How much does it cost to insulate a garage?
Ashburn, VA

How much does it cost to insulate a garage?

Ashburn, VA

How much does it cost to insulate a garage?

$0.50 – $3.00average cost per square foot
$800 – $5,100cost to insulate a 2-car garage (walls + ceiling)
$90 – $530cost to insulate existing 2-car garage door only
$1,500 – $3,700cost to install new insulated garage door

Get free estimates for your project or view our cost guide below:

$0.50 – $3.00 average cost per square foot

$800 – $5,100 cost to insulate a 2-car garage (walls + ceiling)

$90 – $530 cost to insulate existing 2-car garage door only

$1,500 – $3,700 cost to install new insulated garage door

Get free estimates for your project or view our cost guide below:
Tara Farmer
Written by
Tara Farmer
Edited by
Kristen Cramer
Fact-checked by
Tom Grupa

Average cost to insulate a garage

The cost to insulate a garage is $0.50 to $3.00 per square foot installed, depending on the size, height, and insulation type. Garage insulation costs $800 to $5,100 on average for the walls and ceiling in a 2-car garage. A 2-car garage door insulation kit costs $90 to $530. Installing a new 2-car insulated garage door costs $1,500 to $3,700.

Average cost to insulate a garage - chart
Average cost to insulate a garage - chart
Cost to insulate a garage
Garage size Walls only Walls & ceiling Walls, ceiling, & door
1-car garage (12x24) $350 – $2,000 $500 – $2,900 $600 – $3,200
2-car garage (24x24) $500 – $3,100 $800 – $5,100 $900 – $5,600
3-car garage (24x36) $600 – $3,600 $1,000 – $6,200 $1,100 – $7,100

*Average cost installed.

Cost to insulate an unfinished vs. finished garage

Insulating an unfinished 2-car garage costs $800 to $5,100 for the walls and ceiling, depending on the insulation type and R-value.

Insulating a finished garage requires more labor to either remove the drywall and replace it after installing the insulation or drill drywall holes and plug and patch them after spraying or blowing insulation.

Cost to insulate an unfinished vs. finished garage
Project type Cost to insulate 2-car garage (walls & ceiling)
Insulate an unfinished garage $800 – $5,100
Insulate and drywall an unfinished garage $1,800 – $9,000
Insulate a finished garage $1,600 – $12,800

*Total cost installed

Garage ceiling and walls insulated with spray foam
Garage ceiling and walls insulated with spray foam

Cost of insulating a garage ceiling

The cost to insulate a garage ceiling is $250 to $3,900, depending on the garage size, insulation type, R-value, whether the ceiling is finished. The most common garage ceiling insulation types are fiberglass batts and spray foam. Ceiling insulation is essential to prevent rising heat from escaping.

Cost to insulate a garage ceiling
Insulation type Average cost to insulate garage ceiling*
Batt and roll $250 – $2,200
Blown-in $300 – $2,400
Rigid foam $350 – $3,200
Spray foam $300 – $3,900
Reflective or radiant barrier $100 – $1,700

*Not including drywall.

Cost to insulate a garage door

A new 2-car insulated garage door costs $1,500 to $3,700+ installed, depending on the brand, style, and insulation type. The average cost to insulate an existing garage door is $100 to $800 for labor and materials.

Cost to insulate a garage door
Garage door size DIY kit cost to add insulation New insulated garage door cost installed
1-car garage $50 – $300 $750 – $1,900
2-car garage $90 – $530 $1,500 – $3,700+
3-car garage $130 – $890 $2,250 – $5,800+

  • Garage door insulation kits cost $50 to $200 each and include polystyrene foam panels, fiberglass batt rolls, or radiant barrier foil to retrofit an existing door. These kits are DIY-friendly but not as efficient as pre-insulated garage doors.

  • Insulating a garage door improves energy efficiency only when the door includes weatherstripping and the garage walls and ceiling are also insulated.

  • A radiant barrier reflects heat away but provides little to no R-value unless paired with another insulation.

Garage insulation cost per square foot by type

Garage insulation costs $0.80 to $4.50 per square foot, depending on the type. Batt and roll insulation is the cheapest and easiest to install in most cases. Spray foam and rigid foam insulation cost the most but provides a higher R-value per inch.

Garage insulation cost per square foot
Insulation type Cost per square foot installed* Average cost installed (2-car garage)*
Cavity batt and roll insulation cost $0.80 – $2.60 $1,500 – $5,300
Blown-in insulation cost $1.00 – $2.80 $1,400 – $4,600
Spray foam $1.00 – $4.50 $4,100 – $11,900
Reflective or radiant barrier installation cost $0.30 – $2.00 $500 – $3,200
Rigid foam board $1.20 – $3.70 $1,900 – $5,900

*Not including drywall installation. Average costs include walls and ceiling.

  • Radiant barrier insulation reflects heat away from the structure. Pair reflective insulation with another insulation type for best results.

  • Rigid foam lined with a radiant barrier works well when installing insulation without a finishing layer of drywall.

Cost of spray foam insulation in garage

The cost of spray foam insulation in a garage is $2,600 to $8,900 installed on average for the walls and $1,500 to $3,000 for the garage ceiling. Spray foam insulating the garage door costs $200 to $300 but using rigid foam and weatherstripping on the door is typically more effective.

  • Open-cell spray foam works well when installing drywall over the insulation.

  • Closed-cell foam is more rigid and durable, suitable for unfinished garage walls.

Cost breakdown of insulating a garage

The following factors affect the cost to insulate a garage:

Garage insulation installation cost breakdown
Factor Average cost per square foot
Remove old insulation* $1.00 – $2.00
Insulation material & supplies $0.20 – $1.30
Prep and installation labor $0.30 – $1.70
Total cost to replace $1.50 – $5.00

*Not required for new installations.

