INSULATION
Blown-In Insulation Cost: Per Square Foot in 2026
Estimate blown-in insulation cost per square foot — with the free insulation calculator.
Blown-in insulation is the fast, effective way to insulate an attic — loose fiberglass or cellulose sprayed in a day. Here's the real 2026 cost.
THE SHORT ANSWER
The short answer
Blown-in insulation runs $3.75–$7.77 per sq ft installed in 2026 (Homewyse); most projects run $1.75–$7.50. A typical attic project runs $986–$2,333. A 1,000 sq ft attic runs $1,750–$7,500. Cellulose is cheaper than fiberglass.
What it costs
Blown-in insulation runs $3.75–$7.77 per sq ft installed (Homewyse May 2026). Most projects run $1.75–$7.50 per sq ft. A typical project runs $986–$2,333. A 1,000 sq ft attic runs $1,750–$7,500. Cellulose runs less; fiberglass more.
- Per sq ft: $3.75–$7.77
- Typical project: $986–$2,333
- 1,000 sq ft attic: $1,750–$7,500
- Cellulose < fiberglass
Blown-in vs batts
Blown-in fills every gap and is faster to install over an existing attic — the retrofit standard. Batts (fiberglass rolls) are cheaper for new construction but leave gaps if not cut perfectly. Blown-in cellulose adds soundproofing and fire resistance. Both need an air seal first.
Try the insulation calculator
Enter the area and per-sq-ft rates to estimate the job.