These days a green building means more than just the color of the paint. Green building can also refer to environmentally friendly houses, factories, and offices. Buildings account for 65 percent of total U.S. electricity use. But green buildings can reduce energy and water use. Also, the buildings are often located near public transportation such as buses and subways, so that people can drive their cars less. That could be good for the environment, because cars use lots of natural resources such as gasoline, and give off pollution. Green buildings are often built on previously developed land, so that the buildings don't destroy forests or other wild habitats(栖息地). Marty Dettling is a project manager for a building that puts these ideas into action. The Solaire has been called the country's first green residential high-rise building. According to Dealing, 'We've reduced our energy consumption by one-third and our water by 50 percent. Not everyone is leaping to move into a green building, however. Some people think that features such as solar panels cost more money than more traditional energy sources. Despite this, Dettling hopes that green buildings will become common in the future. 'It's going to be big', she said. What does green building refer to nowadays?