How Much Insulation Do You Need?

The U.S. Department of Energy (DOE) recommends insulation levels based on a variety of factors, including the cost of energy in various parts of the country. The map below divides the United States into six zones, and the table below lists different R-values for each zone -- the first two for attics (with electric resistance-type heating or other type heating plants); the second for walls; and the third for floors.

Your local building codes may call for less insulation than the DOE recommends. In most cases, using the DOE recommendations will pay off over the long run in lower heating and cooling bills.