Free Tool
Insulation Cost Calculator
Get an instant estimate for your insulation project. Choose your area, select your service type, and enter square footage. No contact information required.
Where do you need insulation?
Do you need old insulation removed?
How many square feet?
Enter square footage above to see your estimate
Pricing Factors
What Affects Insulation Cost
Area Type
Attic insulation is the most affordable. Crawl spaces cost more due to access and moisture. Walls require drilling and dense-packing.
Square Footage
Larger spaces cost more total but can bring the per-square-foot price down. A typical Seattle-area attic runs 1,000 to 1,500 sq ft.
Old Insulation Removal
If existing insulation is contaminated by rodents, mold, or moisture, it needs to come out first. Removal adds labor and disposal costs.
Material Choice
Blown-in fiberglass, cellulose, and batt insulation each carry different price points. We recommend the best fit during your free estimate.
Access & Layout
Tight crawl spaces, steep attic angles, and complicated framing add time and cost. We assess this during our free on-site visit.
Local Market Rates
Labor and material prices in the Seattle metro area, including Kent and Mountlake Terrace, reflect regional cost of living.
Price Reference
Insulation Cost Per Square Foot
Attic Insulation
Installation
$2.60 /sq ft
Removal Add-on
$0.90 /sq ft
Most common. Best for homes below R-49 code.
Crawl Space
Installation
$3.00 /sq ft
Removal Add-on
$0.90 /sq ft
Includes access challenges and moisture factors.
Wall Insulation
Installation
$2.60 /sq ft
Removal Add-on
N/A
Requires drilling and dense-pack technique.
Our Approach
How We Price Insulation Work
Green Attic provides line-item estimates for every insulation project. That means you see exactly what you are paying for: labor, materials, removal (if needed), and disposal listed separately. We do not bundle costs into a single lump sum or use vague "per project" pricing. When you compare our estimate against another contractor's, you can see where the money goes.
For mold-related work, we go a step further. Every mold remediation project includes independent third-party clearance testing performed by a separate lab, not by our own crew. This ensures the results are unbiased and verifiable. The testing cost is a separate line item on your estimate so you know exactly what that portion covers. We believe the company doing the remediation should never be the same company certifying the results.
Our pricing reflects the cost of working in King County and Snohomish County: local labor rates, proper disposal at licensed facilities, and materials that meet Washington State energy code. We also factor in rebate eligibility from Puget Sound Energy, Seattle City Light, and Snohomish County PUD, and we help every customer apply for the credits they qualify for. The calculator above gives you a realistic starting point. For an exact number with no surprises, schedule a free in-home estimate.
Save Money
Rebates & Tax Credits for Insulation
Utility Rebates
- Puget Sound Energy (PSE)
Rebates for attic and floor insulation in electrically heated homes
- Seattle City Light
Incentives for homes under-insulated by current code
- Snohomish County PUD
Rebates for qualifying projects in their service area
Federal Tax Credits
- Inflation Reduction Act
Up to 30% tax credit on insulation project costs, with a maximum of $1,200 per year
We help every customer identify which rebates apply to their project. During your free estimate, we outline your eligibility and help with the paperwork.
Coverage Area
Where We Install Insulation
South Snohomish County
Common Questions
Frequently Asked Questions
How accurate is this insulation cost calculator?
Our calculator gives you a realistic ballpark based on current per-square-foot pricing in King County and Snohomish County. Final costs can vary depending on access difficulty, existing insulation condition, and material choices. For an exact number, schedule a free in-home estimate.
What is the average cost to insulate an attic in the Seattle area?
For new attic insulation installation, expect to pay $2.60 per square foot. A typical 1,200 sq ft attic costs about $3,120. If old insulation needs to be removed first, add $0.90 per square foot for removal.
Does crawl space insulation cost more than attic insulation?
Yes, crawl space insulation generally costs a bit more. Crawl spaces are harder to access, often require moisture management, and may need vapor barriers. New crawl space insulation runs $3.00 per square foot.
Are there rebates available for insulation in Washington State?
Yes. Puget Sound Energy, Seattle City Light, and Snohomish County PUD all offer rebates for qualifying insulation upgrades. Federal tax credits through the Inflation Reduction Act may also apply. We help customers identify and apply for every rebate they qualify for.
Should I remove old insulation before installing new?
It depends. If existing insulation is contaminated by rodents, mold, or moisture, removal is recommended before installing new material. If the old insulation is clean and in decent shape, we can often blow new insulation on top to reach R-49 code. We assess this during every free estimate.
What R-value should my insulation be?
Washington State energy code requires R-49 for attic insulation in new construction and major upgrades. Many older homes in King County and Snohomish County fall well below this standard. During our free assessment, we measure your current R-value and show you what it takes to reach code.
How long does insulation installation take?
Most attic insulation jobs take one day. Crawl space insulation runs one to two days depending on size and condition. If old insulation needs to be removed first, add an extra day. We give you a clear timeline during your estimate.
Do I need to provide contact information to use the calculator?
No. Our insulation cost calculator is completely free to use with no email, phone number, or signup required. When you are ready for an exact quote, you can request a free in-home estimate at your convenience.
What types of insulation do you install?
We install blown-in fiberglass, blown-in cellulose, and fiberglass batt insulation. The best choice depends on your home, the area being insulated, and your budget. We explain the options during your free estimate and recommend the best fit.
Can insulation help with noise reduction?
Yes. Insulation reduces sound transmission between floors and through walls. Blown-in cellulose is particularly effective for noise reduction. If sound dampening is a priority, let us know during your estimate and we can factor that into our recommendation.
Want a precise quote?
Our calculator gives you a ballpark. For an exact number, schedule a free in-home estimate. No obligation, no pressure.
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WA License #GREENAL785CS
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Real homeowners across King and Snohomish County