What does attic insulation really cost?
Published national pricing puts blown-in attic insulation at roughly fifty cents to two dollars and change per square foot, installed. Here's the math, what pushes it up, and who helps pay.
Cost per square foot, installed
National ranges from contractor-marketplace pricing. Labor and access matter as much as the material.
| Material | Installed range | Notes |
|---|---|---|
| Blown-in cellulose | $0.60–$2.30 / sq ft | The retrofit default: fills gaps, buffers moisture, cheapest per R |
| Blown-in fiberglass | $0.50–$2.00 / sq ft | Slightly cheaper, slightly lower performance per inch |
| Fiberglass batts | $0.90–$4.00 / sq ft | Published ranges disagree ($0.90–$1.80 vs $2–$4 installed) — get the line item quoted |
What moves the price
Removal of old insulation
Compressed, wet, or pest-contaminated material has to come out — a real labor line that top-up jobs skip entirely.
Air sealing first
The attic floor gets sealed before the insulation goes in — always. Often quoted separately; never let it be skipped. Here's what you can DIY.
R-value target
Northern climates call for R-49 to R-60 — over a foot of loose fill. Going from R-10 to R-60 costs more material than topping R-38 up. Details in the attic insulation guide.
Access and safety items
Tight hatches, kneewalls, ventilation baffles, dams around chimneys, covers for recessed lights, rerouting bath fans — the unglamorous items that separate a real quote from a teaser price.
This is the most-subsidized work in home energy
State and utility efficiency programs love insulation because it's cheap heat savings — many cover 40–100% of envelope work. Where states have launched the federal HEAR program, income-eligible households can additionally get up to $1,600 toward insulation, air sealing, and ventilation — but launch status varies by state and several programs are income-restricted, so check yours rather than assuming.
Strong-program states in the Northeast — Massachusetts, Maine, Connecticut, New York — routinely cover the majority of insulation costs through their efficiency programs. Your state page has the specifics, and the Rebate Matcher finds what you qualify for.
Attic insulation cost questions
How much does it cost to insulate a 1,500 sq ft attic?
With blown-in cellulose at published national rates of $0.60–$2.30 per square foot installed, a 1,500 sq ft attic runs roughly $900–$3,450 before rebates. Topping up an accessible attic sits near the low end; removal of old insulation, air sealing, and deep R-60 targets push toward the high end.
Is blown-in insulation cheaper than batts?
For attic retrofits, usually yes — and it performs better in real attics because it fills around framing, wires, and odd cavities that batts leave exposed. Batts shine in open new-construction bays, which is not what a retrofit is.
Does attic insulation increase home value?
It consistently ranks among the highest-ROI home improvements because the cost is modest and the energy savings are immediate and permanent. Buyers and appraisers increasingly look at energy costs; a documented insulation upgrade with a post-work assessment report is a sellable asset.
Can I insulate my attic myself?
Blowing loose fill is physically doable with a rented machine, but the value is in what happens first: air sealing the attic floor, fixing ventilation, and handling safety items like recessed lights and bath fans. Most DIY attic jobs skip those steps and lock in the leaks. If you DIY anything, DIY the prep research — then decide.
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Before you get quotes, know what your state pays.
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