Attic Insulation Cost: 2026 Prices by Material & R-Value
Attic Insulation Cost: 2026 Prices by Material & R-Value
The attic is where most homes lose the most heat — and where insulation delivers the fastest payback. The DOE estimates that upgrading from R-19 to R-49 saves $200–$400/year on heating and cooling for a 1,500 sq ft home. At $1,200–$3,000 for a professionally blown-in job, that's a 2–5 year payback — better than almost any other home improvement. This guide breaks down every cost you'll encounter so you can budget accurately.
Quick Answer: For a 1,000 sq ft attic, expect $1,200–$3,500 for blown-in (cellulose or fiberglass) or $3,000–$7,000 for spray foam (roof deck). DIY blown-in cuts cost to $600–$1,100. Adding air sealing runs $500–$1,500 extra but saves an additional 10–20% on energy bills. All prices are 2025–2026 national averages.
Table of Contents
- Cost by Material
- Cost by R-Value Target
- DIY vs Professional Cost
- Air Sealing Cost
- Old Insulation Removal Cost
- Factors That Affect Cost
- Is Attic Insulation Worth It?
- How to Save Money
- How to Get Accurate Quotes
- Common Mistakes
- Key Takeaways
- FAQ
Cost by Material
All costs for a 1,000 sq ft attic, professionally installed (2025–2026 national averages).
| Material | Cost Range | Average | R-Value Achieved |
|---|---|---|---|
| Blown-in cellulose | $1,200–$3,500 | $2,200 | R-38 to R-60 |
| Blown-in fiberglass | $1,200–$2,800 | $2,000 | R-38 to R-49 |
| Fiberglass batts (DIY typical) | $800–$2,000 | $1,200 | R-30 to R-49 |
| Spray foam — open-cell (roof deck) | $3,000–$5,000 | $4,000 | R-19 to R-23 |
| Spray foam — closed-cell (roof deck) | $4,500–$7,000 | $5,500 | R-21 to R-30 |
Additional costs that may apply:
| Add-On | Cost Range | Average |
|---|---|---|
| Air sealing | $500–$1,500 | $900 |
| Old insulation removal | $1,000–$2,000 | $1,500 |
The math is straightforward: blown-in insulation on the attic floor delivers R-49 to R-60 for $1,200–$3,500. Spray foam on the roof deck costs $3,000–$7,000 for R-19 to R-30. For standard unconditioned attics, blown-in wins on value. Spray foam is justified only when creating a conditioned attic (when HVAC ductwork runs through the attic space).
For a detailed comparison of all insulation types, the types of insulation page has full pricing and performance data.
Cost by R-Value Target
This is the most useful table for budgeting a blown-in cellulose attic job — the most common approach.
Blown-In Cellulose, 1,000 sq ft Attic (2025–2026)
| Target R-Value | Settled Depth | Bags Needed | Material Cost | Installed Cost |
|---|---|---|---|---|
| R-30 | 8.5–9" | 18–22 | $360–$660 | $800–$2,000 |
| R-38 | 10.5–11" | 23–28 | $460–$840 | $1,000–$2,500 |
| R-49 | 13.5–14.5" | 30–36 | $600–$1,080 | $1,200–$3,000 |
| R-60 | 16.5–17.5" | 37–43 | $740–$1,290 | $1,500–$3,500 |
Going from R-30 to R-49 adds roughly $200–$400 in material and $400–$1,000 to the installed price for a 1,000 sq ft attic. That incremental investment saves an additional $50–$100/year in energy costs — a 2–4 year payback on the upgrade alone. We recommend R-49 minimum for climate zones 2+ and R-60 for zones 4+ if budget allows. Check our R-30 vs R-38 vs R-49 comparison for the full value analysis.
Bags run approximately $12–$15 each at Home Depot and Lowe's ($20–$30 per bag for GreenFiber, Owens Corning, or equivalent). Bag count varies by manufacturer — always check the coverage chart printed on the bag for your specific product.
DIY vs Professional Cost
| Approach | Cost (1,000 sq ft to R-49) | Savings vs Pro |
|---|---|---|
| Professional blown-in cellulose | $1,200–$3,000 | Baseline |
| Professional blown-in fiberglass | $1,200–$2,800 | Baseline |
| DIY blown-in cellulose | $600–$1,100 | 40–60% savings |
| DIY blown-in fiberglass | $500–$900 | 45–65% savings |
DIY blown-in insulation is one of the most accessible and cost-effective home improvement projects. Machine rental runs ~$100/day, but most home centers offer free machine rental with purchase of 20+ bags of insulation. At 30–36 bags for R-49 (1,000 sq ft), you'll easily qualify.
