Attic Insulation Cost Calculator
Attic insulation installation for a typical attic averages about $2,100, and most homeowners pay $1,500 to $3,500. This calculator prices attic insulation cost from $1.50 to $4 per sq ft. A 1,000 sq ft attic with blown cellulose, the usual blow in insulation, is about $2,000.
Estimate attic insulation cost
Rough guide based on US averages. Real quotes vary by site, finish and contractor.
Estimates are indicative only. For an accurate price, get free quotes from local contractors above.
Attic Insulation Price Breakdown
Typical job based on 1000 sq ft. Prices are supply-and-install midpoints — actual quotes will vary.
| Type | Cost per sq ft | Typical 1000 sq ft job |
|---|---|---|
| Blown fiberglass | $2 | $1,500 |
| Blown cellulose | $2 | $2,000 |
| Open-cell spray foam | $3 | $2,500 |
| Closed-cell spray foam | $4 | $4,000 |
What Affects Attic Insulation Cost?
- Insulation material: Blown fiberglass is $1.50 per sq ft. Blown cellulose is $2 per sq ft and is the usual blown-in attic. Open-cell spray foam is $2.50 per sq ft. Closed-cell spray foam is $4 per sq ft. Fiberglass batts in an open attic usually cost about the same as blown fiberglass and are not a separate choice here.
- Attic size: Enter the attic floor area. A typical attic is about 1,000 sq ft, close to the home's footprint. At the cellulose rate that is about $2,000. An 800 sq ft attic is about $1,600, and a 1,500 sq ft attic is about $3,000.
- Old insulation: Adding over dry insulation is included in the base rate. Removing wet, moldy, or pest-damaged fill adds $1.50 per sq ft. On a 1,000 sq ft attic that is an extra $1,500. Air sealing around pipes, lights, and wiring is often $250 to $1,500 and is not included.
- Minimum job pricing: Very small attics use an $800 minimum. If the square-foot math comes in lower, the estimate starts at $800. Displayed estimates are plus or minus 20 percent around the midpoint.
Attic Insulation Cost - Frequently Asked Questions
For 1,000 sq ft, blown fiberglass is about $1,500, blown cellulose is about $2,000, open-cell spray foam is about $2,500, and closed-cell spray foam is about $4,000. The national average project is about $2,100, so the cellulose price is the closest match. The displayed range is plus or minus 20 percent. Removing old fill adds $1,500 on this size attic.
Blown in attic insulation is $1.50 per sq ft for fiberglass and $2 per sq ft for cellulose. On 1,000 sq ft that is about $1,500 or $2,000. The displayed ranges are about $1,200 to $1,800 for fiberglass and about $1,600 to $2,400 for cellulose. Most homeowners pay $1,500 to $3,500 for the whole project.
Spray foam insulation cost is $2.50 per sq ft for open-cell foam and $4 per sq ft for closed-cell foam. On 1,000 sq ft that is about $2,500 or $4,000. Closed-cell is the premium attic and sits above what most homeowners spend. Those prices do not include removal of the old fill.
Yes. Attic insulation installation over dry fill uses the base rate. Removing wet, moldy, or pest-damaged insulation adds $1.50 per sq ft. On 1,000 sq ft of cellulose, the job moves from about $2,000 to about $3,500. Air sealing is separate and is often $250 to $1,500.
Yes. Cellulose insulation is $2 per sq ft, and blow in insulation with fiberglass is $1.50 per sq ft. On a 1,000 sq ft attic that is about $2,000 for cellulose and about $1,500 for fiberglass. Both sit in the usual blown-in range.
Yes. If the square-foot price is under $800, the estimate starts at the $800 minimum. A typical 1,000 sq ft attic is above that. A radiant barrier, sometimes added in a hot climate, is often $0.10 to $2 per sq ft and is not included.