According to the Washington Times, zero-energy homes that use energy-efficient features to generate as much energy as they consume are gaining popularity among builders and home buyers. Builder trade groups increasingly are adopting green-building guidelines and holding seminars on eco-friendly building practices, among other steps. The Environmental Protection Agency assigns its Energy Star label to homes that cut fossil fuel use by 50 percent, lower water consumption by 50 percent and recycle 90 percent of organic waste and 75 percent of construction waste. These dwellings must exceed the energy-efficiency requirements under the 2004 International Residential Code by 15 percent or more, and they must score at least 86 out of 100 points in the Home Energy Rating System. With features such as high-efficiency insulation, appliances, and heating and cooling systems, these abodes can lower annual utility bills by $200 to $400. Homeowners also can receive up to $500 in federal tax credits for installing energy-efficient windows, insulation and other such products.   EC