DIY time estimate: 4–8 hours for two people (not counting air sealing). Add 4–6 hours for thorough air sealing of the attic floor before insulating.
When DIY makes sense: Open, accessible attic with standard joist framing, adequate headroom, no knob-and-tube wiring, no vermiculite, and reasonable comfort working in attic conditions.
When to hire a pro: Complex multi-level attics, significant air sealing work needed, existing moisture/mold problems, knob-and-tube wiring, vermiculite (potential asbestos), very limited access, or physical limitations.
Step-by-step guidance at how to insulate an attic and how to install blown-in insulation.
Pro Tip: The biggest DIY savings come from combining air sealing and insulation yourself. Professional air sealing runs $500–$1,500. DIY air sealing costs $100–$300 in caulk, canned foam, weatherstripping, and baffles. That's $400–$1,200 saved on air sealing alone, plus $600–$1,900 saved on insulation labor — total DIY savings of $1,000–$3,000 on a complete attic project.
Air Sealing Cost
| Approach | Cost | What's Included |
|---|---|---|
| Professional air sealing | $500–$1,500 | Seal all penetrations, top plates, duct boots, recessed lights, attic hatch |
| DIY air sealing | $100–$300 | Caulk, canned foam, weatherstripping, baffles (materials only) |
Air sealing the attic floor before insulating adds significant cost — but it's the highest-return component of the entire project. The DOE estimates that air sealing alone saves 10–20% on heating and cooling. Combined with insulation, the total reduction is 15–25%.
Skipping air sealing to save $500–$1,500 leaves money on the table every month. On a $2,000/year energy bill, 10% additional savings from air sealing = $200/year — the professional air sealing pays for itself in 2.5–7.5 years on top of the insulation savings. Building Science Corporation's research confirms that air leakage is the dominant heat loss mechanism in most residential attics.
Our air sealing vs. insulation guide explains the science, and the how to air seal an attic page walks through the DIY process step by step.
Old Insulation Removal Cost
| Scenario | Cost | Recommendation |
|---|---|---|
| Old insulation in good condition | $0 | Leave it. Blow new insulation over it. R-values are additive. |
| Wet, moldy, or contaminated | $1.00–$2.00/sq ft ($1,000–$2,000 for 1,000 sq ft) | Remove, remediate moisture source, then re-insulate. |
| Pest-damaged (rodents, insects) | $1.00–$2.00/sq ft + sanitizing | Remove, sanitize, seal entry points, then re-insulate. |
| Vermiculite (potential asbestos) | $3.00–$8.00/sq ft (professional abatement) | Have tested first. If asbestos-positive, professional abatement required before any work. |
| Good condition but need access for air sealing | $1.00–$2.00/sq ft | Worth removing to do thorough air sealing, then re-insulate. Gold standard approach. |
In most cases, you can blow new insulation directly over existing material — no removal needed. If old insulation has kraft facing, slash it (don't remove it) so moisture can pass through rather than getting trapped between layers.
Factors That Affect Cost
Square footage — The biggest variable. Costs scale linearly with area, though larger projects benefit from slightly lower per-square-foot rates due to fixed mobilization costs.
Estimated Total Cost by Attic Size (Blown-In Cellulose to R-49)
| Attic Size | DIY Cost | Professional Cost |
|---|---|---|
| 500 sq ft | $350–$600 | $700–$1,600 |
| 750 sq ft | $475–$825 | $900–$2,200 |
| 1,000 sq ft | $600–$1,100 | $1,200–$3,000 |
| 1,500 sq ft | $900–$1,600 | $1,800–$4,200 |
| 2,000 sq ft | $1,200–$2,100 | $2,400–$5,500 |
| 2,500 sq ft | $1,500–$2,600 | $3,000–$6,800 |
Attic access — Easy access (pull-down stairs, large scuttle hatch): standard pricing. Difficult access (tiny hatch, low headroom, multi-level): add 10–20% for time and complexity. If the access point is through a bedroom closet, expect additional care costs for protecting the home.
Material choice — Blown-in cellulose and fiberglass are nearly identical in cost ($0.60–$2.30 vs $0.50–$2.00/sq ft). Spray foam is 2–5× more. Fiberglass batts are cheapest on material but slower to install.
Existing insulation — Adding over existing insulation: no extra cost. Removing old insulation first: add $1.00–$2.00/sq ft. In most cases, you can blow new insulation directly over existing material. Removal is only necessary for contaminated, wet, or vermiculite insulation. Our attic insulation guide covers when removal is warranted.
R-value target — Going from R-30 to R-49 adds ~30% to material cost but only ~15–20% to installed cost (labor is the same). We recommend always targeting R-49 minimum in climate zones 2+ — the marginal material cost for extra R-value is small compared to the labor you're already paying for.