  • Size – The larger the garage, the more labor and materials needed to complete the job.

  • Attached vs. detached – An attached garage may already have insulation in the ceiling and on one or more walls, which reduces labor and materials.

  • Accessibility – Installing insulation in an empty garage costs less than installing it in a garage filled with items that require moving, covering, or working around.

  • Geographical location – Homes in cold regions typically require thicker insulation with a higher R-value, which increases costs.

  • Insulation type – Spray foam is the costliest insulation choice. Fiberglass batt and roll or blown-in insulation are the cheapest options.

  • Old insulation removal – Removing damaged or old insulation costs $1 to $2 per square foot, including disposal.

  • Weather stripping – Installing garage door weatherstripping costs $10 to $30+for the material alone and is essential for the most effective insulation.

  • Energy audit – An energy audit costs $100 to $700 to determine the air sealing level needed when insulating the garage.

  • Repairs – A handyman charges $50 to $80 per hour for home and garage repairs.

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

  • Pests – A pest inspection costs $40 to $150 and is recommended before installing insulation.

  • Noise – Soundproofing costs $10 to $30 per square foot.

R-value for garage insulation

The recommended R-value for garage insulation is R-6 to R-60, depending on the insulated area and the home's geographical location. The R-value for the garage ceiling also depends on if the garage opens to rafters or sits under a finished room. Install the highest possible R-value for best results.

Garage insulation R-value
Area Recommended R-value Insulation options
Garage ceiling / attic floor 30 – 60
  • Blown-in
  • Spray foam
  • Blanket / batt and roll
  • Reflective insulation
Garage door 6 – 14+
  • Rigid foam board
  • Fiberglass garage door kit
  • Radiant barrier or reflective insulationPolyurethane foam
Garage walls 13 – 15
  • Blanket / batt and roll (new/unfinished walls)
  • Rigid foam board(new/unfinished walls)
  • Blown-in (existing walls)Injection foam (existing walls)

Installing garage drywall

Installing garage drywall costs $800 to $5,000 and adds a layer of protection to garage insulation. Garage size, drywall thickness, and finish level affect the total cost.

  • Thicker, fire-rated, and moisture- resistant drywall is best for garages.

  • Local building codes often dictate the required drywall thickness.

Garage insulation FAQs

What is the cheapest way to insulate a garage?

The cheapest way to insulate an unfinished garage is with fiberglass batts or rolls for $0.80 ­to $2.60 per square foot installed. The batts and rolls fit between wall studs and ceiling joists, making them the most DIY-friendly choice. Blown-in insulation is often the cheapest insulation for a finished garage as it does not require total drywall removal.

What is the best insulation for a garage?

The best way to insulate a garage depends on your garage type, budget, geographical location, and goals. Fiberglass batts and rolls are the most common and budget-friendly, while spray foam is the most durable and airtight, making it an excellent choice when conditioning the space.

Garage insulation types and features
Insulation type Cost per square foot installed Features
Fiberglass batts and rolls $0.80 – $2.60
  • Best for an unfinished garage
  • Budget-friendly
  • Easy to install DIY
Blown-in cellulose or fiberglass $1.00 – $2.80
  • Best choice for a finished garage
  • Installs through small drywall holes or onto the garage ceiling or attic floor
Spray foam $1.00 – $4.50
  • Best for a conditioned garage
  • Expensive; requires professional installation
  • Mold, mildew, and pest resistant
  • Provides an air barrier and higher R-value per inch
Rigid foam $1.20 – $3.70
  • Best for thin walls and garage doors
  • Often includes a radiant barrier lining
  • High R-value per inch
Radiant barrier $0.30 – $2.00
  • Best paired with another insulation type
  • Ideal for warm climates; reflects heat away from home

Can you insulate a garage without drywall?

You can insulate a garage without drywall if the insulation is flame-tested and open-cavity installation complies with local building codes. Radiant-barrier-lined rigid foam or encapsulated fiberglass batts give the most finished uncovered appearance.

Most experts recommend installing drywall over insulation to reduce air leaks, add another moisture protective layer, and create the same aesthetic as the rest of the home.

How much insulation do I need for my garage?

Follow these steps to calculate how much insulation you need for your garage:

  1. Measure the garage's interior perimeter in linear feet.

  2. Multiply the perimeter by the wall height to get the wall square footage.

  3. Multiply the ceiling's length X width for the ceiling square footage.

  4. Add the wall + ceiling square footage for the total square footage.

  5. If using a separate door insulation kit, subtract the door square footage (door length x door width).

The amount of insulation needed also depends on the desired R-value. The recommended R-value is based on the insulated area and local climate:

  • Garage walls need an R-value of 13 to 15.

  • Garage ceilings need an R-value of 30 to 60.

  • Garage doors need an R-value of 6 to 14+.

Getting estimates from garage insulation contractors

Before hiring an insulation contractor to insulate your garage:

  • Get at least three quotes to compare.

  • Get quotes during the insulation contractors' down season, typically late fall and early winter.

  • Browse their reviews on HomeGuide and Google.

  • Select only insured and bonded companies that have been in business more than five years.

  • Request a detailed estimate including areas to be insulated, estimated R-value, insulation depth or thickness, and the insulation brand and type.

  • Ask for references with contact information.

  • Avoid selecting the lowest bid as quality may suffer.

  • Get an itemized estimate, contract, and warranty in writing before the work begins.

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

Questions to ask insulation installers

  • Are you licensed, bonded, and insured?

  • How long have you been in business?

  • What experience do you have insulating garages?

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

  • Does the estimate include removing damaged or old insulation?

  • What additional costs should I expect?

  • How long will the installation take?

  • How long should the insulation last?

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

  • Do you offer financing?

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