As air-conditioning demand has increased significantly during the last decade, efficient energy use has become more important due to large electric power demands and limited reserves of fossil fuel. Electrical energy use fluctuates significantly during a 24-hour day due to variable demand from industrial, commercial, and residential activities. In hot and cold climates, the dominant part of the load fluctuation is caused by cooling and heating demands, respectively. If electric loads could be shifted from peak hours to off-peak hours, not only would building operation costs decrease but the need to run peaker plants, which typically use more fossil fuels than non-peaker plants, would also decrease. Thus, shifting electricity consumption from peak to off peak hours promotes economic and environmental savings. This paper uses simulation and experimental work to examine 12 precooling strategies in three residential buildings in the Phoenix, Arizona, climate. The selected buildings are considered to represent the majority of residential buildings in the area. Results of this project show that precooling can save up to 46% of peak energy demand in a home constructed with concrete or cementitious block and up to 35% in wood frame homes. Homeowners can save up to U.S. $244/year in block construction and up to U.S. $119/year in wood frame homes.