Digging out a basement typically costs between $50,000 and $150,000 or more, making it one of the most complex home improvement projects you can take on. The final price depends on factors like the size of the space, your home’s structure, and site conditions.
Unlike standard renovations, this project involves excavating beneath your home and reinforcing the existing foundation. The process can take several months and may require temporarily relocating during construction. We’ll break down typical costs, key pricing factors, and how to decide whether a basement dig-out makes sense for your home.
Key Takeaways
- Digging out a basement costs $60,000–$150,000, while converting a crawl space ranges from $47,500–$135,000, depending on the scope and structural complexity.
- Excavation alone costs $75–$150 per cubic yard, with a 1,000-square-foot basement requiring about 300 cubic yards, or $22,500–$45,000 in excavation costs.
- Major cost drivers include raising or bracing the home, a new foundation, plumbing, and permits.
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Differences Between Basement Excavation and Crawl Space Conversion
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Digging out a new basement and converting a crawl space both add usable space, but they differ in cost, complexity, and disruption.
Excavating a basement involves removing large amounts of soil beneath your home and building a new foundation. The digging alone can cost $22,500–$45,000, with total project costs reaching up to $150,000 depending on the scope of work . This approach is more labor-intensive and is often required for homes built on slabs or when you want maximum ceiling height.
Crawl space conversion starts with an existing shallow foundation, so less digging is required. Excavation costs typically range from $10,000–$30,000, while total project costs fall between $47,500 and $135,000. However, you’ll still need to account for structural work such as underpinning, along with plumbing and a new foundation system.
The right option depends on your home and site conditions. Crawl space conversion is often more practical when there’s enough existing height to expand downward, while full excavation may be necessary for larger or more complex projects. Limited access, poor soil, or structural issues can also increase costs, especially when contractors must remove soil in smaller loads or work in tight spaces.
Note: The cost figures featured throughout this guide are based on estimates from Angi and HomeAdvisor, unless otherwise noted.
What Factors Affect the Cost Of Digging Out a Basement?
Several factors influence the total cost of excavating a basement, and many depend on the specific conditions of your home and property. While basic estimates provide a general range, real project costs often vary based on structural complexity, site access, and the amount of excavation required.
- Size of excavation: The larger the space you need to have excavated, the more the project will cost.
- Raising or bracing: Raising your home on jacks will be less expensive but also less stable than bracing it.
- Plumbing: Your new basement will need proper plumbing and drainage systems.
- Permits: Local building codes will determine how much you’ll pay in permit costs.
- Foundation: A new concrete foundation will need to be poured under your new basement.
Size of Excavation
The size of the space is one of the biggest cost drivers, since excavation is typically priced by volume. Homeowners can expect to pay $75–$150 per cubic yard of dirt removed, with a 1,000-square-foot basement requiring roughly 300 cubic yards, or $22,500–$45,000 for digging alone. Larger or deeper basements increase both labor time and hauling costs, especially if soil must be removed in multiple loads.
Raising or Bracing the Home
Your home must be supported while excavation takes place beneath it. Raising the house on hydraulic jacks is generally faster and less expensive, typically costing $3,100–$9,400, but it can place more stress on the structure. Underpinning, which involves reinforcing the foundation in sections, is more stable but labor-intensive and can cost up to $20,000. The right method depends on your home’s condition and structural requirements.
Soil Conditions and Site Access
Soil type and accessibility can significantly impact both cost and timeline. Loose, sandy soil is easier to excavate, while dense soil, rock, or bedrock may require specialized equipment or additional labor. Limited access around the home can also slow the process, as contractors may need to remove soil in smaller loads rather than using large equipment or staging areas.
Plumbing and Water Control
To make your new basement space livable, you’ll need to install new plumbing. In addition, you’ll need drainage and waterproofing to keep your basement dry if you live in an area with a high water table. Plumbing installation typically costs $1,000–$3,000, while drainage systems can range from $2,000–$6,000, depending on soil conditions and water table levels. Homes in areas with high groundwater may require more extensive waterproofing solutions.
Engineering and Structural Design
Because this project involves altering your home’s foundation, a structural engineer is essential. Engineering costs usually run in the thousands but are critical for ensuring the safety and stability of the structure. Design requirements can vary widely depending on soil conditions, load-bearing needs, and the chosen excavation method.
Permits
Permit requirements vary by location, but most projects cost between $1,200 and $2,000. These costs may increase in areas with stricter building codes or additional inspections.
