InstaBidsHow much does crawl space insulation cost?
This survey has no crawl space insulation-specific figure. The figure below covers all "Added or replaced insulation" jobs, so read it as context, not as the price of crawl space insulation alone.
Context: all "Added or replaced insulation" jobs
$2,500 was the median homeowner survey figure for data years 2021-2023 in the United States. All jobs in “Added or replaced insulation”, including work beyond crawl spaces, had a typical range (middle half of 372 American Housing Survey data points, the United States, 2021-2023) of $1,000 to $5,000.
Updated 2026-11-02
InstaBids is an AI-run marketplace for homeowners and property managers: describe a home job once, by chat or through your own AI assistant, add photos, and get multiple written quotes on the same scope, compared apples to apples, with no phone calls or home visits before you pick.
For homeowners, property managers, landlords and HOA boards.
| What was measured | Median | Typical range (middle half) |
|---|---|---|
| All jobs in “Added or replaced insulation”, including work beyond crawl spaces, had | a median of $2,500 | the typical range (middle half of 372 American Housing Survey data points, the United States, 2021-2023) was $1,000 to $5,000 |
How measured: hired-out finished jobs, survey-weighted, not adjusted for inflation. Source: U.S. Census Bureau, American Housing Survey 2023, data read 2 November 2026.
These figures are estimates from U.S. Census Bureau, American Housing Survey 2023, data years 2021-2023, read 2 November 2026, for the United States. They are not a quote, and they are not a promise of what any contractor on InstaBids will charge. Your price depends on your home, the materials and the contractor. Get written bids before you decide.
- Describe it onceBy chat, or through your own AI assistant, and add photos.
- Post it and send itContractors bid in writing on that scope.
- Compare line by lineEvery quote is written against the same scope.
- You chooseContact details stay hidden until you pick and they confirm.
For your AI assistant
MCP connector · REST API · plain HTMLHand any of these to your assistant and it can help you write this job's request; you send the request yourself. What you type in the job box above goes into the prompt these buttons carry. The connector asks you to sign in to your InstaBids account the first time.
- MCP connector URL
https://instabids.ai/api/agent/mcp - Agent API (OpenAPI)
https://instabids.ai/openapi.json - Start-request link
https://instabids.ai/intake?from=cost-wall-crawlspace-insulation&utm_source=us&utm_medium=page&utm_campaign=cost&page_type=cost&job=wall+crawlspace+insulation - Prompt for any AI, with your job
- ChatGPTOpens with the prompt
- ClaudeOpens with the prompt
- GrokOpens with the prompt
- GeminiCopies the prompt, then opens
Every page is plain HTML. Steps for every assistant: add to your assistant.
What is the crawl space insulation cost?
U.S. Census Bureau, JOBTYPE 20: “Added or replaced insulation”
Source: U.S. Census Bureau, AHS 2023 Value Labels Package, read 2 November 2026.
DOE, single-family and multi-family retrofit: “When looking for opportunities to improve the energy efficiency of older single-family and multi-family residential buildings, sealing and insulating of vented crawlspaces is one retrofit measure that can improve the energy efficiency, comfort, and durability of the structure, particularly in climates with cold winters and/or hot humid summers.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
On InstaBids, describe whether your crawl space job concerns the foundation walls or the floor above before contractors write their bids.
How much is crawl space insulation?
DOE, floor insulation options: “Floors above unconditioned basements and crawlspaces can be insulated to high levels using batt or spray foam insulation, or a combination.”
Source: U.S. Department of Energy, Building Science Education, read 2 November 2026.
DOE, batt fit: “Batt insulation should be installed so that it fits tightly between the floor joists with no gaps, compressions, or voids.”
Source: U.S. Department of Energy, Building Science Education, read 2 November 2026.
For a floor insulation job on InstaBids, describe the joists and the insulation you want contractors to bid on in writing.
What is the cost for crawl space insulation?
DOE, water management before retrofit: “Treat bulk water drainage issues and provide additional moisture control measures as needed to address site moisture issues before retrofitting a vented crawlspace to an unvented, insulated crawlspace.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
Include crawl space drainage preparation in your InstaBids description so contractors answer the same written scope.
What is the insulation for crawl space cost?
DOE, ground vapor barrier: “Install a vapor barrier of 6-mil or thicker polyethylene sheeting that completely covers the crawlspace floor and extends up the foundation walls and any piers by 8 to 12 inches, or preferably up to the exterior ground level.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
On InstaBids, put the ground liner and its wall connections in the description that contractors bid on.
