Insulation Cost Guides
What it costs to insulate your home and seal air leaks, which can lower energy bills and keep rooms more comfortable.
4 guides. We check the prices against 2026 sources (see how we get our numbers). To compare every project, see the cost index.
How Much Does Blown-In Insulation Cost?
Blown-in insulation costs $0.90 to $2.40 per square foot in 2026, or $900 to $3,600 for an attic. Compare cellulose, fiberglass and mineral wool.
$0.90 – $2.40 / sq ftHow Much Does Attic Insulation Cost?
Attic insulation costs $1 to $4 per square foot installed in 2026. A typical attic costs $1,700 to $2,500. Compare batts, blown-in and spray foam.
$1 – $4 / sq ftHow Much Does Spray Foam Insulation Cost?
Spray foam insulation costs $1.50 to $5 per square foot in 2026, or $1,500 to $6,000 for most jobs. See when open-cell or closed-cell foam is worth it.
$1.50 – $5 / sq ftHow Much Does Crawl Space Encapsulation Cost?
Sealing a crawl space (encapsulation) costs $3,000 to $8,000 in 2026. Most people pay about $5,500. See what a dehumidifier adds and why to fix water first.
$3,000 – $8,000