The world's leading certification system for sustainable architecture is set to undergo its most sweeping changes in 2009. The proposed revisions encourage designs that would reduce a building's impact on global climate change.
Leadership in Energy and Environmental Design, commonly known as LEED, has become the standard for green building design since the U.S. Green Building Council (USGBC), a nongovernmental organization, crafted the rating system eight years ago. Architecture that voluntarily improves energy efficiency, water conservation, and indoor air quality has surged in popularity in the past two years, especially in Europe and major U.S. cities.
According to USGBC's August statistics, more than 2,400 commercial and residential buildings worldwide are LEED certified, and nearly 14,000 are under way. The green building movement has the potential to significantly reduce global greenhouse gas emissions. In the United States, about 40 percent of all energy is used to heat, light, and cool residential and commercial buildings, according to the U.S. Department of Energy's Energy Information Administration.
Minimum LEED certification, however, does not necessarily guarantee environmental improvements. Developers who purchase environmentally related products off a LEED-supplied checklist may produce a LEED-certified building, but the building's future impact on energy and resource use is unknown. The proposed revisions are the beginning of a transition toward buildings that earn their green marks based on performance rather than eco-marketing.
The current LEED system allocates a maximum of 69 points for various environmental quality improvements. A building that receives 26 points is certified, and more points are necessary to receive the higher rankings of silver, gold, and platinum. While costly improvements such as solar panels are likely to boost a building's rankings, all categories are given equal weight, making some improvements less effective than others.
"LEED has been frequently criticized for not having a solid rationale for allocating credits," said Jerry Yudelson, a Tucson-based architect who teaches LEED-certification workshops. "The classic example is you get one point for putting in bicycle lockers and showers and one point for saving 7 percent of energy. Are those equivalent benefits?"
The new model emphasizes designs that the USGBC considers most beneficial for today's global environment. Improvements that reduce greenhouse gas emissions and burn fewer fossil fuels account for 34 of the 100 points. While a building requires only 40 points to receive certification, factors including access to transportation and energy efficiency can no longer be avoided, said Scot Horst, chair of the LEED steering committee. "We are saying climate change is the most important thing, so we put the most points to credits that deal with climate change," said Horst, president of the architecture consultancy 7Group. "If you want to get certified, you have to focus on those areas."
The new criteria place greater focus on the environmental impact of a building's entire life cycle. Contributions to eutrophication - the creation of oxygen-free dead zones in polluted water bodies - and "ecotoxicity" are now emphasized. Eventually, the USGBC envisions a system that assesses lifecycle impacts by measuring a building's pollutants, rather than being based solely on the attributes of building materials.
The 2009 LEED standards also plan to include more mandatory designs - most notably water efficiency. Building requirements, however, are not the same in all climates, and the stricter rules may further complicate efforts to streamline the process. Green developers in arid regions, for instance, struggle to balance air ventilation with energy conservation: if more hot air enters a building, more air conditioning is demanded.
To compensate for regional differences, the proposed standards grant local chapters "bonus points" that can be allocated toward design issues that would aid certification in that area. "This is the best way possible to give responsibility to chapters - they're the ones who know the local issues - without jeopardizing the consistency of LEED overall," Horst said.
But several architects still consider the system lacking. "There is a tension between having a national system... and yet still allowing a lot of regional differences," said Yudelson, who chairs the USGBC's annual conference committee. "[A solution] is for LEED 2012... We're not ready to make that big of a leap."
Regardless of the policy changes, some critics say a system like LEED does not do enough to improve the world's environmental woes. Architect Jonathan Ochshorn, an associate professor at Cornell University, said LEED-certified buildings are anecdotal examples of improvements that ultimately serve a corporation's profit, not the environment. "LEED in general is a way for institutions and corporations to collect points from a public relations standpoint," Ochshorn said. "The world isn't getting any better because of LEED."
The number of green buildings constructed remains relatively small - about 2 percent, according to a 2006 Green Building SmartMarket Report - due to higher building costs and the often stressful complexity of the certification system. To simplify the process, independent certifiers [PDF] have been hired to handle the growing number of certification requests. The costs are also beginning to fall as energy prices climb and green designs become mainstream.
"The changes in LEED are definite improvements, I think everyone is behind them, but we also need to improve the system," Yudelson said. "We need results, not just a certification on a building."
Ben Block is a staff writer with the Worldwatch Institute.