Your Thermostat's Power

Your thermostat is the single most powerful energy tool in the house, because it controls the heating and cooling that dominate the energy bill. Setting it back about 7 to 10 degrees for roughly 8 hours a day — while you sleep or are out of the house — can cut heating and cooling costs by as much as 10 percent a year, with no real hit to comfort. As a rule of thumb, expect close to 1 percent of savings for each degree you set back over an 8-hour stretch, which is exactly what a simple programmable schedule does for you.

Insulation matters even more than the thermostat setting. A poorly insulated attic can leak up to 25 percent of your home's heat in winter. Sealing drafts around windows and doors costs almost nothing but delivers year-round returns.