Insulation · 2026 Pricing Guide
Spray Foam vs Batts: Pricing and When to Use Each
Spray foam vs batts is a units problem, board feet against square feet. Here is how to put both on one quote.
Standing in the attic doing the math? Price a job from a photo in about 6 seconds.
Spray foam vs batts: two products, two units
Insulation contracting is an $11.6 billion business in the United States this year, spread across 28,498 firms. Spray foam vs batts gets decided one cavity at a time.
Batts price per square foot of cavity. A batt is cut to a stud bay and goes in as one piece.
Foam prices per board foot. One board foot is one square foot sprayed one inch deep, so 100 square feet of wall sprayed three inches deep is 300 board feet.
So a bag price and a set price never compare. Convert both to installed cost per square foot of the same assembly.
The R-value target sets the inches
ENERGY STAR publishes the retrofit targets, which trace to 2021 IECC Table R402.1.3. An uninsulated attic wants R30 in zone 1, R49 in zones 2 and 3, and R60 from zone 4 up. Basement and crawlspace walls want an R13 batt in zone 3 through zone 4B, and an R19 batt in zone 4C and colder, with no target listed for zones 1 and 2.
Now convert that into depth. ROCKWOOL publishes a 9.5 inch Comfortbatt at R38, about R-4.0 per inch. Huntsman rates its Heatlok HFO Pro closed cell at an aged 7.4 per inch. Same target, roughly half the inches.
Scope before you price. In a deep open attic inches are cheap and batts win. In a 5.5 inch cavity or a rim joist, inches are the constraint and foam may be the only fit.
What each one costs
These ranges are what shops tend to quote. Treat them as a sanity check on your price book, not a sourced dataset.
| Factor | Batts | Open cell foam | Closed cell foam |
|---|---|---|---|
| Pricing unit | Per sq ft of cavity | Per board foot | Per board foot |
| Installed cost, guidance | $0.50 to $1.50 per sq ft | $0.40 to $0.75 per board ft | $1.00 to $1.50 per board ft |
| R-value per inch | About 4.0 (Comfortbatt 9.5 inch R38) | 3.7 to 4.0 (FOAM-LOK open cell) | 7.4 (Heatlok HFO Pro) |
| Air sealing | None on its own | Seals the cavity it fills | Air barrier in one pass |
| Moisture | Vapor open, needs a retarder | Vapor open, absorbs and dries | Resists bulk water |
| Equipment | Knife, staple gun, protection | Rig, hoses, suit, respirator | Rig, hoses, suit, respirator |
| Crew | Entry level with training | Certified applicator | Certified applicator |
| Best fit | Flat framing, attic floors | Roof decks, sound walls | Rim joists, crawlspaces |
The same wall, three prices
Take 1,000 square feet of 2×6 wall, 5.5 inch cavity.
Stone wool fills that cavity for about R-22 at Comfortbatt’s rate. At $0.50 to $1.50 installed, the wall runs $500 to $1,500.
Open cell fills the same 5.5 inches. That is 5,500 board feet. Huntsman rates FOAM-LOK open cell at an aged 3.7 to 4.0 per inch, so that depth lands near R-20 to R-22. At $0.40 to $0.75, the wall runs $2,200 to $4,125.
Closed cell clears R-22 in three inches. That is 3,000 board feet. At $1.00 to $1.50, the wall runs $3,000 to $4,500.
Same wall, comparable R-value, three different numbers. The gap is the air seal and the rig.
Mark up in the unit you bought in. Costing foam in board feet and marking it up on a square foot number gives back margin you earned.
Not sure where a cavity lands? Turn a photo into an itemized estimate in about 6 seconds. Free to try.
Where each one wins
- Attic floor over flat framing. Batts. Deep open space, cheap inches, no air-sealing demand.
- Unvented roof deck. Open cell. It seals the deck and follows framing a batt gaps around.
- Rim joists and crawlspace walls. Closed cell. Air and vapor control at the leakiest point in the house.
- Cut-up wall cavities. Foam. Every batt you trim and friction fit is labor nobody quoted.
Most whole house jobs end up mixed, and mixed is usually the cheapest spec.
Quote both before you leave
The strongest insulation bid puts a batt option and a foam option on one page. SimplyWise Cost Estimator turns a photo into an itemized estimate in about 6 seconds, with material quantities. Real-time material pricing sits behind the line items. On iPhone Pro models it scans a space with LiDAR for measurements. You hand over a professional, branded quote the client signs to approve.
It carries a 4.8 rating on the App Store. Pricing is $29.99/mo or $239.99/yr, about $20/mo on annual, with a 7-day free trial. One subscription opens every app in the SimplyWise suite. For the full takeoff workflow, read our guide to how to estimate insulation jobs.
Send both options before the next bid lands
Get an itemized estimate in about 6 seconds, while you are still in the crawlspace. Free to try.
Keep reading
Sources
- ENERGY STAR, Recommended Home Insulation R-Values (retrofit targets by climate zone, from 2021 IECC Table R402.1.3; verified live 2026-08-08).
- Huntsman Building Solutions, Heatlok Closed-Cell Insulation (Heatlok HFO Pro, aged 7.4 at one inch; verified live 2026-08-08).
- Huntsman Building Solutions, FOAM-LOK 500 Open-Cell Insulation (aged 3.9 per inch, R-3.7 per inch at 4 inches or greater; verified live 2026-08-13).
- ROCKWOOL, Comfortbatt (9.5 inch R38 stone wool option; verified live 2026-08-08).
- IBISWorld, Insulation Contractors in the US ($11.6 billion in 2026 across 28,498 businesses; verified live 2026-08-08).
- SimplyWise, Pricing (pricing, trial, suite access; verified live 2026-08-08).
- SimplyWise Cost Estimator on the App Store (4.8 rating; verified live 2026-08-08).
Nobody loses money on the foam. They lose it converting board feet into a square foot price.SimplyWise Editorial
Spray foam vs batts pricing: common questions
How much more does spray foam cost than batts?
Several times more on the same wall. As guidance rather than a sourced dataset, batts run roughly $0.50 to $1.50 per square foot installed, open cell $0.40 to $0.75 per board foot, and closed cell $1.00 to $1.50 per board foot. On 1,000 square feet of 2×6 wall that is $500 to $1,500 in batts against $3,000 to $4,500 in closed cell. Check the ranges against your own price book.
Why is spray foam priced per board foot instead of per square foot?
Because foam depth changes with the target. One board foot is one square foot sprayed one inch deep, so a 100 square foot wall sprayed three inches deep is 300 board feet. Batts are pre-sized to a cavity, so they price per square foot.
How much does SimplyWise Cost Estimator cost?
Pricing is $29.99/mo or $239.99/yr, about $20/mo on annual, with a 7-day free trial. One subscription opens every app in the SimplyWise suite. The Cost Estimator turns a photo into an itemized estimate in about 6 seconds, with material quantities.
Hand over both options before you leave.
Snap a photo, get an itemized estimate in about 6 seconds, and let the customer pick. Free to try.