Glass wool insulation, also called fiberglass insulation, typically costs $1-$3 per square foot installed, with a national planning average near $1.75. The final price depends on insulation type, target R-value, access, removal needs, project size, and local labor rates.
| Item | Low | Average | High | Notes |
|---|---|---|---|---|
| Installed fiberglass batts | $1.00 per sq ft | $1.75 per sq ft | $3.00 per sq ft | Open wall or attic framing; standard batts |
| Blown-in fiberglass | $1.00 per sq ft | $1.80 per sq ft | $3.25 per sq ft | Typical accessible attic, before removal or repairs |
| Attic insulation project | $1,000 | $2,200 | $5,000 | About 1,000-1,500 sq ft; depth and access vary |
| Whole-home insulation | $3,000 | $6,500 | $12,000 | Existing 1,500-2,000-sq-ft home; scope varies |
| Fiberglass material only | $0.40 per sq ft | $0.80 per sq ft | $1.50 per sq ft | Product, R-value, and package size affect retail price |
What Glass Wool Insulation Costs for Common Home Projects
For standard fiberglass batts installed between accessible framing, homeowners commonly pay $1-$3 per square foot. Blown-in fiberglass generally falls around $1-$3.25 per square foot in an open attic. These are broad U.S. ranges for routine work, not guaranteed quotes; tight spaces, high ceilings, air sealing, and old insulation removal can push totals higher.
A 1,000-square-foot attic often costs about $1,000-$3,250 for new blown-in insulation. A simple top-up over a clean, accessible attic may land near the low end, while a deep insulation target, difficult hatch, or prep work can move it toward the high end. At 1,500 square feet, a similar project may run roughly $1,500-$4,875.
Material-only pricing is lower than installed pricing. Fiberglass batts often cost about $0.40-$1.50 per square foot, depending on thickness, facing, and R-value. Loose-fill fiberglass is commonly priced around $0.30-$0.90 per square foot for the material at typical attic depths. Contractors may quote by square foot, bag, or project, so the estimate should identify the coverage rate and intended installed depth.
Assumptions: Standard fiberglass products, ordinary access, no major framing repair, and typical U.S. contractor pricing; regional labor and project scope can change totals.
How Batts, Blown-In Material, and Labor Shape the Quote
A contractor’s quote usually combines insulation product, installation labor, equipment, and any preparation or disposal. The proportions vary: a straightforward attic may have modest labor, while wall cavities or overhead work require more time per square foot. Ask whether the quote includes air sealing, baffles, cleanup, and protection around fixtures.
| Quote component | Typical price | What changes the charge | Common billing basis |
|---|---|---|---|
| Fiberglass batts | $0.40-$1.50 per sq ft | R-value, facing, width, and product grade | Per sq ft or package |
| Blown-in fiberglass | $0.30-$0.90 per sq ft material | Installed depth, coverage, and bag count | Per bag or sq ft |
| Installation labor | $0.50-$1.75 per sq ft | Access, framing, slope, and crew productivity | Per sq ft or hourly |
| Blower and setup | $100-$400 per project | Rental, delivery, minimum charge, or contractor equipment | Flat fee or included |
| Removal and disposal | $1-$2.50 per sq ft | Insulation condition, bagging, access, and disposal fees | Per sq ft or project |
Labor for insulation work may equate to about $50-$100 per worker-hour, although many contractors price by area rather than time. For an itemized labor estimate, gives the basic calculation before equipment, overhead, and other charges. A minimum service fee can make small repairs expensive relative to the area treated.
Compare the included work, not just the per-square-foot number. One bid may include air sealing and cleanup while another prices those tasks separately. For batt installations, confirm whether cutting around wiring and pipes is included and whether the installer will maintain contact with the air barrier without compressing the insulation.
Which R-Value, Cavity Depth, and Access Conditions Raise Price?
Target R-value is a major price driver because higher performance generally requires more material and, in some cases, deeper framing or multiple layers. For example, attic projects aiming for roughly R-30 may use less material than jobs targeting R-49 or R-60. The right target depends on climate zone, existing insulation, and local energy requirements; a contractor should state the installed R-value, not only the product label.
Framing depth determines whether batts fit correctly. A 3.5-inch wall cavity commonly takes a different batt than a 5.5-inch cavity, and a thicker product should not be forced into a shallow space. Compressing fiberglass reduces its effective performance. Where the required R-value exceeds cavity capacity, the estimate may include layered insulation, raised attic decking, or another assembly, adding labor and materials.
Attic area also matters. A 500-square-foot attic may carry a minimum charge, while a 2,000-square-foot open attic can benefit from more efficient crew setup. Roof pitch, low clearance, narrow hatches, and joists covered with storage platforms can slow work. A roof slope above about 6:12 or a crawlspace clearance under 18 inches can require extra handling or a different installation approach.
Existing conditions can create scope changes. Wet or pest-damaged insulation should be addressed before new material is installed; wiring, recessed lights, chimneys, and exhaust ducts may need clearance or protective measures. Air leaks around plumbing penetrations and attic hatches are not solved by adding insulation alone. Ask for separate prices for insulation depth, air sealing, and any safety or repair work.
How Long Batts and Attic Blowing Take to Install
A two-person crew may complete a straightforward 1,000-square-foot open attic in about 3-6 hours, including setup and basic cleanup. Adding insulation over existing material is often faster than removing old insulation first. A 1,000-square-foot batt installation in open new-construction framing may take roughly 6-12 crew-hours, depending on the number of cuts and obstacles.
