How Much Does It Cost To Convert A Crawl Space Into A Basement?

Typical Range:

$60,000 - $150,000

Find out how much your project will cost.

Cost data is based on research by HomeAdvisor.

Updated July 7, 2022

Written by HomeAdvisor.

Convert Crawl Space to Basement Cost

Converting a crawlspace to a completely finished basement costs $50 per square foot on average with a typical range of $30 to $75 per square foot. Adding 2,000 square feet under your home runs $60,000 to $150,000. Expanding an existing partial basement into a full one might run $20,000 to $70,000.

It’s almost always cheaper to build an addition. But if you don’t have the room to add on, you’ll need to know what it takes to add a basement.

Average Cost to Convert a Crawl Space Per Square Foot

Average Cost High Cost Low Cost
$50 $75 $30

Cost to Dig Out Crawl Space

Costs for crawl space to basement conversion range $30 to $75 per square foot

The cost of digging a basement under a crawl space will range between $10,000 and $30,000 in most cases. This includes raising or bracing the home and digging out the actual dirt and rock. You’ll do this in two steps:

  1. Raise or brace your home

  2. Dig out the dirt and rock

Remember that this area usually has an unfinished floor, meaning there’s no slab or concrete to go through, so the digging is fairly easy, the real problem comes down to access. Although uncommon, it’s possible you might have poured concrete under your home, which might adds a little time and maybe $500 to $1,500 to remove.

Cost to Raise or Brace a Home

You’ll spend somewhere between $3,100 to $20,000 or more to raise or brace the home. Some contractors opt to jack it up while others prefer to simply dig and brace each footing individually as part of the process.

  • Raising a home costs $3,100-$9,400. Your general contractor will hire a specialized professional for this.

  • Bracing the foundation footings come as part of the digging process but adds up to $20,000 to the cost. This simply adds more labor time to the project. While it adds more to the bill, it keeps your home from moving, meaning less damage to interior walls, ceilings and floors.

Crawl Space Excavation Costs for a Basement

For a 1,000 square foot crawlspace, you’re looking at $30,000 to $45,000 just to excavate space for a basement. It’ll cost $75 to $150 per cubic yard to excavate under your home.

Every 1,000 square feet of home has approximately 300 cubic yards of dirt to remove. It’s a slow process since most of the work gets done manually, without large machinery.

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Cost to Convert Crawl Space Into Full Basement

Converting a crawl space into a full basement costs $50,000 to $150,000. Done right, it’s quick, but still takes a few distinct steps. For an unfinished basement, you’ll need to first dig out the crawlspace, discussed above. Once that’s done, you’ll need to:

  • Install drainage and plumbing.

  • Place the forms and pour the foundation.

  • You can then opt to finish the space for living or leave it unfinished for storage and utility use.

Installing Drainage and Plumbing

Installing drainage, plumbing and sewer lines under a new foundation runs $3,000 to $9,000. But it’s broken up between the two. Look for the following rates as line items on your bill:

Cost to Pour a Foundation

Pouring a foundation costs $10,000 to $30,000 on average. This includes the footings, floor and walls. Once the space is empty with drainage and plumbing placed, it’s a simple process. Your pros will set up forms and pour the foundation like any other.

Adding a Finished Basement

Once dug out, you can turn the area into a fully functioning basement. A full basement remodel costs another $12,250 to $33,250 depending on the size of the project and your desired finishings.

Finishing a basement costs $7 to $23 per square foot. Individual costs vary for the following parts of a completed space:

Is Digging Out a Crawl Space a Good Idea?

Generally, digging out a crawl space isn’t a great idea. It’s risky and costly with other easier and cheaper options available. Ask yourself a couple questions:

  • What’s the ROI? Contact a local Realtor or appraiser to find out if it makes sense for your neighborhood and the costs involved.

  • Do you want to pay for damages and landscaping? Jacking it up causes drywall to crack and might cause other issues with plumbing and electrical. Plus, you’ll probably need to worry about landscaping after its all done.

  • Addition vs. Digging. Do you have room to add an addition rather than dig out under your home? It’s almost universally cheaper to add on.

Basement vs. Addition Costs

If you have the room, it’s more cost effective to build an addition with a basement under it. Consider the prices:

DIY vs. Hire a Professional

Never try to do this DIY. It’s a complicated process that can cause catastrophic damage to your home when done improperly. Whether you choose to shore up the footings while digging or jack the home up, any mistake might mean irreparable damage.

Call a foundation installation professional near you to get quotes and answer specific questions about your project.


How much does it cost to finish a crawl space?

Encapsulating a crawl space costs $1,500 to $15,000 depending on both the size and type of process used.

Can you make a basement deeper?

You can make a basement deeper. Excavating out a basement runs $50,000 to $90,000 on average, a bit cheaper than digging out a crawlspace, but not by much. The process is almost identical.

Can you add a basement to an existing house?

You can add a basement to an existing house for $20,000 to $150,000. A typical scenario you’ll run into is a home with a partial basement and a small crawlspace. You can expect to spend around $50,000 for partial installs.

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