Written by

Tara Farmer

October 4, 2023

Edited by

Kristen Cramer

Fact-checked by

Tom Grupa

Cost to insulate a house

Insulation costs $1.00 to $4.50 per square foot installed, depending on the type, material, R-value, and area. The average cost to insulate a house is $1,600 to $8,000. Insulation material prices are $0.50 to $2.80 per square foot, plus $0.50 to $1.70 per square foot for installation labor.

• Insulation replacement costs $2 to $8 per square foot, including old insulation removal.

• Some insulation companies have a $1,500 to $2,000+ minimum project fee.

Average insulation cost calculator

The following table reflects the average cost to insulate a house.

Home insulation installation costs by location

Wall insulation cost

Wall insulation costs $0.80 to $4.60 per square foot or $1,400 to $8,500 for all exterior walls in a house. Prices depend on the type, wall size, and whether new or existing construction. Fiberglass batts or blown-in insulation are the cheapest options. Injection foam and spray foam cost the most.

• Existing walls – Injection foam and blown-in insulation work best

• New construction or renovation – Batt and roll, rigid foam, and spray foam work best in exposed wall cavities.

Cost to insulate a garage

The cost to insulate a garage is $600 to $3,400, depending on the garage size and insulation type. DIY fiberglass batts in garage walls cost $100 to $720, while professional spray foam insulation for a 2-car garage costs $2,600 to $8,900.

• Only the exterior walls of an attached garage require insulation.

• An insulated garage door costs $1,500 to $3,700+.

• Garage door weather stripping costs $100 to $250.

Attic insulation prices

Attic insulation costs $1 to $4 per square foot or $1,000 to $2,700, depending on the insulation type and attic size and condition. Attic cleaning, air sealing, and old insulation removal may increase costs. Attic insulation options include blown-in, loose-fill, batt and roll, and spray foam.

• Unvented attic – Insulate the underside of the roof deck with spray foam, rigid foam, or reflective insulation.

• Vented attic – Insulate the attic floor with batts, spray foam, or blown-in insulation.

House roof insulation cost

Roof insulation costs $1.00 to $4.50 per square foot installed or $1,000 to $5,100, depending on the size, insulation type, and R-value. Insulating the roof and sealing the attic creates a conditioned space and reduces the load on attic-mounted HVAC equipment and ductwork.

Cost to insulate basement

Insulating a basement costs $1.20 to $2.90 per square foot installed or $600 to $4,600, depending on the size and insulation type. Spray foam and rigid foam board work best as they provide insulation and a vapor barrier to block moisture.

Crawl space and underfloor insulation

Crawl space insulation costs $1.00 to $4.50 per square foot installed or $500 to $3,700, depending on the insulation type. Combining rim joist and under-floor insulation is best for vented crawl spaces, while insulating the walls and rim joist is better for unvented areas.

Ceiling insulation cost

Ceiling insulation costs $1.20 to $3.00 per square foot installed or $240 to $1,500 per room. Insulating all the ceilings in an average home costs $2,400 to $7,500, depending on the type and R-value. Ceiling insulation options include batts, blown-in, loose-fill, spray foam, and rigid foam.

Cost to insulate a mobile home

Insulating a mobile home costs $0.50 to $3.50 per square foot or $700 to $5,000 on average, depending on the size, type, areas insulated, and whether DIY or professional installation. Insulation options include spray foam, blown-in, or blanket insulation.

Pole barn insulation cost

Pole barn insulation costs $1.00 to $4.50 per square foot or $3,500 to $16,500 installed, depending on the barn size and purpose, insulation type, and climate zone. Insulation options for pole barns include fiberglass batts, rigid foam, spray foam, or blown-in attic insulation.

Insulation cost per square foot by type

Insulation costs $0.30 to $4.50 per square foot installed, depending on the type, material, R-value, location, project size, and job complexity.

Cavity batt and roll insulation prices

Cavity batt and roll insulation prices are $0.80 to $2.60 per square foot installed, depending on the material and R-value. Batts and rolls come in fiberglass, cellulose, mineral wool, or natural fibers. Batt insulation is ideal for exposed wall or floor cavities and fits between wall studs, rafters, and joists.

Spray foam insulation

Spray foam insulation costs $1.00 to $4.50 per square foot installed, depending on the type, R-value, and project size. Open-cell spray foam only provides an air barrier. Closed-cell foam blocks air and moisture, ideal for below-grade applications like basements or crawl spaces.

Reflective or radiant barrier insulation

Radiant barrier installation costs $0.30 to $2.00 per square foot installed, depending on the type, attic size, and installation location. A radiant barrier blocks only radiant heat, while reflective insulation is a radiant barrier with an insulation layer that adds an R-value of R-3 to R-21.

Blown-in insulation

Blown-in insulation costs $1.00 to $2.80 per square foot installed, depending on the material, location, and R-value. Blown-in insulation is ideal for attics as the material fills gaps and odd-shaped spaces better than batts and rolls.

Rigid foam insulation boards cost

Rigid foam insulation costs $1.20 to $3.70 per board foot installed. Rigid foam is lightweight, easy to install, and a more effective insulator than traditional fiberglass. Extruded polystyrene (XPS) is the most common for residential applications.

New insulation prices by material

Insulation material prices range from $0.30 to $11.00 per square foot. Fiberglass batt insulation is the most common and DIY-friendly but requires replacing more often than durable, rigid materials like polystyrene or spray foam.

