One of the primary concerns in green building is finding ways to conserve resources such as energy and water. The Environmental Protection Agency, or EPA, recommends the use of Energy Star-approved appliances, which are designed to reduce energy. You can purchase energy-efficient stove tops, ovens, microwaves, refrigerators, dishwashers or washers and dryers. The EPA’s WaterSense program also helps to promote water-efficient toilets and faucets. You may also consider installing a gray water system, which recycles your household waste water for use in your toilets. Solar panel or solar thermal heating systems can also be installed to produce electricity or heat and reduce your dependence on the traditional power grid.