Geographic region — Northeast and West Coast: 10–20% above averages. Southeast and Midwest: at or below averages. The insulation cost per square foot page has regional data.
Scope of air sealing — Quick spot-sealing of obvious gaps: $200–$500. Comprehensive professional air sealing: $500–$1,500. We always recommend adding air sealing to any attic insulation project — the energy savings from sealing leaks often exceed the savings from the insulation itself.
Spray Foam vs Blown-In: Is the Premium Worth It for Attics?
The single biggest cost decision for attic insulation is whether to use blown-in (cellulose or fiberglass) or spray foam. Here's a direct cost comparison for the same 1,000 sq ft attic targeting equivalent thermal performance.
| Blown-In Cellulose (R-49) | Open-Cell Spray Foam (R-38) | Closed-Cell Spray Foam (R-49) | |
|---|---|---|---|
| Material + labor | $1,200–$3,000 | $3,000–$5,500 | $5,500–$8,000 |
| Air sealing included? | No (add $500–$1,500) | Yes (built in) | Yes (built in) |
| Total cost | $1,700–$4,500 | $3,000–$5,500 | $5,500–$8,000 |
| Best for | Vented attics (standard) | Unvented/conditioned attics | Unvented attics, extreme climates |
For most standard vented attics, blown-in cellulose or fiberglass plus separate air sealing delivers excellent performance at roughly half the cost of spray foam. Spray foam makes financial sense primarily in unvented or conditioned attic assemblies where the roof deck needs insulation, or in situations where HVAC ductwork runs through the attic and bringing the attic inside the thermal envelope protects duct efficiency. Our spray foam insulation cost guide breaks down the full pricing picture, and the open-cell vs closed-cell comparison covers which type to use where.
For the typical homeowner insulating a standard vented attic, we recommend blown-in insulation with thorough air sealing. It's the highest-ROI approach, and it's the one project where DIY can save you 40–60%. Reserve spray foam for situations where the building science demands it — not as a default upgrade.
Is Attic Insulation Worth It?
Short answer: attic insulation is the most cost-effective energy upgrade for most homes. Here's the math.
Scenario: 1,500 sq ft ranch, climate zone 5, current attic insulation R-19 (6" of old fiberglass), upgrading to R-49 with blown-in cellulose.
| Line Item | Amount |
|---|---|
| Material (R-30 of cellulose over existing R-19) | $450–$800 (DIY) |
| Professional air sealing | $500–$1,500 |
| Total investment (DIY insulation + pro air sealing) | $950–$2,300 |
| Annual energy savings (DOE estimate) | $200–$400/year |
| Payback period | 2.4–5.8 years |
After payback, you save $200–$400 every year for the 20–30+ year effective lifespan of the insulation. That's $4,000–$12,000 in cumulative savings. Heating and cooling represent 50–70% of the average US energy bill (~$2,000/year nationally), and insulation + air sealing reduce those costs by 15–25%.
The ROI gets even better with available incentives. Energy Star and various federal, state, and utility programs offer rebates and tax credits that can offset 10–30% of project costs.
Pro Tip: If your attic currently has less than 6 inches of insulation (approximately R-19 or less), the ROI on upgrading is exceptional — you're starting from a low baseline where every inch of new insulation makes a big difference. If you already have 10–12 inches (R-30+), the diminishing returns curve kicks in. The upgrade from R-30 to R-49 saves less per year than R-19 to R-49, so payback extends to 4–8 years. Still worth it — just set expectations accordingly.
How to Save Money
- DIY blown-in insulation: $600–$1,100 vs $1,200–$3,000 professional — 40–60% savings.
- Free machine rental: Purchase 20+ bags at Home Depot or Lowe's to qualify.
- DIY air sealing: $100–$300 in materials vs $500–$1,500 professional.
- Don't remove old insulation unless it's contaminated. Blow new material over existing.
- Target R-49 minimum in zones 3+ — the marginal cost over R-30 is small ($200–$400 extra) but savings are significant.
- Time it right: Late fall and early spring are slower seasons for insulation contractors — some offer 5–15% discounts.
- Check rebates: Federal tax credits, state rebates, and utility programs can offset 10–30% of costs. Energy Star's database lists available programs by ZIP code.
- Combine projects: If a contractor is already on-site for attic work, adding rim joist insulation or sealing the attic hatch costs marginally more.
How to Get Accurate Quotes
- Get 3+ quotes for professional work. Pricing varies 20–40% between contractors.
- Specify the R-value target, not just "insulate my attic." R-30 is half the material of R-60.
- Ask whether air sealing is included or a separate line item. Many insulation contractors offer bundled pricing.
- Verify what's included: Material, labor, cleanup, baffles at eaves, depth verification.
