Insulation Cost Guides
What it costs to insulate and air-seal your home to cut energy bills and improve year-round comfort.
4 guides · figures cross-checked against current data ( methodology) · compare every project in the cost index.
How Much Does Blown-In Insulation Cost?
Blown-in insulation costs $0.90 to $2.40 per square foot installed in 2026, or about $900–$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, or about $1,700–$2,500 for a typical attic. Compare batt, 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 installed in 2026, or about $1,500–$6,000 per project. Compare open-cell vs. closed-cell foam.
$1.50 – $5 / sq ftHow Much Does Crawl Space Encapsulation Cost?
Crawl space encapsulation costs $3,000 to $8,000 in 2026 (about $3–$7 per sq ft). See the full breakdown, what a dehumidifier and drainage add, and what's worth it.
$3,000 – $8,000