Nowhere has the greening message had a bigger impact than in the building industry. Green or sustainable architecture is all the rage—as well it should be, because buildings use a lot of energy. The construction and operation of residential and commercial buildings consume as much as 40 percent of the energy used in the United States today.
The calculation of a building’s total environmental impact must factor in everything from annual energy consumption to how and where building materials are manufactured and the handling of storm water. This requires some sort of rating system, and there are currently more than 40 of them in use around the world. Most, like LEED (Leadership in Energy and Environmental Design), which has become the standard in the United States, award points based on a checklist—daylighting, water recycling, solar panels, bicycle racks, and so on.
Although it is estimated that fewer than 6,000 projects have been certified in the United States in the 10 years since LEED was established, the program has significantly raised public and professional awareness. Yet a checklist approach has drawbacks. It tends to focus attention on unusual features, such as green roofs. Growing grass on a roof is definitely photogenic, but it is not as energy- and cost-efficient as simply painting the roof white (see “The California Experiment,” page 66). And checklists—even weighted checklists—may produce misleading results. Both a suburban office campus and an urban high-rise office building, for example, can receive a high rating. As David Owen points out in his forthcoming Green Metropolis: Why Living Smaller, Living Closer, and Driving Less Are the Keys to Sustainability, in the office campus, people work in sprawling buildings and drive between them; in the high-rise, people work in a compact building, use elevators (which are inherently energy-efficient, since they are counterweighted), and walk to lunch.