Cost by insulation type
Installed cost varies by material:
- Blown-in (cellulose or fiberglass): $1 to $2.50 per sq ft
- Fiberglass batts: $1 to $2 per sq ft
- Spray foam: $3 to $7 per sq ft (highest R-value)
Best value first
Attic insulation is usually the cheapest, fastest, and highest-return insulation project, since most heat is lost through the roof. Sealing air leaks first makes any insulation work better.