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| ENVIRONMENT | ||
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Pelli's Platinum Visionaire | |
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Green Stimulus Multiplication | |
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Green or Greenwashed? | |
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Green or Greenwashed? By one estimate, it takes the equivalent of clearcutting one acre (0.4 hectares) of forest to build a single 1,700-square-foot (160-square-meter) wood-framed home. Wood is used in 90 percent of the homes built in the United States. Since most of that wood goes into the framing and will never even be visible again, it begs the question: is logging the best use of finite forest resources? Alternative Building Materials Perhaps the first alternative to tree harvesting should be better reuse of already harvested timber. In 1996, the U.S. Environmental Protection Agency (EPA) estimated that the equivalent of 250,000 single-family homes are disposed of each year. This represents an estimated 1 billion-plus board feet (2.4 million cubic meters) of available salvageable structural lumber, or about 3 percent of the annual U.S. softwood timber harvest. Simply reusing this lumber could save an amazing 4,250,000 trees on 150,000 acres (61,000 hectares) of timberland every year. Tim Hermach, founder of the Native Forest Council in Eugene, Oregon, and some other environmentalists say we should learn from other countries that use a variety of other materials in home construction. There has been tremendous growth of environmentally friendly approaches in recent years — from energy-, water-, and waste-efficient designs that dramatically depart from traditional techniques, to alternative framing materials such as steel, concrete, cob, adobe, straw bale, and bamboo, says Cassandra Adams, a California architect who co-edited the book Alternative Construction. Of course, each alternative also has its own potential disadvantages and limitations. Adobe, known for its thermal mass, does well in the U.S. Southwest, but is no good for climates like Seattle, where it's cold and damp much of the year. Straw bale is bulky, making it difficult to build into dense urban settings. Concrete and steel take huge amounts of energy to produce. But it's not always that straightforward. Adams suggests that concrete or steel might be the more ecological choice if either of those materials could be sourced near the construction site, therefore cutting down on the amount of greenhouse gases that would be emitted trucking in building materials. Challenge Your Assumptions Our decisions are only as good as our assumptions. ln a controversial article published in the Forest Voice, a publication of the Oregon-based Native Forest Council, Mike Roddy, a steel construction proponent, challenged the lumber industry's assertions that wood harvesting has a lower carbon footprint than steel. After presenting a wealth of data, Roddy claimed, "harvesting wood for housing produces over seven times the greenhouse gas emissions of steel." Newer alternatives are also beginning to take forms that make it easier for them to break into the mainstream. While straw bale remains a novelty item, manufacturers are now making strawboard that combines "green cred" with the practicality of a product you can purchase ready to use and without a steep learning curve, says Eric Corey Freed, principal of organicArchitect, a San Francisco-based architecture and consulting firm. Building Green Momentum While sustainable building represents a small fraction of the houses built every year, it's a fast-growing market. The value of green building construction starts in the United States increased five-fold between 2005 and 2008, and, despite the country's current economic troubles, could triple — to between $96 billion and $140 billion — by 2013, according to estimates published in McGraw-Hill Construction's Green Outlook 2009: Trends Driving Change report. The LEED certification system has been a beneficiary of the recent growth. As of March 3, 2009, 2,384 buildings had received LEED certification, 926 of them in 2008 alone. More than 18,000 other buildings have been registered with LEED, indicating likelihood of future certification, according to the USGBC. Since LEED for Homes was launched in early 2008, 1,600 homes have earned that certification, and another 9,600 have been registered. Nonetheless, these growing numbers remain tiny for an industry which recently was building at a rate of two million houses per year in the United States, and which is projected to build some 500,000 new houses even in this year of economic crisis. The USGBC includes industry groups among its membership organizations and LEED committees, garnering both praise for balance and criticism over potential conflicts of interest. LEED is also criticized for not going far enough, including for allowing green certification of vast McMansion houses. But of the several green building standards in operation around the country, LEED is generally considered among the toughest, particularly on issues of energy efficiency and sustainable wood sourcing. The success of LEED — bolstered by continued improvements to the standard — represents a real driving force for environmentally improved design and building. That level of effective change-driving performance is not found in every green certification today, and it seems almost every week there's another announcement trumpeting the latest green product initiative or "third-party verified" certification program. Even Good Housekeeping magazine is planning to capitalize on its century-old product-approval program by rolling out a Good Housekeeping Green Seal for building and home improvement products. Greenish Noise Freed, the San Francisco architect, wonders whether the NAHB certification programs will rise above the "noise" created by so many competing green claims. He's not so impressed by certifications, anyway. Freed says the best way to evaluate the sustainability of your materials choices is to find the answers to a few questions: Where did the materials you use come from? How were they made? How are you using them and how can they be recycled when you are no longer using them? But he admits it's not necessarily easy to find the answers to those questions. "We do this for a living and it's hard for us to find out," Freed says. "Companies often don't know themselves and don't want to know." The basic question remains: does the NAHB's industry-controlled certification program really further the vital mission of reducing the environmental footprint of design and construction? The NAHB's offerings won't be making inroads with people like Sandra Mallory, the program manager for the City of Seattle's green building program. She says she's satisfied with LEED and with Built Green, a local standard created by builders in Washington's King and Snohomish Counties. Mallory says "it's fine" that the NAHB has come up with its own green certification programs, but she doesn't expect to use them or even learn more about them. Editor's Note — For those who understand and believe in science, the knowledge is crystal-clear that after centuries of accelerating industrial impacts on natural ecosystems, we have drastically drawn down our planet's natural capital. It is even likely that various impacts of natural capital exhaustion are significant background factors in the current global economic crisis. Strategically speaking, we can't afford to waste our forests any longer. Perhaps, with more than 50% of US homebuilding companies projected to go out of business before the current economic crisis is over, instead of campaigning to undermine LEED, the NAHB could focus on more broadly beneficial ways to help its membership — and all their customers as well. Christine MacDonald is the author of Green, Inc.: An Environmental Insider Reveals How a Good Cause Has Gone Bad, Lyons Press, 2008. Discuss this article in the Architecture Forum...
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