Cost breakdown
| Item | Typical price |
|---|---|
| Open-cell (per sq ft) | $0.45 – $1.50 |
| Closed-cell (per sq ft) | $1.00 – $2.50 |
| Attic (average) | $1,500 – $4,000 |
| Whole-home new build | $4,000 – $8,000 |
| Per board foot | $0.50 – $1.50 |
Estimates only — your exact price depends on your home. Get local quotes for the real number.
What drives the price
- Open-cell vs closed-cell — the biggest driver.
- Area & thickness (R-value)
- Attic, walls, or crawl space
- New construction vs retrofit
- Accessibility
How to save on spray foam insulation
- Use open-cell for interior walls/attics and reserve pricier closed-cell for crawl spaces and where you need a moisture barrier.
- Check for utility rebates and the federal insulation tax credit.
- Insulate during a remodel when walls are already open to avoid extra labor.
- Get the R-value/thickness spelled out in the quote so you're comparing equal jobs.
How to get an accurate spray foam insulation quote (and avoid overpaying)
National averages tell you the ballpark; only a quote tells you your number. Here's how to get a fair one:
- Get at least 3 itemized quotes. For the same spray foam insulation, bids routinely vary 20–40%. Comparing line items (not just the total) is the fastest way to spot padding.
- Check license & insurance. Ask for the contractor's license number and proof of liability + workers' comp. Unlicensed/uninsured bids are cheaper for a reason.
- Beware the extremes. A bid far below the others usually means a missing scope item or a bait price; a high-pressure "today only" quote is a classic overpay trap.
- Get it in writing. The quote should list materials, labor, what's included (removal, permits, cleanup), the timeline, and the warranty.
- Confirm what's not included. Removal/disposal, permits, and code upgrades are the line items that turn a "cheap" bid into the expensive one.
Frequently asked questions
A typical project runs $1,500–$5,000, averaging ~$3,000. Closed-cell costs roughly double open-cell.
It air-seals as it insulates, often cutting energy bills 15–30% — the premium over fiberglass usually pays back in a few years.
Closed-cell has a higher R-value and adds a moisture/air barrier; open-cell is cheaper and fine for interior walls and attics.
Spray foam runs about $0.45–$1.50 per square foot for open-cell and $1.00–$2.50 for closed-cell. A typical attic or project totals $1,500–$5,000, averaging ~$3,000.
These are national averages — your actual spray foam insulation price depends on your home, your ZIP, and who you hire. Get up to 3 real quotes and stop guessing.
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Sources & methodology
Our price ranges are compiled and cross-checked against published cost studies, industry datasets, and current contractor pricing, then reviewed against the sources below. Cost guides are estimates, not quotes — local pricing varies by region, materials, and labor.