How much does attic insulation cost?

The cost of attic insulation can vary depending on the type of insulation, the size of the attic, and the labor involved. Here's a breakdown of the typical costs:

1. Cost by Insulation Type

Type of Insulation Cost Per Square Foot (Material + Installation)

Blown-in Fiberglass $1.00 - $2.50 Affordable, quick to install, good for most climates.

Blown-in Cellulose $1.20 - $2.80 Denser than fiberglass, better air sealing, eco-friendly.

Fiberglass Batt/Roll Insulation $0.80 - $2.50Easy for DIY, less effective in irregular spaces.

Spray Foam (Open-Cell) $1.50 - $4.90 Best air sealing, higher R-value, more expensive.

Spray Foam (Closed-Cell) $2.90 - $7.50 Highest R-value, moisture resistance, very costly.

Radiant Barrier $0.50 - $2.00 Reflects heat; often combined with other insulation.



Blown-in Fiberglass 1,000 sq. ft. $1,000 - $2,500

Blown-in Cellulose 1,000 sq. ft. $1,200 - $2,800

Spray Foam (Open-Cell) 1,000 sq ft $1,800 - $4,200

Costs include materials and professional installation.

3. Cost for DIY vs. Professional Installation

• DIY Installation (for batts/rolls or rented blowers):
• Materials: $0.50 - $1.50 per sq. ft.
• Equipment rental (blower for cellulose/fiberglass): $50 - $100 per day.
• Professional Installation: Includes labor and expertise, with costs typically 50-100% higher than DIY, but ensures proper coverage and quality and Avista and Inland Power rebate eligibility requires a contractor installation.

4. Factors Affecting Cost

1. R-Value Required: Higher R-values (e.g., R-49) require thicker insulation, increasing material costs.
2. Attic Accessibility: Difficult-to-reach attics or those with obstructions may increase labor costs.
3. Existing Insulation: Adding insulation over old material costs less than removing and replacing it.
4. Climate Zone: Colder climates often require more insulation, driving up costs.

5. Regional and National Averages

• National Average: $1,500 - $3,500 for a 1,000 sq. ft. attic.
• Low End: $800 for small attics with fiberglass batts.
• High End: $7,500+ for large attics with closed-cell spray foam.

6. Incentives and Rebates

Check for local rebates or federal tax credits for insulation upgrades. Programs like the Inflation Reduction Act may provide tax credits of up to 30% of costs for energy-efficient upgrades, including insulation.