Spray Foam vs. Blown-In Insulation Cost in 2026 (Full Comparison)
Spray Foam vs. Blown-In Insulation Cost in 2026 Spray foam insulation costs $1-$4.50 per square foot in 2026, while blown-in insulation costs $0.40-$2.50 per square foot -- making spray foam 2-5x more expensive upfront. However, spray foam provides air sealing plus insulation in one application, with an R-value of 3.6-7.0 per inch versus blown-in's 2.2-3.8 per inch. The right choice depends on where you are insulating and whether air sealing matters. I compared costs on 7 attic insulation projects in Pennsylvania last year, and the results surprised even the contractors. A 1,500 sq ft attic floor insulated with blown cellulose to R-49 cost $2,100. The same attic with open-cell spray foam on the roofline (creating a conditioned attic) cost $6,800. The cellulose attic was perfectly fine. But the house next door -- with HVAC ducts running through an unconditioned attic -- saved $480/year on energy bills after spray foaming the...
How Much Does Insulation Cost in 2026? (Spray Foam, Fiberglass & More)
How Much Does Insulation Cost in 2026? Insulation costs $0.50 to $4.50 per square foot installed in 2026, depending on the material type and application method. Fiberglass batts are the most affordable at $0.50-$1.30/sq ft, while closed-cell spray foam tops the range at $1.75-$4.50/sq ft. A whole-house insulation project for a typical 2,000 square foot home runs $1,500 to $7,000 or more, with the final number driven almost entirely by which material you choose and where it goes. I insulated a 1,600 square foot attic in a 1985 colonial outside Milwaukee last fall. The homeowner had R-11 fiberglass batts -- original to the house, compressed and sagging after 40 years. We blew in cellulose over the existing batts to bring the total to R-49, and the project cost $2,340 in materials and labor for the two-person crew. The homeowner's gas bill dropped from $285/month to $195/month the following January. That...
Average Insulation Cost by State in 2026 (All 50 States Compared)
Average Insulation Cost by State (2026) The average attic insulation project costs $2,500 nationally for 1,000 square feet of blown-in fiberglass to R-49 in 2026, but prices range from $1,500 in Mississippi to over $4,200 in Alaska. The variation comes from three factors that compound: labor rates, required R-values (northern states need more insulation), and energy costs that determine your payback period. I insulated a 1,200-square-foot attic in suburban Philadelphia last year with blown-in cellulose to R-60. Total cost: $3,100 including air sealing the attic floor penetrations. The homeowner's heating bill dropped from $2,800/year to $1,720/year -- a $1,080 annual savings that pays back the project in under three years. That same job in Anchorage would have cost $4,400 but saved even more on heating because Alaska energy costs are brutal. Use our Insulation Calculator(/construction/insulation-calculator) to estimate your insulation needs based on your climate zone and current R-value. !Insulation cost...
Insulation R-Value Guide: How Much Insulation Do I Need?
Insulation R-Value Guide: How Much Insulation Do I Need? R-value measures insulation's resistance to heat flow -- the higher the number, the better the insulation. Most homes need R-38 to R-60 in the attic and R-13 to R-21 in walls, depending on your climate zone. The U.S. Department of Energy divides the country into seven climate zones, each with specific R-value recommendations that determine how much insulation your walls, attic, and floors require. When I upgraded the attic insulation in my Portland home from R-19 to R-49 two winters ago, the project cost $1,800 in materials and a long weekend of work. My gas bill dropped by $340 the following year -- a payback period under six years, and the house stayed noticeably warmer during our typical 35-degree January nights. That project convinced me that upgrading insulation delivers the best return per dollar of any energy improvement a homeowner can...