If a green building is plopped in the middle of nowhere, is it still green?
The growing "green buildings" movement has developed computer models that go beyond measuring a building's carbon footprint and attempt to quantify the amount of energy people consume to reach that building.
Take Exelon Corp.'s headquarters in downtown Chicago, with its energy-efficient lighting, heating, ventilation, and cooling systems that power down on command, and lights that shut off automatically when a room is unoccupied. If it could be airlifted to the Chicago suburb of Hoffman Estates, how green would it be?
A calculator developed recently by the Center for Neighborhood Technology shows that with Exelon in the downtown district, 55 percent of its employees take public transportation to work and a small percentage bike or walk. But in Hoffman Estates, where public transportation is scarce, 99 percent of those employees would drive to work, with only 10 percent carpooling.
The energy spent commuting to Hoffman Estates, measured in British thermal units, would double. And each employee would add 22.9 pounds of heat-trapping gases to the atmosphere a day getting to and from work, compared with 16.2 pounds to the downtown site. (Cars emit about 25 pounds of carbon dioxide for every gallon of gas.)
Transportation emissions account for 29 percent of total U.S. greenhouse gas emissions, according to the U.S. Environmental Protection Agency, and the newly quantifiable data could spur development in urban areas served by public transportation.
Overall, one out of five trips and one out of four miles are traveled in commutes, according to Census Transportation Planning Products.
Opponents of the new green order are companies that build in more remote areas because land is cheaper, said Martha VanGeem, head of Chicago-based CTLGroup's building science and sustainability practice.