Though the southwestern Pennsylvania metropolitan area is only the 22nd largest in the United States in terms of population, the city employed energy-efficient construction well ahead of larger cities. In 2005, Pittsburgh claimed more LEED-certified square footage -- meaning it had met Leadership in Energy and Design standards for energy-saving designs and building techniques -- than anywhere else in the United States. As other cities have caught up, Pittsburgh now ranks seventh nationally in the number of buildings with such certification, according to the local Green Building Alliance.
Founded in 1993, the alliance says it is the first nonprofit organization in the nation to encourage green commercial building. "There was no government-driven agenda here," said Rebecca Flora, former director of the Green Building Alliance and now senior vice president of education and research at the national Green Building Council, a nonprofit organization that oversees the LEED program. "Pittsburgh's doing green in a weak market city with existing building stock, and it's done it without government programs."