What is the crawl space spray foam insulation cost?
DOE, foam air-barrier thickness: “To qualify as an air barrier, open-cell or closed-cell foam must have a finished thickness greater than or equal to 5.5 inches or 1.5 inches, respectively.”
Source: U.S. Department of Energy, Building Science Education, read 2 November 2026.
Specify the foam type and intended thickness in your InstaBids job so the written bids address those details.
What is the cost of crawl space insulation?
DOE, pest inspection space: “Allow space for a pest control inspection strip above the foam sheets and below the rim joist, if required by local jurisdictions.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
On InstaBids, include the pest inspection gap in the crawl space scope that each contractor receives.
What crawl space insulation includes
Where a quote below names a city or county, it is that office's own rule, shown as one example; the permit office for your home may set different rules.
| What the source says | Where it comes from |
|---|---|
| DOE, wall insulation approach: “Construct an unvented crawlspace and insulate the interior walls with rigid foam insulation; this can provide an insulated, air-sealed environment for ducts and HVAC equipment, protect floor joists from condensation from humid air in humid climates, and protect floors and pipes from cold temperatures in cold climates.” | U.S. Department of Energy, Building America Solution Center, read 2 November 2026. |
| DOE, conditions to address first: “If any standing water, mold, rotten wood, or hazardous materials are present in the crawlspace, these conditions should be addressed before air sealing and insulating the crawlspace.” | U.S. Department of Energy, Building America Solution Center, read 2 November 2026. |
On InstaBids, include the condition of the crawl space walls and framing in the job description contractors bid on.
Line items a written bid should list
- DOE, liner and rigid foam sequence: “Cover the walls and floor of the crawlspace with a polyethylene vapor retarder prior to installing the rigid foam.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
- DOE, vent openings: “If the crawlspace has vents, install pieces of rigid foam cut to fit in the vent openings and seal in place with spray foam or caulk.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
- DOE, access doors: “Insulate access doors and provide air sealing with gaskets or weather stripping.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
- DOE, subfloor penetrations: “Before insulating, any holes around plumbing wiring, etc. in the subfloor must be sealed.”
Source: U.S. Department of Energy, Building Science Education, read 2 November 2026.
On InstaBids, list the liner, vents, doors and penetrations as separate items in your crawl space scope.
How to compare written bids like for like
Ask every contractor to bid in writing on the same line items listed above, then compare the written bids line by line.
DOE code compliance brief, documented wall scope: “The type, amount, and location of the insulation in the wall assemblies must be shown as well as how any openings (e.g., access doors) in insulated walls are to be sealed and insulated.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
DOE, liner after installation: “When the installation of insulation on the crawlspace walls and band joist is complete, inspect the vapor retarder on the floor of the crawlspace. If any tears or rips in the vapor retarder occurred during the work, repair and seal the tears.”
Source: U.S. Department of Energy, Building America Solution Center, read 2 November 2026.
Read the written crawl space bids on InstaBids against your wall insulation and liner repair scope before choosing who gets your number.
Get written bids
Contractors who take part bid on one written scope card, so nobody visits before you see any prices.
Sources for the figures on this page
- U.S. Census Bureau, American Housing Survey 2023, https://www.census.gov/programs-surveys/ahs/data/2023/ahs-2023-public-use-file--puf-.html, read 2 November 2026. U.S. government work; no endorsement implied.
- U.S. Census Bureau, AHS 2023 Value Labels Package, www2.census.gov/programs-surveys/ahs/2023/AHS 2023 Value Labels Package.zip, read 2 November 2026.
- U.S. Department of Energy, Building America Solution Center, basc.pnnl.gov/resource-guides/water-management-existing-crawlspace-floor, read 2 November 2026.
- U.S. Department of Energy, Building Science Education, bsesc.energy.gov/energy-basics/insulating-floors-over-unconditioned-space, read 2 November 2026.
- U.S. Department of Energy, Building America Solution Center, basc.pnnl.gov/resource-guides/unvented-insulated-crawlspaces, read 2 November 2026.
- U.S. Department of Energy, Building America Solution Center, basc.pnnl.gov/code-compliance/sealing-and-insulating-existing-crawl-space-walls-code-compliance-brief, read 2 November 2026.