Most homeowners pay $1,500–$3,000 to insulate an attic, or about $1–$4 per sq. ft. installed, with national averages between $1,800 and $2,500. Spray foam on the roof deck can run up to $9,000, while topping up an existing layer with blown-in fiberglass can cost under $1,000 (Angi, HomeGuide and Forbes Home data, as of October 2026).
Updated October 8, 2026. Source: Angi + 3 more. National US estimates.
The attic is usually the cheapest place to cut heating and cooling losses. If you can see the tops of your ceiling joists, the insulation is thinner than the 10–14 inches ENERGY STAR suggests for most attics, and rooms below may feel hot in summer and cold in winter.
This guide covers costs per square foot by insulation type and attic size, a line-item breakdown for a typical blown-in job, and what removal, air sealing and access add. If the old insulation is wet, moldy or full of rodent droppings, read our attic insulation removal cost guide first.
Average cost
Installed prices for common attic insulation projects, national averages as of October 2026:
| Scenario | Typical range | Notes |
|---|---|---|
| Top-up with blown-in fiberglass or cellulose (500–1,000 sq. ft.) | $500–$2,000 | Added over existing insulation; one day or less |
| Typical attic, blown-in to R-38–R-49 with air sealing | $1,500–$3,000 | Most common project; averages $1,800–$2,500 |
| Remove old insulation and reinsulate | $2–$6 per sq. ft. | About $3,200–$10,800 for a 1,600–1,800 sq. ft. attic |
| Spray foam on the attic floor or roof deck | $1,100–$9,000 | Highest R-value per inch; also air seals |
Attic insulation cost by type
Installed prices; totals assume a 1,100–1,500 sq. ft. attic floor.
| Insulation type | Cost per sq. ft. installed | Typical total |
|---|---|---|
| Blown-in (fiberglass or cellulose) | $0.90–$2.40 | $900–$3,600 |
| Loose-fill | $1.00–$2.50 | $1,100–$3,800 |
| Batts and rolls | $0.80–$2.60 | $1,100–$3,900 |
| Reflective / radiant barrier | $0.50–$2.20 | $550–$3,300 |
| Spray foam | $1.00–$4.50 | $1,100–$9,000 |
| Structural insulated panels | $4.00–$12.00 | $4,400–$12,000+ |
Attic insulation cost by attic size
Installed cost at about $1–$4 per sq. ft.; spray foam and cold-climate depths push prices toward the top of each range.
| Attic floor area | Installed cost |
|---|---|
| 500 sq. ft. | $500–$2,000 |
| 700 sq. ft. | $700–$2,800 |
| 1,000 sq. ft. | $1,000–$4,000 |
| 1,500 sq. ft. | $1,500–$6,000 |
| 2,000 sq. ft. | $2,000–$8,000 |
Cost breakdown: materials, labor, permits and extras
Line-item estimate for blowing fiberglass or cellulose over existing insulation to reach R-38–R-49 in a 1,000 sq. ft. attic, with basic air sealing. Ranges are national, as of October 8, 2026.
| Cost item | Typical range | What it covers |
|---|---|---|
| Insulation (materials) | $400–$1,300 | Blown fiberglass or cellulose for roughly 10–14 inches of depth |
| Labor | $500–$1,300 | Installer crew and blowing machine, about $0.50–$1.30 per sq. ft. |
| Air sealing | $350–$750 | Sealing top plates, wiring holes, plumbing stacks and the hatch |
| Baffles, hatch and prep | $50–$200 | Soffit vent baffles at $2–$3 each, hatch insulation, light cleanup |
| Contingency (about 10%) | $100–$300 | Extra depth, hard-to-reach eaves, small repairs |
| Estimated total | $1,400–$3,850 | Before any discounts or rebates |
Labor and materials are roughly equal on a blown-in job; air sealing is a small extra that makes the new insulation work much better.
What affects the price
- Insulation type (fiberglass batts, blown-in, spray foam). Blown-in fiberglass or cellulose is the cheapest at about $0.90–$2.40 per sq. ft. installed; batts run $0.80–$2.60, and spray foam $1.00–$4.50 or more because it also air seals.
- R-value targeted. The Department of Energy recommends R-30 to R-60 depending on climate, and ENERGY STAR suggests R-38 (10–14 inches) for most attics. Colder regions need R-49 to R-60, which means more material and higher cost.
