Insulation costs range from about $0.80 to $7.50 per square foot installed, depending on material, thickness, access, and whether old insulation must be removed. For a typical 1,500-square-foot attic, homeowners commonly pay $1,500-$5,250 for fiberglass or cellulose, while spray foam can cost considerably more.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Fiberglass batts | $0.80/sq ft | $1.65/sq ft | $2.50/sq ft | Accessible walls, floors, or attic bays |
| Blown cellulose | $1.00/sq ft | $1.90/sq ft | $2.80/sq ft | Common for open attics |
| Mineral wool | $1.50/sq ft | $2.50/sq ft | $3.50/sq ft | Batts or boards, depending on application |
| Spray foam | $2.00/sq ft | $4.75/sq ft | $7.50/sq ft | Open-cell to closed-cell applications |
Installed insulation prices by material and attic size
For 1,500 square feet, fiberglass batts typically cost $1,200-$3,750, blown cellulose $1,500-$4,200, and spray foam $3,000-$11,250. Actual bids depend on the required R-value, depth, existing coverage, and whether the job is an attic, wall, crawl space, or basement.
For a standard, accessible attic, blown fiberglass or cellulose often provides the lowest installed price per square foot. Mineral wool generally costs more than basic fiberglass but may be selected for sound control or fire resistance. Rigid foam board is often priced at $2-$6 per square foot installed, with higher costs for specialized exterior or foundation work.
Assumptions: Approximate U.S. installed rates for ordinary access and standard residential materials; regional labor and project conditions change quotes.
What attic insulation quotes include beyond materials
Contractor estimates may include preparation, installation, equipment, and cleanup. Check whether the quote covers air sealing, old insulation removal, baffles, and disposal; these items can be excluded from a low base price.
| Quote item | Typical price | What changes the charge | Common billing basis |
|---|---|---|---|
| Insulation material | $0.50-$4.50 | Material type and R-value | Per sq ft |
| Installation labor | $0.40-$2.00 | Access, obstacles, and crew time | Per sq ft or job |
| Air sealing | $300-$1,500 | Number and size of gaps | Per attic or project |
| Removal and disposal | $1-$2.50 | Insulation depth and contamination | Per sq ft |
| Baffles and access work | $150-$800 | Vent count and hatch condition | Per project |
Labor often accounts for $0.40-$2.00 per square foot, with difficult access pushing the rate upward. Some contractors price labor within a bundled installed rate rather than listing it separately.
How R-value, attic depth, and access change the bill
Higher R-values require more material or thicker assemblies. In many U.S. climate zones, attic recommendations range around R-30 to R-60, but local code, existing insulation, and energy goals determine the appropriate target. Adding insulation over an existing layer may cost less than removing and replacing it.
For blown-in insulation, a shallow layer below 6 inches may require substantial added depth to reach a target R-value. Tight rafters, low roof clearance, stored belongings, and a small hatch can add labor or preparation charges. Spray foam thickness matters too: quotes should specify open-cell or closed-cell foam and inches installed, not only the area covered.
Compare bids at the same R-value and coverage depth, or the lower per-square-foot price may not deliver equivalent insulation.
Attic insulation rates in colder and warmer U.S. regions
Labor and material delivery can shift installed prices by roughly 10%-25% between lower-cost rural markets and higher-cost metropolitan areas. High-demand coastal cities may exceed national averages, while remote areas can also pay more because of travel and limited contractor availability.
Climate affects the recommended scope more than the material’s basic rate. Colder regions may need deeper attic coverage, increasing the total; hot climates may prioritize attic heat control and air sealing. Ask for the specified R-value and total square footage so regional quotes remain comparable.
Regional price differences are real, but matching the same material, R-value, and removal scope is essential for a fair comparison.
Three realistic insulation project estimates
A 1,000-square-foot open attic receiving blown cellulose at $1.50-$2.80 per square foot may total $1,500-$2,800, assuming no major removal or repairs. Installation may take a small crew several hours, with added air sealing priced separately.
A 1,500-square-foot attic with old insulation removed and new blown fiberglass installed could cost $3,000-$6,500. That estimate assumes removal at $1-$2.50 per square foot, new insulation, and ordinary access; damaged wiring or pest contamination can raise the price.
A 600-square-foot roof area treated with closed-cell spray foam at $4-$7.50 per square foot may cost $2,400-$4,500. The final bid depends on foam thickness, ventilation requirements, masking, and site setup.
Project totals reflect both area and scope; removal and specialty foam can make a smaller job cost more per square foot.
When insulation removal and air sealing add charges
Removing old insulation commonly adds $1-$2.50 per square foot, especially when material is deep, damp, or difficult to access. Suspected asbestos or significant pest contamination requires specialized assessment and handling, which is not included in routine removal rates.
Air sealing around penetrations, top plates, and attic hatches often adds $300-$1,500. It can reduce drafts and prevent conditioned air from leaking into the attic, but contractors should identify the work locations and materials rather than provide an unexplained lump sum.
Ask whether cleanup, disposal, ventilation baffles, and air sealing are included before treating a quote as complete.
Fiberglass, cellulose, and foam price trade-offs
Fiberglass batts can be economical in open, regularly spaced wall cavities, but gaps and compression reduce performance. Blown cellulose fills irregular attic spaces more easily and typically costs $1-$2.80 per square foot installed. Mineral wool is a higher-priced batt option at about $1.50-$3.50 per square foot.
Open-cell spray foam generally costs $2-$4.50 per square foot, while closed-cell foam runs about $3.50-$7.50. Foam can provide air sealing as part of the installation, but it may require specialized labor and careful attention to ventilation and building details.
Choose by installed performance and application, not by material price alone.
How to lower an insulation bill without cutting coverage
Keep the project focused on the areas that need improvement, and have the contractor measure coverage before quoting. Clearing stored items and ensuring safe access can reduce setup time. Compare at least three written estimates that state material, R-value, thickness, removal, air sealing, and disposal.
Adding insulation over sound existing material may cost less than full replacement. Avoid paying for a premium material where standard batts or blown-in insulation meet the project requirements, and ask whether combining attic work with nearby air sealing reduces a separate service charge.
Controlling scope and comparing equivalent specifications are more dependable savings than choosing the thinnest insulation option.