Cost of excavating a basement under an existing house

Lowering an existing basement floor 1 to 2 feet costs about $40,000 to $90,000.¹ Digging a full basement under a house that sits on a crawl space runs $48,000 to $200,000.¹ The spread comes down to three things: how the house is held up while the dirt comes out, how much soil leaves the site and how wet the ground is. Excavation prices for new homes look far lower because no house sits on top.¹

TL;DR

• Budget $40,000 to $90,000 to lower an existing floor and $48,000 to $200,000 to turn a crawl space into a full basement.¹ The top of the crawl space range includes finishing.¹
• The support method sets a big share of the price. Jacking the house is cheapest but can crack drywall. Underpinning adds up to $20,000.¹ A bench footing leaves a concrete ledge around the walls.
• Soil is the bill people miss. Expect about 300 cubic yards per 1,000 square feet, at $75 to $150 a yard when the dig happens under a house.¹
• A dig-out pays off when you finish the new space and use it for years. Published returns on a basement finish run 64% to 75%.²³ Both are below 100%, so resale alone won't repay the finish, let alone the dig.
• The engineer, the permit, drainage and waterproofing are fixed parts of the job. Get each one as its own line on the quote.

How much does it cost to dig out a basement under an existing house?

Digging out a basement costs $24,000 to $50,000 for a typical project, based on Angi's 2026 cost guide.¹ The average is $37,000, and hard jobs reach $150,000.¹ The type of job moves the price most. Deepening an existing basement and converting a crawl space both start near or above the top of that typical range.¹

Angi prices each job type separately.

Partial-to-full expansions cost less because a partial basement should already have electricity, drainage, plumbing and gas.¹ Location matters too. Angi's city averages for a dig-out run from $54,200 in San Antonio to $83,900 in San Jose.¹ Angi publishes no dig-out figures for Georgia or Colorado cities, so get a site visit for a local number.

Why do forum and excavator prices look so much lower?

Forum threads and excavation calculators mostly price a hole on an open lot. That job has no house to hold up. Angi puts a new-construction basement dig at $10,000 to $30,000 because it takes less labor.¹ Under an existing house, Angi puts soil removal at $75 to $150 per cubic yard.¹

The gap comes from access. On an open lot, a full-size excavator digs the hole and trucks pull up beside it. Under a house, the crew works around the old footings in a tight space. Every yard of soil leaves through a narrow opening.

Angi says homes where heavy equipment is hard to get in and out may cost more.¹ Time shows the same gap. A new-construction dig takes around three days in Angi's figures, while most dig-outs under an existing home take at least two to five weeks.¹

Use a new-build number from a thread as the floor for one line of your quote. It is never the price of the whole job.

Underpinning or bench footing: which support method fits your house?

Underpinning extends the existing footings down to the new floor depth, so you keep the whole floor. A bench footing leaves the old footing in place and pours a concrete ledge around the inside of the walls. It needs less digging under the footings but costs floor space. Your structural engineer picks the method from the soil and the footings.

Some jobs lift the house first, then dig underneath. The two guides that price these methods disagree, partly because they describe different amounts of work.

Lifting the house

Hydraulic jacking is the cheapest way to raise the house. Angi warns it can crack drywall and damage floors and ceilings.¹ For a lift on its own, budget from HomeGuide's $10,000 to $40,000.³ Angi's lower figure is its average for jacking alone.¹

Underpinning

Underpinning braces the footings one at a time, then raises the structure gradually. That limits damage to floors, walls and ceilings.¹ The extra labor is why Angi says it can add up to $20,000.¹

Bench footing

Benching pours a concrete ledge around the existing walls and leaves the footings where they are. The ledge takes floor width along every wall, which hurts most in a small basement. Neither cost guide prices benching on its own. Ask your engineer to show both options on the drawings with the cost and usable floor area of each.

What does it cost to haul the dirt away?