New Foundation
Once the engineering is completed, the permit is obtained, and a contract has been signed, your home will need a new foundation. The price of a foundation for footings, walls, and the cost of pouring a concrete slab is usually between $10,000 and $30,000.
Additional Cost Considerations for Digging Out a Basement
In addition to major construction costs, several secondary factors can increase the total price of a basement dig-out.
If you’re planning a home addition, it’s often more cost-effective to include a basement during new construction rather than excavating beneath an existing structure. Aboveground additions typically cost $21,000–$73,000, making them a simpler, more affordable alternative in many cases.
You can use an unfinished basement for storage space, but if you want it to qualify as extra living space, you’ll need to finish the basement. The cost to finish a basementis usually between $7 and $23 per square foot and may include flooring, HVAC additions, plumbing, electrical, drywall, painting, and egress window installation.
Adding a walkout basement or exterior access can increase both usability and cost. Installing a walkout door in an existing basement may cost $2,500–$10,000, while incorporating one into a full excavation project can push costs toward the higher end of the overall price range.
Excavation can expose underlying issues with your home’s foundation. Contractors may uncover cracks, uneven settling, or missing structural elements that require repair before work can continue. Foundation repairs can cost $2,100–$7,800, while structural damage from raising the home may add to these costs. In some cases, these issues aren’t discovered until excavation is already underway.
Excavation often disrupts surrounding landscaping, including trees, grading, and drainage. Restoring your yard after construction may require additional work, especially if heavy equipment has compacted soil or altered the slope of your property.
Adding a basement may increase your home’s insured value and, in turn, your homeowners insurance premiums. You may also need to update coverage during construction to account for potential risks associated with excavation work.
DIY vs. Professional Basement Excavation
Digging out a basement beneath an existing home is not a typical DIY project. This type of work involves structural changes to your home’s foundation, specialized equipment, and precise engineering to prevent damage during excavation.
DIY Basement Excavation
While minor excavation projects may be manageable for experienced homeowners, digging out a basement requires advanced knowledge of structural support, soil conditions, and load-bearing systems. Even small miscalculations can destabilize the foundation or cause uneven settling.
For example, excavation must be done carefully to avoid disturbing the soil that supports your home. Contractors often finish critical areas by hand to reach stable, undisturbed soil, since heavy equipment can loosen the base and increase the risk of shifting or failure.
Professional Basement Excavation
Professional contractors use engineered plans and specialized techniques to safely support your home during excavation. This may include raising the structure or reinforcing the foundation in sections, depending on the method used.
They also account for site-specific challenges, such as soil type, drainage, and access limitations, which can affect both safety and cost. Because unexpected conditions are common, such as missing footings or unstable soil, contractors must be able to adapt the project as work progresses.
In most cases, hiring a professional is the only practical and safe option. The risks of structural damage, water intrusion, or project failure are high without the proper expertise, and mistakes can be costly to repair.
Is It Worth Digging Out a Basement?
Digging out a basement is a major investment, and whether it’s worth it depends on your home, budget, and long-term plans. While the added space can improve functionality and value, the cost and complexity are significantly higher than most other home improvement projects.
This type of project often makes the most sense when expanding outward or upward isn’t an option. Homes on small lots, in dense urban areas, or with zoning restrictions may benefit the most from adding space below ground.
However, excavation is disruptive and can take several months to complete, and the home may be partially or fully uninhabitable during construction. Costs can also increase as work progresses, especially if contractors encounter structural issues or poor soil conditions.
For many homeowners, building an addition or renovating existing space is more practical and cost-effective. Digging out a basement is typically best suited for long-term homeowners who need additional space and are prepared for the time, cost, and complexity involved.
FAQs About the Cost Of Digging Out a Basement
How do you excavate a basement under an existing house?
Contractors excavate a basement by first supporting the house by either raising it on jacks or underpinning it. Then, they use heavy machinery such as a backhoe or Bobcat to excavate the space. They then pour concrete walls and a concrete floor to serve as the new foundation.
What is the deepest you can dig a basement?
According to U.S. residential building codes, you can only dig a basement that’s one floor deep. Usually, that equates to a ceiling height of about 8–10 feet.
Can you dig a basement next to an existing house?
You can dig a basement alongside an existing house, but only under certain conditions. The soil needs to be the right consistency and free of bedrock, and your home needs to be structurally sound since the current foundation will be undermined when you dig next to it.
Can you turn a crawl space into a full basement?
Yes, a crawl space can be converted into a full basement. The process is similar to the situation described above but generally requires slightly less excavating as some space is already free of soil.
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