and ownership.  Two international umbrella organizations – FSC and PEFC The two largest umbrella certification programs are the Forest Stewardship Council (FSC) and the Programme for the Endorsement of Forest Certification schemes (PEFC). PEFC endorses the Sustainable Forestry Initiative (SFI), the Canadian Standards Association (CSA), and the American Tree Farm System (ATFS). All of these standards are used in North America and recognized internationally.  More than 50 certification standards worldwide
  41. 41. Leadership in Forest Certification Certified Forest Area in Canada & US 100 250 North America is internationally recognized for its supply of quality wood products from well-managed forests. As of August 2012, more than 500 million acres of forest in Canada and the U.S. were certified under one of the four internationally recognized programs used in North America: the Sustainable Forestry Initiative (SFI), Canadian Standards Association’s Sustainable Forest Management Standard (CSA), Forest Stewardship Council (FSC), and American Tree Farm System. Sources:,,,,, 80 60 40 200 150 100 50 millions of hectares millions of acres SFI FSC CSA ATFS 248 100 174 71 99 40 24 10 millions of acres millions of hectares
  42. 42. Leadership in Forest Certification This represents more than half of the world’s certified forests. Leadership in Forest Certification Sources:,,,, www.certificationcanada. org,  50 years of forest growth that exceeds harvest  More certified forests than anywhere else in the world As of August 2013 Sources:,,,,,
  43. 43. Responsible Procurement: Tracking Certified wood is the only product that can carry the added value of chain-of-custody certification—which confirms that it came from sustainably managed, certified  forests. Similar to tracking packages, chain-of-custody  third-party tracks forest products through all phases of ownership, processing and transportation, from the forest of origin to the end consumer. The chain-of-custody system is verified through an independent third-party audit. The result is that buyers know their building materials are coming from forests managed in accordance with strict sustainable forest management certification standards—and not from controversial sources such as illegal logging. The concrete and steel industries have no third-party sustainability certification or chain-of-custody certification. However, progress is being made in responsible procurement. In particular, some steel companies are reportedly encouraging suppliers to adopt responsible practices and/or management systems certified to ISO standards. In certain cases, companies dedicate online resources to screening potential suppliers and to promoting and monitoring the performance of existing vendors. Steel is often imported from developing countries and the absence of a third-party certification program makes it impossible to accurately assess the environmental and social impacts of steel products.   Photos: Chain of Custody certificate Sources: Photos: Manufacturing Timber importer Chain of Custody certificate Chain of Custody certificate Chain of Custody certificate Certified Forest Forest Management certificate Certified Logs Chain of Custody certificate Manufacturing Chain of Custody certificate Timber importer Sawmill Chain of Custody certificate Chain of Custody certificate
  44. 44. Environmental product declarations (EPDs) are the next wave in the world of environmental labeling. An EPD is designed to provide accurate, accessible and comparable information about the environmental impacts associated with goods or services. Much like nutritional food labels on products, EPDs are about making sure the data is transparent and leaving judgment up to the audience. Based on LCA data, EPDs are standardized (ISO 14025) and applicable worldwide for all interested companies and organizations. EPDs are voluntarily developed and include information about the environmental impacts of a product or service, such as raw material acquisition, energy use and efficiency, emissions to air, soil and water, and waste. They also include product and company information. The wood industry is taking a leadership role by adopting EPDs in advance of regulatory requirements. This will help to advance the sustainability cause in the building construction sector and demonstrate its strong environmental values. Examples of EPDs can be found at: American Wood Council, Canadian Wood Council, sustainability/life-cycle FPInnovations, Environmental Product Declaration  LCA-based tool for communicating the environmental performance of a product or system  Internationally defined in ISO 14025/TR  Applicable worldwide Photo:
  45. 45. In Summary: Materials Matter In reducing the environmental footprint of tomorrow’s structures, wood is a sustainable building choice. LCA studies repeatedly show that it outperforms steel and concrete in terms of embodied energy, air and water pollution and global warming potential. It stores carbon. Certified wood that has a chain-of- custody provides documentation of responsible procurement. And the forest industry creates jobs and well being for millions of people worldwide. Photo: W.G. Clark Construction, Ankrom Moisan Architects  LCA makes it easier to incorporate environmental considerations.  LCA studies show that wood outperforms steel and concrete in terms of embodied energy, air and water pollution, and greenhouse gas emissions.  Other benefits of wood include carbon storage, renewability, third-party certification and chain of custody. W.G. Clark Construction, Ankrom Moisan Architects
  46. 46. THANK YOU! For more information on building with wood, visit, or email with any questions.