- Red flags: No mention of air sealing, no on-site visit before quoting, quoting by phone only (they can't assess access or existing conditions without seeing the attic).
Common Mistakes
1. Skipping air sealing. Insulating without air sealing the attic floor first leaves 10–20% of potential savings on the table — $200–$400/year on a $2,000 annual energy bill. Air sealing adds $500–$1,500 (or $100–$300 DIY) and pays for itself in 1–3 years.
2. Under-insulating to save money. Going from R-30 to R-49 costs only $200–$400 more in material for a 1,000 sq ft attic. The energy savings from the additional R-value are $50–$100/year — a 2–4 year payback on the incremental cost. Don't leave R-value on the table when the marginal cost is this low.
3. Choosing spray foam for an unconditioned attic floor. Spray foam on the attic floor costs $3,000–$7,000 for 1,000 sq ft — versus $1,200–$3,500 for blown-in insulation that achieves higher R-values. Spray foam makes sense on the roof deck (conditioned attic) — not the floor.
4. Not accounting for removal costs. If old insulation needs to come out (contamination, moisture damage, vermiculite), budget an additional $1,000–$2,000 for 1,000 sq ft. Many homeowners get surprised by this add-on.
5. Ignoring signs of poor insulation. Uneven room temperatures, ice dams, high energy bills, and visible gaps in existing insulation all indicate the attic needs attention. Addressing these symptoms with proper air sealing + insulation is almost always cost-effective.
Key Takeaways
- A 1,000 sq ft attic: blown-in cellulose/fiberglass $1,200–$3,500 installed; spray foam (roof deck) $3,000–$7,000.
- DIY blown-in cellulose to R-49: $600–$1,100 (material + free machine rental). Savings: 40–60%.
- Air sealing adds $500–$1,500 professional ($100–$300 DIY) and saves an additional 10–20% on energy costs.
- Upgrading from R-19 to R-49 saves $200–$400/year with a 2–5 year payback — the best ROI of almost any home improvement.
- Going from R-30 to R-49 costs only $200–$400 more in material. Always target R-49 minimum in zones 3+.
- Old insulation removal costs $1.00–$2.00/sq ft — but is only needed for contaminated, wet, or asbestos-containing material. Most of the time, blow new material over existing.
- Spray foam is justified for conditioned attics with HVAC ductwork — not for standard unconditioned attic floors.
- Check rebates and tax credits — they can offset 10–30% of project costs.
FAQ
How much does attic insulation cost?
For a 1,000 sq ft attic: blown-in cellulose $1,200–$3,500, blown-in fiberglass $1,200–$2,800, fiberglass batts (DIY) $800–$2,000, spray foam $3,000–$7,000 (roof deck). Add $500–$1,500 for air sealing and $1,000–$2,000 if old insulation removal is needed. DIY blown-in cuts cost to $600–$1,100 with free machine rental. All prices are 2025–2026 national averages. The insulation cost calculator provides project-specific estimates.
Can I insulate my attic myself?
Yes — DIY blown-in attic insulation is one of the most accessible home improvement projects. You'll need a blowing machine (free rental with 20+ bag purchase), safety gear (N95 mask, glasses, long sleeves), and 4–8 hours with a helper. The main requirements: open accessible attic, standard joist framing, no knob-and-tube wiring, no vermiculite, and reasonable comfort working in the space. DIY saves 40–60% on installation cost. Step-by-step at how to insulate an attic.
Is attic insulation worth the investment?
Attic insulation is the highest-ROI energy upgrade for most homes. The DOE estimates $200–$400/year savings from upgrading to R-49 in a 1,500 sq ft home. At $1,200–$3,000 installed (or $600–$1,100 DIY), payback is 2–5 years. After payback, you save money every year for 20–30+ years. Heating and cooling account for 50–70% of the average US energy bill.
What R-value should I target?
Per the 2021 IECC: R-30 for zone 1, R-49 for zones 2–3, R-60 for zones 4–8. Energy Star recommends similar targets. Our recommendation: aim for at least R-49 in zones 2+ — the cost difference between R-30 and R-49 in blown-in material is only $200–$400 for 1,000 sq ft. Use our climate zone map to find your zone and the R-value chart for target values.
Should I remove old insulation before adding new?
Usually no. R-values are additive — blow new insulation directly over old material as long as it's dry, mold-free, pest-free, and not vermiculite (potential asbestos). If the existing insulation has kraft facing, slash it so moisture passes through. Remove old insulation only when it's wet, contaminated, heavily damaged, or when you need full access to the ceiling plane for comprehensive air sealing. Removal adds $1.00–$2.00/sq ft ($1,000–$2,000 for 1,000 sq ft).