Existing walls are more time-consuming because installers may need to open and patch drywall, drill access holes, or use specialized equipment to fill closed cavities. A small wall retrofit might take a day or longer once setup and repairs are included. These time estimates describe ordinary conditions; a contractor’s schedule can change with crew size, home layout, weather, and material availability.
For hourly work, rates often fall around $50-$100 per worker-hour, while some markets charge more for licensed specialty labor or small jobs. Many insulation companies instead set a project price based on measured area and difficulty. Confirm whether travel, setup, equipment, and cleanup are included before comparing an hourly quote with a flat-rate bid.
Assumptions: Two-person crew, clear work area, standard access, and no extensive removal, drywall repair, or electrical work.
Why Glass Wool Prices Differ Across U.S. Regions
Labor markets, building density, travel distance, and disposal rules produce meaningful regional differences. As a rough planning adjustment, metropolitan markets in the Northeast and West Coast may run 10%-25% above the national midpoint. Many Midwest and Southern markets fall near the midpoint, while rural areas can be 5%-15% lower on labor but may incur a trip or minimum charge.
These percentages are approximate comparisons, not a fixed regional price list. A busy city contractor may charge more because of parking, building access, and labor demand; a rural estimate may be higher if the crew travels a long distance or the project is small. Local climate recommendations can also change the amount of insulation needed, raising total material cost even when the per-square-foot labor rate is moderate.
When checking bids, compare the same R-value, coverage area, and removal scope. A quote for R-49 at a specified depth is not directly comparable with one for a shallower top-up. Request the product type, bag count or batt specification, installed depth, and total area in writing. Those details make it easier to tell a regional rate difference from a true difference in scope.
Three Example Quotes for Attics and Wall Cavities
A basic quote illustrates why project size and preparation matter. These examples use plausible U.S. pricing and standard fiberglass products; actual offers vary with region, access, and contractor minimums.
| Project | Scope and unit rate | Estimated total | Price notes |
|---|---|---|---|
| Small attic top-up | 600 sq ft at $1.50-$2.25 per sq ft | $900-$1,350 | Open access, existing insulation retained, modest setup |
| Standard attic upgrade | 1,200 sq ft at $1.75-$2.75 per sq ft | $2,100-$3,300 | Blown-in fiberglass, deeper target, basic air sealing |
| Removal and replacement | 1,000 sq ft at $2.75-$5.25 per sq ft | $2,750-$5,250 | Old material bagged and removed, then new insulation installed |
For a more detailed example, a 1,200-square-foot attic might include $500-$1,000 of fiberglass, $800-$1,400 for installation, and $200-$500 for setup and air sealing. If removal is necessary, another $1,000-$2,500 may be added. The total could therefore range from about $1,500-$2,900 without removal to $2,500-$5,400 with it.
Wall-cavity work is less predictable because access and patching can dominate the price. For a 500-square-foot section of open framing, batt material and installation may cost around $500-$1,500. Closed-wall retrofit work can cost more after drilling, cavity filling, and drywall repair; compare the insulation price separately from painting or finish restoration.
Cut the Insulation Bill by Controlling Scope and Prep
Measure the attic or wall area before requesting bids, then ask each contractor to price the same square footage and R-value. If existing insulation is dry, clean, and undamaged, adding material over it may avoid removal charges. Do not cover wet or contaminated material, and do not assume old insulation has the correct depth or even coverage.
Clear stored items and provide safe access to the attic hatch before the crew arrives. This can reduce billed setup time and prevent a labor surcharge. Ask whether basic air sealing is included and prioritize leaks around penetrations and hatches before paying for a larger insulation depth. A contractor should identify any electrical, moisture, or ventilation issue that needs attention first.
Compare at least three itemized estimates and check that each specifies product, R-value, installed depth, removal, disposal, air sealing, and cleanup. For a new build with open framing, batts may be less costly than a retrofit that requires cavity access. For an open attic, blown-in material can be efficient around joists and obstructions. Choose based on cavity fit and performance as well as price.
Avoid paying for an upgrade that does not solve the home’s actual insulation gap. Ask for a base quote and a separately priced higher-R-value option, then compare the added cost with the additional material and depth. Keep the work area accessible, confirm the agreed scope in writing, and check whether permits or inspection fees apply locally before accepting the final estimate.
Removal, Air Sealing, and Other Charges to Check
Old insulation removal commonly adds $1-$2.50 per square foot, and heavily soiled, damp, or pest-affected material may cost more to handle. Disposal, bagging, and protective equipment can be separate line items. Ask how the contractor will protect the home from dust and whether the removal price includes hauling and disposal at an approved facility.
Air sealing may add about $200-$1,000 for an attic, depending on the number and size of gaps and the materials used. Sealing a few obvious penetrations can cost less than a broad treatment around top plates, plumbing openings, ductwork, and the attic hatch. Baffles, damming around fixtures, and ventilation corrections may add roughly $2-$8 per linear foot or $50-$300 per location.
Other possible charges include a $75-$200 inspection or diagnostic fee, a small-job minimum of $250-$600, and delivery or equipment fees of $50-$250. Permit requirements vary by location and project scope; when required, fees may be roughly $50-$300, though local rules differ. New construction, major alterations, and energy-code compliance can involve inspections or additional documentation.
Assumptions: Add-on ranges cover ordinary residential work; hazardous materials, major repairs, and unusually difficult access require separate evaluation.