Insulation Cost Guide: What to Expect in 2026

Cost by material (installed)

Blown fiberglass: $0.80-$2.50 per sq ft

Blown cellulose: $1.00-$2.75 per sq ft

Fiberglass batts: $0.65-$2.00 per sq ft

Open-cell spray foam: $1.00-$1.50 per board foot

Closed-cell spray foam: $1.75-$3.00 per board foot

Rigid foam board: $0.40-$2.00 per sq ft (DIY-friendly)

Mineral wool batts: $1.50-$3.50 per sq ft

Cost by project

Attic blow-in to R-49 (1,500 sq ft home): $1,500-$4,000

Whole-home air sealing: $350-$900

Crawl space encapsulation + insulation: $3,000-$10,000

Wall dense-pack cellulose retrofit (1 wall): $1,500-$4,500

Spray foam in 1,500 sq ft basement walls: $3,000-$7,500

Insulation removal (contaminated): $1,000-$3,500

What's usually included in a quote

Materials (labeled with R-value and product brand)

Labor and equipment (blower truck, hoses, PPE)

Site protection and cleanup

Disposal of any removed insulation

Permit fees where required (most attic work doesn't require one)

Warranty on workmanship (typically 1-5 years) and materials (manufacturer)

What raises the price

Attic access (pull-down stairs vs. scuttle hole vs. crawl)

Removing damaged or contaminated insulation first

Knob-and-tube wiring (some products can't be installed over it)

Steep or low-slope roofs (more labor for spray foam at the deck)

Coastal or remote markets where contractor density is lower

Reducing what you pay

Federal 25C credit: 30% of materials, up to $1,200/year

State HEEHRA rebates: up to $1,600 if income-qualified

Utility rebates: $200-$1,750 depending on provider

Bundle air sealing + insulation in one project — most rebates require both, and it's cheaper than two trips