When it comes to the production of green-house gases, most people believe the worst culprits are the cars and trucks clogging the nation's highways. They're wrong. Between construction and maintenance, buildings produce the greatest portion of the dangerous emissions contributing to global climate change—up to 48 percent, according to studies by the U.S. Environmental Protection Agency.

In a survey released in September by the American Institute of Architects (AIA), only 7 percent of respondents accurately identified residential and commercial buildings as the primary cause of emissions. According to the survey, which polled a nationally representative sample of 1,000 registered voters, 40 percent of the respondents believed that cars and trucks were the greatest producers of greenhouse gases, which include carbon dioxide, methane, nitrous oxide, and ozone. Nearly 20 percent felt that power plants were the worst offenders, while 15 percent named natural causes. Another 18 percent either didn't know what caused most emissions or thought they came from a source not listed in the survey.

“The media has focused on transportation as a cause of noxious emissions,” says Paul Mendelsohn, the AIA's vice president of government and community relations. “With a car, however, after five or 10 years you can trade it in for something more efficient. We're trying to instill the concept that you can either design an energy-efficient building in the beginning or there are some simple things you can do once a building is constructed to make it more energy-efficient.”

Despite their misconceptions about the link between buildings and global warming, American consumers ironically want more energy efficiency in their homes. The same AIA poll indicated that 91 percent of the respondents would be willing to pay an additional $5,000 for a more energy-efficient house. Along the same lines, the AIA's Home Design Trend Survey for the second quarter of 2007 reflected a growing desire among homeowners for green products, including geothermal heating and cooling systems, tankless water heaters, and flooring made from easily renewable materials, such as bamboo and cork.

The AIA, for its part, will continue to impress upon its members, Congress, and the general public that energy efficiency is achievable whether in new construction or in existing buildings. “One of the things I've learned about architects is that many of them chose this profession because they wanted to make the world a better place,” Mendelsohn says. “We've seen a lot of success when architects go beyond the typical built environment and think holistically.”