2026 cost data
Insulation Cost in Montana (2026)
Insulation in Montana costs close to the national average — ranked 25 of 51 for installed price. Montana sits in climate zone 6, so attics should hit R-60.
Insulation prices per square foot
Installed prices — material plus labor — adjusted for Montana labor rates.
| Job type | Installed cost / sq ft | 1,500 sq ft attic |
|---|---|---|
| Attic blown-in fiberglass (R-49) | $1.81 | $2,720 |
| Attic blown-in cellulose (R-49) | $1.67 | $2,499 |
| Attic fiberglass batts (R-38) | $1.57 | $2,352 |
| Wall batts, open framing (R-15) | $1.71 | $2,573 |
| Wall dense-pack retrofit (drill & fill) | $2.55 | $3,822 |
| Crawlspace floor or wall insulation | $2.06 | $3,087 |
| Basement rigid foam + framing | $3.04 | $4,557 |
| Open-cell spray foam (3.5") | $1.91 | $2,867 |
| Closed-cell spray foam (2") | $3.53 | $5,292 |
| Old insulation removal & disposal | $1.52 | $2,279 |
What whole jobs cost
| Typical project | Local price range |
|---|---|
| Attic top-up (1,500 sq ft) | $1,470 – $2,548 |
| Full attic removal + re-insulate | $3,136 – $5,292 |
| Whole-house wall retrofit (2,000 sq ft home) | $4,116 – $7,644 |
| Crawlspace encapsulation + insulation | $3,724 – $8,820 |
| Garage conversion insulation | $882 – $2,156 |
| Whole-home spray foam (new build) | $7,350 – $15,680 |
Climate zone 6 R-value targets
Department of Energy retrofit recommendations for this zone.
- Attic
- R-60
- Walls
- R-21
- Floors
- R-30
Price your own job
These tables are averages. Punch in your real measurements for a number you can compare against a bid.
Insulation cost FAQs for Montana
How much does attic insulation cost in Montana?
A 1,500 sq ft attic blown to R-49 runs about $2,312 to $3,263 installed in Montana, or roughly $1.81 per square foot. DIY with rented equipment cuts that by 45–60%.
Is insulation cheaper to DIY in Montana?
Yes. Labor is most of an insulation bid, so blowing your own attic or installing batts typically saves 45–60% of the installed price. Spray foam, dense-pack wall retrofits and removal jobs are worth hiring out.
What drives insulation prices in Montana?
Local labor rates, how far crews travel, attic access, whether old insulation has to be removed first, and the R-value your climate zone calls for. Material prices barely change between states — labor is the swing factor.
Are there rebates in Montana?
The federal 25C tax credit (30% of insulation and air-sealing materials, up to $1,200 a year) only covered improvements made through December 31, 2025. For work done now, most utilities offer their own attic and air-sealing rebates, and income-qualified households can get free weatherization. Always check with your utility before booking work.
Materials for an insulation job in Montana
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