September 10, 2007—An examination of the “transportation energy intensity” of buildings has found that getting people to and from buildings uses more energy than the buildings themselves consume. The lead article in the September 2007 issue of Environmental Building News shows that for an average office building in the United States, 30 percent more energy is expended by office workers commuting to and from the building than is consumed by the building itself for heating, cooling, lighting, and other energy uses.
For an office building built to modern energy codes (ASHRAE 90.1-2004), more than twice as much energy is used by commuters than by the building.
“This was a huge surprise,” says Environmental Building News (EBN) executive editor Alex Wilson, author of the article. “I knew that transportation energy requirements were significant, but I was amazed at the differences.” For the article, Wilson collected average US data for commute distance, vehicle fuel economy, the split among different commuting options, and the number of square feet of building per office worker to normalize transportation energy intensity in Btu/square foot per year.
He was then able to compare that transportation energy intensity to the average building energy use (also in Btu/ft2-yr) for average existing office buildings and energy code-compliant buildings.
The full article on transportation energy intensity and the accompanying editorial can be accessed online. These articles are part of BuildingGreen Suite, a leading online resource on green building. While this is a paid-access site (with members paying $199 per year) these articles are provided free as a sampling of content.
