Insulation cost per square foot by type
| Insulation type | Installed price | Good to know |
|---|---|---|
| Fiberglass batts and rolls | $0.80–$2.60 | Rolls between wall studs or attic joists; the cheapest option |
| Blown-in fiberglass or cellulose | $1–$2.80 | Loose fill blown over an attic floor or into closed walls |
| Open-cell spray foam | $1.50–$3.50 | Sprayed foam that expands and stays soft; blocks drafts |
| Closed-cell spray foam | $3–$5 | Denser foam that adds strength and resists moisture |
The guides disagree more than usual on insulation. For blown-in, Fixr starts at $0.50 per square foot and Angi runs up to $4, because Angi prices an attic job and Fixr includes simple, open-floor jobs. Only HomeGuide separates open-cell from closed-cell foam. Angi and Fixr give a single spray foam price that sits between the two (Angi $2-$5 per square foot and Fixr $3.15-$7.50 in existing homes), so a closed-cell quote can land above the range in the table.
What changes the price
- Type and thickness. Higher R-value means more material, which is why closed-cell foam and a deep layer of blown-in cost more.
- Where it goes. An open attic floor is the easiest. Finished walls, sloped ceilings and crawl spaces take more labor.
- Old insulation. If wet, moldy or compacted insulation has to come out first, removal is an extra per-square-foot charge.
- Air sealing. Sealing leaks before insulating is a separate job that often pays off.
- Minimum fee. Small jobs are often priced at the company's minimum rather than by the square foot.
- Where you live. The calculator adjusts the labor share for your state's insulation worker wages.
Extras to expect
| Item | Typical cost | When it applies |
|---|---|---|
| Removing old insulation | $1–$2 per sq ft | Damaged, wet or compacted insulation |
| Attic air sealing | $250–$3,000 | Drafty attics, before adding insulation |
Insulation also affects other jobs. Moisture in an attic can lead to mold, which is priced on the mold remediation cost page, and a roof replacement is a good time to add more insulation. See roof replacement cost.
Questions to ask before you hire
- What R-value does the quote deliver, and how thick is the layer?
- Is the price per square foot or a flat project price, and is there a minimum fee?
- Does it include air sealing, baffles and removing the old insulation?
- For spray foam, is it open-cell or closed-cell, and what is the warranty?
- Are there utility rebates or tax credits I should claim?
Methodology and sources
We price each type per square foot from three published guides, take the middle of their lows, midpoints and highs, and adjust the labor share for your state's wages. Spray foam is priced by HomeGuide alone. This Old House uses Angi's contractor estimates, so it is not counted twice. Read how we estimate costs.
- HomeGuide: insulation cost — batts, blown-in, removal, air sealing, minimum fees
- HomeGuide: spray foam insulation cost — open-cell and closed-cell prices
- Angi: attic insulation cost — price per square foot by material, removal, air sealing
- Fixr: home insulation cost — batts, blown-in and removal
- Forbes Home: attic insulation cost — used as an independent cross-check
- BLS OEWS May 2025, State (SOC 47-2131, Insulation Workers) — state labor index; DC, Hawaii and Rhode Island use neighboring states
What each source reports
Our estimate does not rely on any single page. This table lists each page we used and the figures it reports, so you can see where the ranges come from.
| Source | What it reports |
|---|---|
| HomeGuide |
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| Fixr |
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| Angi |
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| HomeGuide |
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Common questions about insulation costs
How much does insulation cost?
A typical job (1,000 sq ft, blown-in) comes to about $1,800 nationally, within a range of $1,000 to $2,800. Use the calculator above to adjust for your state, the options you choose and any extras.
How much does attic insulation cost?
Blown-in insulation, the usual choice for an attic, costs about $1–$2.80 per square foot installed. A 1,000 sq ft attic is $1,000–$2,800 and a 1,500 sq ft attic $1,500–$4,200. Fiberglass batts are $0.80–$2.60 per square foot.
How much does spray foam insulation cost?
Open-cell spray foam costs about $1.50–$3.50 per square foot installed and closed-cell about $3–$5. For 1,000 sq ft that is $1,500–$3,500 for open-cell and $3,000–$5,000 for closed-cell.
What is the difference in cost between open-cell and closed-cell spray foam?
Closed-cell costs roughly one and a half to two times as much per square foot, $3–$5 against $1.50–$3.50. Only one of the guides we read prices them separately, so ask installers for both.
What is the insulation cost per square foot?
Batts and rolls cost $0.80–$2.60, blown-in $1–$2.80, open-cell spray foam $1.50–$3.50 and closed-cell spray foam $3–$5, installed.
How much does it cost to insulate a whole house?
For 2,000 sq ft of walls or attic, blown-in costs $2,000–$5,600, batts $1,600–$5,200 and closed-cell foam $6,000–$10,000. Walls in existing homes are harder to reach than an attic floor, so they usually sit toward the high end.
How much does it cost to remove old insulation?
Removal costs about $1–$2 per square foot. For a 1,000 sq ft attic that adds roughly $1,000–$2,000.
Do I need air sealing before adding insulation?
Often, yes. Sealing gaps around pipes, wires and the attic hatch makes the new insulation work better. Attic air sealing costs about $250–$3,000.
Is there a minimum charge for an insulation job?
Many companies set a minimum project fee of $1,500 to $2,000 or more, according to one guide, so a very small attic may cost more per square foot than the table shows.
Where do these prices come from?
They come from 4 published cost pages from 3 publishers, last checked Oct 8, 2026. We report what those pages say and do not invent figures; the table above shows each source.
How does my state change the estimate?
The labor part of the price is scaled by the average wage for the relevant trade in your state, using Bureau of Labor Statistics data. Materials and equipment are not adjusted.
Why might a contractor's quote differ from this estimate?
A quote reflects your specific scope, access, local demand and what the contractor includes. Ask for line items rather than a single total so you can compare bids on the same basis.
All 4 sources behind these prices
Every figure in the calculator comes from one or more of these pages, with the number each one supports in the link text.