- Attic area. Price scales with the attic floor area: roughly $500–$2,000 for 500 sq. ft. and $2,000–$8,000 for 2,000 sq. ft. Some companies set a minimum project charge of $1,500–$2,000.
- Removal of old insulation. Removing old, compressed or contaminated insulation adds about $1–$2 per sq. ft., roughly $900 on average, so a full removal and reinsulation runs $2–$6 per sq. ft.
- Air sealing. Sealing air leaks before insulating costs about $250–$750 for a typical attic and up to $3,000 for leaky older homes, but it keeps warm, moist air from bypassing the new insulation.
- Access. Tight attics with low roof pitch, a small scuttle hatch or lots of ductwork take longer to work in. Labor runs about $70 per hour, and an average attic takes 6–8 hours.
Ways to save
- Add new insulation on top of the old layer when it is dry, clean and not compressed; removal can double the price.
- Choose blown-in fiberglass or cellulose instead of spray foam on the attic floor unless you are converting the attic to conditioned space.
- Ask your electric or gas utility and state energy office about insulation and air-sealing rebates, which often require a pre-approved contractor. The federal 25C credit ended for insulation installed after December 31, 2025.
- Book a home energy audit first; many utilities offer them free or discounted, and they show where air sealing gives the best payback.
- Get at least three quotes that state the material, target R-value and installed depth, not just a price per bag.
- For simple top-ups, DIY is realistic: adding about 5 inches of loose-fill over 1,000 sq. ft. costs roughly $200–$650 yourself.
Related questions people ask
How much does attic insulation cost on average?
The average cost of attic insulation is about $1,800–$2,500. Angi reports most homeowners pay $1,700–$2,500, while HomeGuide puts the typical range at $1,000–$2,700 and Forbes Home at $1,500–$3,500.
How much does spray foam attic insulation cost?
Spray foam costs about $1.00–$5.00 per sq. ft. installed. Spraying the attic floor runs about $1,100–$6,800, while spraying the underside of the roof deck to create a sealed attic costs $1,500–$9,000. Closed-cell foam costs more than open-cell but delivers roughly R-5 to R-7 per inch.
What is the attic insulation installation cost (labor)?
Labor quotes vary by source and material: HomeGuide puts installation labor at about $0.50–$1.30 per sq. ft., while Angi and Forbes Home cite $1.50–$3.50 per sq. ft. for more labor-intensive types. For a typical blown-in attic, labor is often $500–$1,300 and is usually rolled into one installed price.
How to get an accurate quote
Get at least three written quotes from insulation contractors. Share the same information with each:
- The attic floor area, how you access it (hatch, pull-down stairs) and the current insulation depth and type.
- Your target R-value and the material you prefer (blown fiberglass, cellulose, batts or spray foam).
- Any signs of moisture, mold, roof leaks or rodent activity, and whether you want the old insulation removed.
- Ask whether air sealing, baffles, hatch insulation and a depth certificate are included, and which utility rebates the contractor can process.
FAQ
How long does it take to insulate an attic?
An average attic takes a professional crew about 6–8 hours. Jobs that include removal of old insulation or extensive air sealing can take two days.
Is blown-in or batt insulation better for an attic?
Blown-in usually wins for existing attics because it fills gaps around joists, wiring and framing and costs about the same per sq. ft. Batts work well in open, unfinished attics with standard joist spacing.
Does attic insulation need to be replaced?
Not if it is dry, clean and at the right depth. Replace it after water damage, mold or rodent infestation. If you find mold, see our attic mold remediation cost guide before reinsulating.
More Insulation costs
Related cost guides
Sources
- Angi — How Much Does Attic Insulation Cost? (updated Jul 9, 2026). Checked October 8, 2026.
- HomeGuide — How Much Does Attic Insulation Cost? (Jan 13, 2026). Checked October 8, 2026.
- Forbes Home — How Much Does Attic Insulation Cost? (updated Feb 10, 2025). Checked October 8, 2026.
- HomeGuide — How Much Does Attic Insulation Removal Cost? (Nov 5, 2025). Checked October 8, 2026.
Prices are estimates and vary by location and provider. See our methodology and editorial policy. Browse all exterior cost guides.