Basement insulation 101

Insulation keeps your basement warm in the winter, cool in the summer and dry all year long. But because it’s underground, you can’t approach insulating this area the same way you would the rest of the house. Here’s what you should know.

Exterior or interior?
If you’re building a new home, insulating the exterior of the basement walls is preferable. Exterior insulation prevents heat loss, inhibits moisture infiltration and takes up less space inside the house.

On an existing home, however, insulating the foundation is impractical and very expensive. Insulating behind the drywall provides similar heat retention and moisture inhibition. However, it does take up more room, which may be a consideration for people with smaller basements.

Types
The most commonly used types of insulation in basements are foam board, fiberglass and spray foam. Fiberglass is inexpensive but can settle and doesn’t protect from moisture. Spray foam is the most expensive type but can be used almost anywhere and, if properly installed, is water and air proof. Foam board is the easiest to install.

An uninsulated basement can be overly cold in the winter, too hot in the summer and uncomfortably damp year-round. By insulating the space, you’ll lower your energy bills and make it a more comfortable part of your home.