According to USA Today, a growing number of American cities and states are adopting energy-efficient building codes to offset rising energy costs. Almost three times as many counties and cities passed green-building policies in 2007 as they did in 2004, according to the U.S. Green Building Council (USGBC). This year, no less than eight states and 22 cities have embraced green building codes.

In San Francisco, a new law mandates all new construction to meet energy and water conservation standards. New building laws recently adopted in Maryland, Indiana, New Jersey, Oklahoma, and South Dakota, meanwhile, require all new large state buildings meet the council's Leadership in Energy and Environmental Design standards. The USGBC's Jason Hartke cites higher energy costs and mounting concerns over greenhouse gas emissions' influence on climate change as the reasons driving the trend.