Increased LEED Credits for Use of Certified Wood
In early April, U.S. Green Building Council (USGBC) announced its expansion of the number of wood certification programs that it would recognize as qualifying for LEED credits. USGBC’s new pilot program, which applies to LEED 2009 and LEED v4 systems, provides an Alternative Compliance Path credit for projects that use wood verified to be from legal sources by any of the following organizations: Forest Stewardship Council (FSC), Sustainable Forestry Initiative (SFI), American Tree Farm System (ATFS), and the European-based Programme for the Endorsement of Forest Certification (PEFC). This is in addition to the existing credit for wood products certified by FSC as having been obtained from responsibly managed sources.
Although some LEED credits can be obtained based on the percentage of certified wood used on a project, the new program greatly increases the sources of wood for which credits can be received. In addition to providing certainty to contractors that the wood they use has been obtained from legal sources, the program will help reduce unregulated and environmentally harmful logging, which is a problem in the host of countries that lack the rigorous environmental enforcement mechanisms such as exist in the United States. The program also incentivizes the use of wood as a building material that is both sustainable and can sequester carbon for decades.
Public and Private Interest in Expanding Wood as a Structural Component in Major Projects
USGBC’s move comes as new technology has resulted in the development of structural wood building products, such as cross-laminated timbers, that perform at least as well as less sustainable materials. Cross-laminated timbers consists of three, five or seven layers of wood beams laid at right angles to one another and bound together with a specially designed adhesive. Use of this product in building construction carries several advantages. The resulting timbers can be cut to desired dimensions, yielding structural components that are lighter than concrete and steel yet just as strong and durable. Surprisingly, the adhesive used in producing cross-laminated timbers creates wood products that are highly fire resistant. Another advantage of building with light, cut-to-order structural wood is that the job can be completed more quickly, with less noise, waste, and labor costs than structures utilizing more traditional building materials. And, unlike cross-laminated timbers, most of the traditional building materials have a larger carbon footprint and do not carry comparable “green” certification.
For these reasons, the incorporation of structural wood materials into building construction is gaining momentum, particularly with the support of federal and state governments. For example, as part of the Fiscal Year 2016 Military Construction, Veterans Affairs, and Related Agencies Appropriations bill, the House Appropriations Committee inserted language encouraging the Department of Defense to collaborate with the U.S. Department of Agriculture and the U.S. Forest Service to jointly develop a plan on expanding the use of innovative renewable building materials, specifically including cross-laminated timbers. The Department of Defense has already awarded a contract for hotel construction to a firm that used exclusively cross-laminated timbers for the project’s structural components. There are also plans to construct a building made of cross-laminated timbers on the Oregon State University campus, which is funded in part by state bonds.
Moreover, in 2014, the U.S. Department of Agriculture, in partnership with the Softwood Lumber Board and the Binational Softwood Lumber Council, announced the U.S. Tall Wood Building Prize Competition. The competition was open to teams of architects, engineers, and developers, and was designed to showcase the architectural and commercial viability of advanced wood products like cross-laminated timbers in tall buildings. In 2015, the two winners each received grants of $1.5 million. The West Coast winner was a project called “Framework,” a 12-story building to be constructed primarily of cross-laminated timbers, which will house a blend of street-level retail, office, workforce housing and community space. On the East Coast, a 10-story condominium building, to be the largest wooden structure in the New York City, was named the winner.
Recently, five Senators introduced the bipartisan “Timber Innovation Act” (S. Bill 2892), which would authorize the Tall Wood Building Prize Competition annually for five years. The Act would also create federal grants designed to advance the research, development, and use of wood as a structural material in tall building construction, i.e., buildings over 85 feet high, or approximately seven or more stories tall. This Act has strong support from the forest products industry.
Not to be outdone, private projects around the country are also starting to get into the game. Examples include the use of cross-laminated timbers for two multi-story buildings on the West Coast, a large pavilion on the lakeshore in Chicago, as well as a building at the Oregon Zoo.
Internationally, London is developing the first wooden skyscraper, the nearly 1,000-foot high “Oakwood Tower,” and is already home to an apartment block, which is currently the tallest cross-laminated timber building. Other buildings incorporating cross-laminated timbers include the Trätoppen tower in Stockholm, the Arbora project in Montreal, a residential block in Melbourne, and an apartment building in Norway.
Although U.S. and Canadian building codes do not yet explicitly recognize cross-laminated timbers, this does not prohibit its use under code provisions allowing for “alternate methods” of construction. Additionally, in the 2015 IBC, recently approved changes will streamline the acceptance of cross-laminated timber buildings. The 2015 IBC recognizes cross-laminated timber products when they are manufactured according to the IBC standard. In addition, cross-laminated timber walls and floors may be permitted in all types of combustible construction, including Type IV buildings.
Additionally, the American Plywood Association (APA) has a published document, ANSI/APA PRG 320-2012, Standard for Performance Rated Cross-Laminated Timber,which serves as the U.S. standard for cross-laminated timbers and provides structural grading classifications, design values, and requirements and test methods for qualification and quality assurance. In 2015, the first lumber mill in the U.S. was certified to produce APA/ANSI compliant cross-laminated timber products. The Oregon mill is already under contract or in design conversations with over a dozen projects.
USGBC’s announcement of greater opportunities for LEED credits through the use of wood in building construction is the latest evidence of the increased viability of wood as a structural component in major building projects. This announcement, coupled with the already growing interest in and government support for the use of structural wood, such as cross-laminated timbers, is almost certain to continue as part of the search for environmentally friendly and structurally sound building materials.