In certain climates, an uninsulated foundation may account for up to 50 percent of the heat lost from an otherwise tightly sealed, well – insulated house.1 Proper installation of foundation insulation material is necessary to avoid moisture condensation, material damage, and structural decay caused by the differences in temper­ature between the house interior and the adjacent earth. Poor design and installation also may aggravate radon infiltration and insect infestation. It is best to research common methods and local guidelines depending on the specific climate, soil type, and design conditions.

Although considerable savings in heating costs can be achieved by insulating a foundation, installation costs are often high, par­ticularly for retrofit projects. The materials used, the location of the application, and the extent and timing of the work all affect the overall cost. While savings are accrued through energy-use reductions, “energy savers” financing packages, and home improvement savings programs, simple payback is typically the most popular analysis method. The payback period can range from 6 months for a simple do-it-yourself installation to 20 years for more involved work.1