Roof insulation cost energy efficiency in your home by slowing heat flow and keeping it in during cold weather. It also helps reduce cooling costs in summer and heating expenses in winter.

The cost of insulation varies depending on the type and material you choose. Some options, such as spray foam or cellulose, offer better R-values, but come at a higher price tag. The best choice depends on your budget and energy efficiency goals, as well as your location.

Roof insulation can be installed during new construction or after the fact in older homes. In new construction, a pro can put a layer of rigid foam board on the sheathing but beneath the shingles and then add fiberglass or mineral wool batting inside the attic between rafters. This option runs $1 to $4 per square foot. Wall insulation, on the other hand, is installed by putting mineral wool or fiberglass batts between wall studs. This option typically costs about $3 to $4 per square foot.

Calculating Roof Insulation Cost: Factors to Consider for Your Budget

Fiberglass blown-in insulation has a low initial cost but provides a lower R-value than some other types. Blown-in cellulose has a higher R-value and comes at a slightly higher price tag, but is more sustainable.

Spray foam is a high-tech option that is easy to install. It is partially composed of polyurethane, a plastic that effectively seals cracks and can fill small spaces. Spray foam is more expensive than other varieties, but it offers the highest R-value for the cost.