Fiberglass insulation cost

Fiberglass insulation costs $0.30 to $1.30 per square foot for the material alone, depending on the R-value and whether it is batt or blown-in. A roll of fiberglass insulation costs $20 to $90 and covers 40 to 75 square feet.

Insulation replacement cost factors

Insulation replacement costs $2 to $8 per square foot, including old insulation removal. Consider replacing insulation immediately if the home experiences water, fire, or pest damage. Damaged or wet insulation loses its R-value, becomes ineffective, and often leads to mold growth.

Factors affecting the cost include:

• Area size – Larger spaces require more materials and labor.

• Insulation type – Spray foam and rigid foam board cost the most. Fiberglass batt and roll insulation and blown-in cellulose cost the least.

• Faced vs. unfaced – Faced insulation costs $0.10 to $0.25 more per square foot than unfaced insulation. Some building codes require faced insulation in specific climate zones.

• R-value – The higher the R-value, the better the insulator. Colder regions, attics, ceilings, and roofs require higher R-values and thicker insulation, which costs more.

• New vs. existing construction – New home insulation costs less than insulating an existing home.

• Accessibility – Installing insulation in crawl spaces, odd-shaped attics, or finished drywall or siding increases labor costs.

• Repairs – Sagging or falling insulation may indicate moisture damage or rodent intrusion.

  • Handyman rates are $40 to $80 per hour on average for home repairs.

  • Hourly rates to hire an electrician are $45 to $130 per hour to fix wiring problems.

  • Structural repairs increase the cost.

• Air sealing an attic costs $350 to $3,000. Air sealing a whole house costs $1,000 to $5,000.

• Installing a roof vent costs $200 to $700. Any vents exhausting into the attic must be vented outside before installing new insulation.

• Encapsulating a crawl space costs $2 to $10 per square foot and includes insulation.

• Cleaning & hazard removal:

  • Attic cleaning costs $100 to $500 or more, depending on the condition.

  • Mold removal costs $15 to $30 per square foot.

  • Asbestos removal costs $10 to $25 per square foot. Asbestos testing costs $250 to $850.

  • A pest inspection costs $40 to $150 for the initial visit and is recommended before adding insulation.

• Soundproofing costs $10 to $30 per square foot or $760 to $2,400 per room, depending on the size.

• A home energy audit costs $100 to $700, depending on the utility type and home size.

• Weatherstripping costs $100 to $500.

Labor cost to install insulation

The labor cost to install insulation is $0.20 to $1.70 per square foot, depending on the insulation type and material, project size, and site conditions. Contractors charge $40 to $80+ per hour to install insulation.

Frequently asked home insulation questions

How much are bulk insulation prices?

Bulk insulation prices are 15% to 30% lower than retail prices. Hardware stores like Home Depot and Lowe's offer bulk pricing when purchasing 15 to 30+ bags or rolls of insulation.

What kind of insulation and R-value do I need?

The insulation type and R-value you need depend on your climate zone and the part of the home you are insulating.

What is the cheapest type of insulation?

Fiberglass batts and loose-fill fiberglass are the cheapest types of insulation to install. However, fiberglass requires replacement more often than other types, making it less cost-effective over time.

How long does insulation last?

Insulation lasts 20 to 100 years, depending on the type and site conditions.

• Fiberglass insulation lasts 80 to 100 years, but needs checking every 15 to 20 years to confirm the R-value is still up to code.

• Cellulose insulation lasts 20 to 30 years, but starts degrading after 15 years.

• Spray foam insulation lasts up to 80 years in most locations, or up to 30 years on the roof deck underside.

Is insulation worth it?

Insulation is worth it if your home is currently under-insulated. Adding insulation improves energy efficiency and may reduce utility costs by 10% to 40%, depending on the home's location, current insulation levels, and insulation type. Most older homes lack sufficient insulation.

Signs your home is under-insulated include:

• Increased utility bills

• Drafts

• Frequent temperature fluctuations

• Pest infestation

• Pipes freezing

• Some rooms are colder than others.

Who installs insulation?

Professional insulation contractors and some handyman services install insulation. Spray foam installation typically requires a trained, certified technician.

Installing insulation takes 2 hours to 2 days, depending on the project and crew size.

Getting home insulation estimates and quotes

Before hiring an insulation contractor or contractor:

• Get at least three insulation quotes to compare.

• Ask for a detailed quote including areas to be insulated, estimated R-value, insulation depth or thickness, and insulation brand and type.

• Read their reviews on HomeGuide and Google.

• Select insured and bonded companies that have been in business for 5+ years.

• Ask for references.

• Avoid selecting the lowest quote as quality may suffer.

• Get a detailed estimate, contract, and warranty in writing before the work begins.

• Never pay in full before the project starts. Use a payment plan instead for work completed.

Questions to ask insulation installers

• Are you licensed, bonded, and insured?

• How long have you been in business?

• What experience do you have installing insulation?

• Will the work be subcontracted?

• What insulation type do you recommend for my space, and why?

• Can I be inside the house during the installation?

• Does the quote include removing existing insulation?

• What is and is not included in the price?

• What additional costs should I expect?

• How long will the project take?

• How long should the insulation last?

• Is there a warranty? If so, what does it include?

• Do you offer financing options?

• Do you offer a whole-house discount?

• Are there rebates available, and do you apply for them?