Home Insulation Cost Calculator

Compare insulation costs by type and location. Get per-square-foot pricing for fiberglass, blown-in, spray foam, and rigid board.

✓ All insulation types compared

✓ R-value recommendations

✓ DIY vs. pro cost breakdown

Additional components

Estimated Cost

$5,000

Range: $4,250 \u2013 $6,000 \u2022 $5/sq ft

Cost breakdown

Vapor barrier$1,000
Insulation$1,500
Dehumidifier$1,200
Interior drainage$1,000
Vent sealing$300

Insulation Cost by Type

Insulation costs depend on the material type, R-value needed, and area to insulate. Here are current installed prices per square foot:

Fiberglass Batts: $0.50–$1.50/sqft — R-3.2 per inch, DIY-friendly

Blown-In Cellulose: $1.00–$2.00/sqft — R-3.5 per inch, good for attics

Open-Cell Spray Foam: $1.50–$3.00/sqft — R-3.7 per inch, air sealing included

Closed-Cell Spray Foam: $3.00–$7.00/sqft — R-6.5 per inch, moisture barrier + structural

Rigid Foam Board: $1.50–$4.00/sqft — R-5 per inch, best for crawl spaces/basements

Where to Insulate (Priority Order)

  • 1. Attic: Biggest ROI — 30–40% of home heat loss occurs through the roof
  • 2. Exterior walls: 20–25% of heat loss, but harder to retrofit
  • 3. Crawl space / basement: 10–15% of heat loss, prevents moisture problems
  • 4. Rim joists / band boards: Often overlooked, easy to seal with spray foam

Example: 1,500 sqft Attic Insulation

Fiberglass batts (R-38): $1,200–$2,250

Blown-in cellulose (R-49): $1,500–$3,000

Open-cell spray foam (R-38): $2,250–$4,500

Closed-cell spray foam (R-38): $4,500–$10,500

❄️ Energy Savings

Proper insulation reduces heating and cooling costs 20–40%. The average U.S. homeowner saves $200–$600/year, meaning most insulation projects pay for themselves in 3–7 years.

Frequently Asked Questions

How much does home insulation cost?\u25BE
Fiberglass: $0.50–$1.50/sqft. Blown-in: $1–$2/sqft. Open-cell spray foam: $1.50–$3/sqft. Closed-cell: $3–$7/sqft.
What R-value do I need?\u25BE
Attics: R-38 to R-60. Walls: R-13 to R-21. Crawl spaces: R-25 to R-30. Check your DOE climate zone.
Is spray foam worth the extra cost?\u25BE
For crawl spaces and rim joists, yes — it provides both insulation and air/moisture sealing. For open attics, blown-in cellulose often provides better value.