Plan on about 300 cubic yards of soil for every 1,000 square feet of new basement.¹ At $75 to $150 per cubic yard, Angi puts that dig at $22,500 to $45,000.¹ Breaking out an existing concrete floor adds $500 to $1,500.¹

Spoil is the dirt that comes out, and it has to go somewhere. Haul distance, dump fees and any contamination in the soil all move that bill. Clean fill can sometimes stay on your lot for grading. Ask whether your quote assumes you keep any of it.

Rock changes the math fast, because it may need breaking or blasting. Put a clause in the contract that says how unexpected rock gets priced.

Scale it to your footprint. By our arithmetic, a 2,000-square-foot basement is about 600 cubic yards at the same ratio, which works out to about $45,000 to $90,000 for the dirt at Angi's per-yard rate. Angi's per-square-foot table runs higher for the same size, at $60,000 to $150,000.¹ Budget from the higher figure.

What do drainage and waterproofing add?

A new basement needs expanded drainage and waterproofing before anything gets finished.¹ Angi puts expanded drainage at $2,000 to $5,500, waterproofing at $2,300 to $7,600 and under-slab plumbing at $1,000 to $3,000.¹ If you want the full menu of options, see what basement waterproofing costs.

The cheapest time to waterproof is while the soil is already dug out. Angi says adding it then can save thousands later.¹

A high water table adds its own line. Angi says a deeper basement may need a water management system, depending on the water table.¹ It also says hard clay soil is harder to dig and may need extra steps to drain properly.¹ HomeGuide prices a sump pump at $600 to $2,500 installed.³ It puts a drainage system at $10 to $25 per linear foot, or $1,000 to $4,000 total.³

On a dry site, Angi's drainage and waterproofing ranges are a fair starting point. On wet ground or heavy clay, add HomeGuide's sump pump and drainage figures on top.

What does the engineering and permit path look like?

The permit path runs in five steps: site and soil check, structural design, permit, utility locate, then inspected construction. Structural permits for a dig-out run about $1,200 to $2,000.¹ A structural engineer bills $100 to $220 an hour.³

Rules and fees vary by city and county. Your building department has the final say on what it needs.

1. Check the site and the soil

Get the soil checked before the job is designed. Soil sets both the price and the method. Angi says the soil type and the existing foundation can make a dig-out a poor idea.¹ Look at your street too. Angi's point is plain: if most homes nearby have no basement, there could be a reason.¹

2. Get a structural design

The engineer decides how the house is supported and how deep you can go. Angi notes a structural engineer can tell you the maximum depth that works.¹ The design also sets the footing, wall and floor details your permit drawings need.

3. Pull the permit

Lifting a house and digging below it will almost certainly need building permits, and Angi expects them to cost more than standard permits.¹ Angi also suggests confirming the permit requirements with your contractor and whether they handle the process.¹ Finishing the new space later brings its own permit, covered in our guide to basement finishing permits.

4. Call 811 before anyone digs

Call 811 before any digging starts so the buried utility lines get marked. Lines in the way cost money to move, so ask for that as its own line on the quote.

5. Build, inspect and insure

Check your homeowner's insurance before work starts. Angi suggests confirming your policy covers $100,000 to $200,000 of repairs, and your premium may rise.¹ If you plan to finish the space, plan for the rules that come with it. HomeGuide says basement bedrooms and living spaces need an egress window or door, at $2,000 to $5,000 installed.³ It also lists a 7-foot minimum ceiling.³ An egress window is an opening large enough to climb out of in a fire. Local adoption of the building code varies, so confirm the exact sizes and heights your city or county requires.

How much does it cost to dig a 2,000 sq ft basement?

Excavating a 2,000-square-foot basement costs $60,000 to $150,000 for the dig alone, based on Angi's $30 to $75 per square foot.¹ By our arithmetic, adding Angi's foundation, drainage, waterproofing and permit ranges brings the unfinished shell to about $75,500 to $195,100 before the house is lifted or underpinned.

Angi's excavation figures by size:

Here is a full planning stack for 2,000 square feet. Each line comes from a published range. The subtotal and total rows are our own arithmetic.

