Blown-In Insulation Cost (Per Sq Ft, 2026)
Part of Interior & Finishes
Quick answer
Blown-in (loose-fill) attic insulation costs roughly $1.50–$3.50 per square foot installed, with a national average near $2 (as of June 2026). That's about $1,500–$3,500 for a typical 1,000 ft² attic blown to R-49. Material alone is $0.50–$1.50/ft²; pro labor adds $1–$2. Cellulose costs a little more than fiberglass but reaches the target R-value in less depth.
Blown-in insulation is priced per square foot of attic floor, and the cost splits three ways: the loose-fill material, the labor and blower, and any prep (air-sealing, baffles, removing old insulation). It's the cheapest way to hit a high attic R-value, well below spray foam.
Cost per square foot (open attic)
| Cost line | Per ft² | Notes |
|---|---|---|
| Material only (loose-fill) | $0.50–$1.50 | Bags at the store |
| Pro labor | $1.00–$2.00 | Crew, blower, setup, cleanup |
| Installed (open attic) | $1.50–$3.50 | National average ~$2 |
| DIY (material + rented blower) | $0.90–$1.80 | You supply the labor |
Cellulose vs. blown fiberglass
| Material | R per inch | Material / ft² | Notes |
|---|---|---|---|
| Blown fiberglass | ~2.5 | $0.50–$1.10 | Lightest; doesn't settle much |
| Blown cellulose | ~3.2–3.7 | $0.60–$1.80 | Less depth for same R; recycled |
Typical attic cost (blown to R-49)
| Attic floor | Installed cost |
|---|---|
| 500 ft² | $750–$1,750 |
| 1,000 ft² | $1,500–$3,500 |
| 1,500 ft² | $2,250–$5,250 |
| 2,000 ft² | $3,000–$7,000 |
Get the depth and the number of bags from the insulation calculator (attic area + target R-value), then multiply the area by a per-ft² figure above — or the bags by your store price. If you're topping up over existing insulation, only the added inches count. Many attic-insulation upgrades qualify for the federal 25C tax credit (30% of cost, up to $1,200/yr). Source: US national average installed-cost references. Last verified: June 2026.
FAQs
How much does it cost to blow insulation in a 1,000 sq ft attic?
About $1,500–$3,500 installed to blow it to R-49, with most homeowners near $1,900–$2,000. The low end is an easy top-off over existing insulation; the high end includes air-sealing and removing old material.
Is blown-in cheaper than spray foam?
Much cheaper. Blown-in runs about $1.50–$3.50 per square foot installed versus $3–$8 for spray foam. Blown-in wins for an open attic floor; spray foam is for air-sealing a roofline or rim joist.
Is cellulose or fiberglass better for blown-in?
Both work well in an attic. Cellulose has a higher R-value per inch (so less depth) and better air-flow resistance; fiberglass is lighter and settles less over time. Cellulose costs a little more per square foot.