Attic Insulation Cost: Types, Pricing, and Savings (2026)
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💰 Cost Breakdown
| Item | Low | Average | High |
|---|---|---|---|
| Blown-In Fiberglass (R-38 to R-49) Loose fiberglass fibers blown into the attic floor to fill gaps and build up to current code depth (10–14 inches). The most common choice for unfinished attics. Fast installation — most homes done in 2–4 hours. | $1,000 | $1,800 | $2,800 |
| Blown-In Cellulose (R-38 to R-49) Recycled paper fiber treated with fire retardant, blown in to similar depths as fiberglass. Slightly better air-sealing properties and lower cost in some markets. Settles 10–15% over time, so installers add extra depth. | $900 | $1,600 | $2,500 |
| Fiberglass Batt (R-30 to R-38) Pre-cut fiberglass blankets laid between joists. DIY-friendly but less effective than blown-in because batts leave gaps at joists, wiring, and plumbing penetrations. Best for open, accessible attics with standard joist spacing. | $700 | $1,200 | $2,000 |
| Open-Cell Spray Foam (R-19 to R-38) Sprayed onto the underside of the roof deck to create a sealed, conditioned attic. Expands to fill every gap. R-3.5–3.7 per inch. Used when the attic contains HVAC equipment or ductwork. | $2,500 | $4,000 | $6,000 |
| Closed-Cell Spray Foam (R-30 to R-49) Dense foam with R-6.5–7.0 per inch. Acts as both insulation and vapor barrier. Highest performance but highest cost. Typically used in combination — 2–3 inches of closed-cell topped with blown-in or open-cell. | $4,000 | $6,500 | $10,000 |
| Radiant Barrier Reflective foil stapled to the underside of roof rafters. Reduces radiant heat transfer by 40–50%. Most effective in hot climates (cooling-dominated homes). Does not replace traditional insulation — it supplements it. | $500 | $1,000 | $1,800 |
| Old Insulation Removal Vacuuming out old, compressed, or contaminated insulation before installing new material. Required when existing insulation is damaged by water, pests, or mold. | $1,000 | $1,800 | $3,000 |
Blown-In Fiberglass (R-38 to R-49)
Loose fiberglass fibers blown into the attic floor to fill gaps and build up to current code depth (10–14 inches). The most common choice for unfinished attics. Fast installation — most homes done in 2–4 hours.
Blown-In Cellulose (R-38 to R-49)
Recycled paper fiber treated with fire retardant, blown in to similar depths as fiberglass. Slightly better air-sealing properties and lower cost in some markets. Settles 10–15% over time, so installers add extra depth.
Fiberglass Batt (R-30 to R-38)
Pre-cut fiberglass blankets laid between joists. DIY-friendly but less effective than blown-in because batts leave gaps at joists, wiring, and plumbing penetrations. Best for open, accessible attics with standard joist spacing.
Open-Cell Spray Foam (R-19 to R-38)
Sprayed onto the underside of the roof deck to create a sealed, conditioned attic. Expands to fill every gap. R-3.5–3.7 per inch. Used when the attic contains HVAC equipment or ductwork.
Closed-Cell Spray Foam (R-30 to R-49)
Dense foam with R-6.5–7.0 per inch. Acts as both insulation and vapor barrier. Highest performance but highest cost. Typically used in combination — 2–3 inches of closed-cell topped with blown-in or open-cell.
Radiant Barrier
Reflective foil stapled to the underside of roof rafters. Reduces radiant heat transfer by 40–50%. Most effective in hot climates (cooling-dominated homes). Does not replace traditional insulation — it supplements it.
Old Insulation Removal
Vacuuming out old, compressed, or contaminated insulation before installing new material. Required when existing insulation is damaged by water, pests, or mold.
📊 Factors That Impact Cost
Attic Size
High ImpactCosts scale roughly linearly with square footage. A 1,000 sq ft attic costs about half as much as a 2,000 sq ft attic for the same material and R-value. Measure your attic footprint to get accurate quotes.
Insulation Type
High ImpactBlown-in fiberglass or cellulose costs $1.00–$2.50/sq ft installed. Open-cell spray foam runs $2.50–$4.00/sq ft. Closed-cell spray foam is $4.00–$7.00/sq ft. The right type depends on your climate, attic use, and budget.
Existing Insulation Condition
Medium ImpactIf existing insulation is dry and clean, new material can be blown on top. If it's wet, moldy, or pest-damaged, removal adds $1,000–$3,000 before new insulation goes in.
Air Sealing
Medium ImpactProfessional air sealing of gaps around wiring, plumbing, recessed lights, and the attic hatch adds $300–$800 but can improve insulation performance by 15–25%. Many contractors include basic air sealing in their insulation bids.
Accessibility
Medium ImpactA wide-open attic with a pull-down stair is easy to insulate. Tight spaces, low clearance, or no permanent access point add labor time and cost — sometimes 20–40% more.
Climate Zone
Low ImpactThe Department of Energy recommends R-38 for mild climates and R-49 to R-60 for cold climates. Higher R-value means more material. The difference between R-38 and R-60 in blown-in fiberglass is about $400–$800 for a typical attic.
💡 Money-Saving Tips
Start with air sealing before adding insulation
Sealing gaps and cracks in the attic floor before adding insulation makes the insulation 15–25% more effective. A tube of fire-rated caulk and a can of expanding foam cost $20 and address the biggest energy leaks.
Top up existing insulation instead of replacing
If your current insulation is clean and dry but just too thin, blowing new material on top is much cheaper than removing and replacing. Going from R-19 to R-49 by topping up costs $800–$1,500 vs. $2,000–$4,000 for full replacement.
Claim federal tax credits and utility rebates
The Inflation Reduction Act provides a 30% tax credit (up to $1,200) on insulation installed by a contractor. Many utilities offer additional rebates of $200–$500. Combined, these can offset 30–50% of the project cost.
Install fiberglass batts yourself
If your attic has standard 16-inch or 24-inch joist spacing and good access, laying batt insulation is a DIY-friendly weekend project. Material costs $0.30–$0.80/sq ft vs. $1.00–$2.50/sq ft installed.
Get quotes in spring or fall
Insulation contractors are busiest during extreme weather seasons (mid-summer and mid-winter) when homeowners feel the pain. Scheduling in spring or fall often means faster service and 5–10% lower pricing.