Treat the fixed lines as low for a basement this big. Angi gives its foundation, drainage and permit figures as flat ranges, with no scaling by size.¹

Finishing is where the guides split widest. Angi's rate of $7 to $23 per square foot gives $14,000 to $46,000 for 2,000 square feet.² HomeGuide puts an open-plan finish at that size at $60,000 to $80,000, and a three-room layout at $80,000 to $100,000.³ Budget from HomeGuide. It is the more conservative of the two, and most people who dig out a basement want rooms in it. Our basement finishing cost guide breaks the finish down line by line. When you reach that stage, basement finishing is the next job to price.

Local finish prices differ too. Published finish ranges, checked September 2026, are $45,000 to $80,000 for a typical full finish in metro Atlanta and $30,000 to $90,000 in metro Denver. See what finishing costs in Atlanta or what finishing costs in Denver.

Is it worth it to dig out a basement?

Basement Remodeling Co.'s view is that a dig-out is worth it when you will finish the new space and use it for years. Angi puts the return on a basement finish at 64% to 70%, and HomeGuide puts it at 70% to 75%.²³ Both are below 100%, so resale alone won't repay the bill. Angi adds that deepening without new finished square footage returns little.¹

Those return figures describe finishing a basement that already exists. None of the cost guides publish a resale return for the digging itself. Angi's example shows the scale: spend $10,000 on a finish and your home value could rise by $6,400 to $7,000.² The dig-out sits underneath that spend and adds no finished space until the finish goes in.

The math tends to work when three things are true:

• You need the space and plan to stay. Angi says a dig-out can still make sense in an existing home if you would benefit a lot from the extra square footage.¹
• Comparable homes nearby have basements. Angi suggests checking sale prices of comparable homes in your neighborhood first.¹
• The ground suits it. Angi warns a dig-out may not be worth it on a slab foundation or in soil that doesn't suit basements.¹

Once the house is braced, adding floor area can help the return. Angi's advice is to dig out a full basement at that point for a better ROI.¹ If you only want a dry crawl space, encapsulation is the cheaper path, at about $5,500 on average.¹

How hard is it to dig a basement under an existing house?

It is a major structural job. The crew supports the whole house and digs beneath it, and the house will likely be uninhabitable while work runs.¹ Angi says there are no circumstances where a homeowner should attempt the dig themselves.¹ Most projects take at least two to five weeks, and obstacles can stretch that to several months.¹ Bracing or raising the house first adds time.¹

Depth adds difficulty. Most residential basements are 8 to 10 feet deep.¹ Going deeper needs stronger walls and more support. A high water table may also call for a water management system.¹ Clay can support a deeper foundation than sandy soil.¹

Weather adds more. Frozen or waterlogged ground slows the work and adds labor. Set aside a contingency for surprises such as rock or a high water table.

What should a dig-out quote show?

A good dig-out quote splits the job into lines you can compare: support method, soil volume, haul-off, drainage, waterproofing, foundation, permits and a written plan for rock and water. Get several written estimates that each show the scope, timeline, materials, payment schedule and a plan for rock or water. Compare them line by line.

Check each quote for these:

• The support method by name, and who designed it.
• The soil volume and the number of truckloads.
• Hauling and disposal fees as their own line.
• A plan and a price for rock or water.
• Temporary shoring or bracing listed as a material.
• Permit fees and who pulls the permit.
• Any general contractor markup. Angi says hiring a general contractor adds 10% to 20%.¹

The dig itself belongs to a foundation or excavation contractor working from your engineer's design. Once the new space is dry and inspected, the finishing work starts. Basement Remodeling Co. sends your request to one vetted, licensed basement contractor for your metro. That contractor gives you a free on-site estimate and a written, itemized quote. When you're ready, you can get a written quote for your basement remodel or find a basement contractor by ZIP code. In Colorado, see finishing costs in Colorado Springs and finishing costs in Fort Collins.