How Much Does It Cost to Dig Out a Basement?

Highlights

• Most homeowners will spend between $60,000 and $150,000 on basement excavation costs.
• The cost to dig out a basement depends on the size and layout of the basement, the need for house bracing or raising, drainage and plumbing, excavation, permits, labor costs, foundation repair, and more.
• Expanding or deepening a crawl space or small basement can offer homeowners more living space and an increased home value,
• Excavating a basement under an existing home requires the expertise of structural engineers and qualified contractors who understand how to protect the integrity of the home’s structure while expanding the home’s footprint.

Any added living space to a home is a great way to increase the property value whether it’s an extra bathroom, bedroom, second kitchen, home office, or even just storage space. One of the most impactful ways to expand usable home space is by adding a basement to an existing house. A new basement gives the home’s occupants an entire extra floor to utilize with multiple room configurations.

If the home already has a small basement or crawl space, contractors can deepen, expand, or dig out the area and convert it into a full basement. The cost to dig out a basement runs from $60,000 to $150,000 on average, according to Angi and HomeAdvisor. This estimate applies to a 2,000-square-foot basement that’s converted from a crawl space. Naturally, the total cost of a basement project can fluctuate based on the size of the space, drainage and plumbing requirements, the type of excavation project, and more. Local contractors can help homeowners calculate the most accurate estimate beyond the most common costs that projects typically incur.

Factors in Calculating the Cost to Dig Out a Basement

Increasing the size of the home is beneficial for both the current and future owners, but before starting a basement excavation project, homeowners can learn more about the aspects of the project that can affect the cost to dig out a basement. Such aspects include the average basement size, excavation rate per hour, drainage and plumbing costs, as well as any permit requirements and additional costs involved with bracing or raising the home.

Basement Size and Layout

A key factor for homeowners to calculate when drawing up a budget for a basement excavation project is the intended size and layout of the basement. Larger basements will always end up on the higher cost range. Similarly, if the homeowner wants a basement with a higher ceiling or a complex layout, then the project may take longer to complete, leading to increased costs.

Most homeowners spend between $30 and $75 per square foot on the cost to dig out a basement, though the age of the home, the condition of the structure, and the specific type of basement building project can influence this estimate. It’s generally more affordable to dig out a basement for a new construction than it is to deepen a basement, expand a small basement, or convert an existing crawl space.

Permits

Construction permits are a common requirement for many home renovation and remodeling projects, so homeowners can expect permits to add to the cost to dig out a basement. Permits can be acquired from the local permit office, though many contractors and excavation companies will take responsibility for getting the permits for the project and add them to the bill.

To ensure there are no mix-ups, homeowners are always advised to speak directly to the contractor or site supervisor to clarify who is responsible for getting the permits. Typically, permits to dig out a basement will cost between $1,200 and $2,000, but the exact cost may differ depending on the local permit rates.

House Bracing or Raising

When the contractors are digging a basement for a new construction, house bracing or raising is not required since the home has not yet been built. However, in order to deepen or expand an existing basement, the contractors will need to lift and secure the main structure of the home. This can be accomplished by bracing or raising the home.

• House bracing is also known as underpinning and is the most expensive option. This process involves bracing each of the existing foundation footings, before gradually raising the structure. Bracing a house adds about $20,000 to the cost.
• House raising is more affordable than bracing, with an average cost range of $3,045 to $9,379. A foundation specialist will use hydraulic jacks to lift the home, though this method has the potential to cause some minor damage to the drywall, floors, and ceilings.

Excavation

After bracing or raising the home, the contractors will start to excavate the space, removing tons of excess dirt from the property. On average, excavation costs can range from $75 to $150 per cubic yard of dirt. For a 1,000-square-foot basement, this works out to about 300 cubic yards of dirt, with a cost of $22,500 to $45,000.

Homeowners will want to speak with multiple excavation crews to get a clear understanding of the scope of work and total costs before starting this project. Excavation costs can vary depending on the type of terrain, the size of the planned space, and the equipment required. For example, if the excavation company needs to break through and remove a concrete floor, this can add an extra $500 to $1,500 to the excavation cost.

Drainage and Plumbing

Typically, when a new basement space is created or an existing crawl space is converted into a full basement, the contractors will need to install new plumbing and drainage for the home. Plumbing lines will need to be run beneath the foundation and up into the home for about $1,000 to $3,000, while the existing drainage system for the home will have to be expanded at a cost between $2,000 and $5,500.

Homeowners may be able to reduce the cost of the job if they choose to leave the utilities and bathrooms upstairs. A basement can be a great place to store holiday decorations, tools, and other items without having to install a kitchen and bathroom. Without the extra plumbing, homeowners will likely pay only $500 to $1,000 for any minimal plumbing for a boiler or other systems.

Additional Costs and Considerations

In addition to the main cost factors, homeowners can consider the impact of several additional costs on the budget. Tasks like basement waterproofing, electrical work, foundation repairs, and even door or window installation can increase the cost of this home renovation project.

Foundation Building or Repair

When a new basement is being built in an existing home, the homeowner may need to pay to install a new foundation at the same time. New foundations typically consist of the floor, the footings, and the walls, which act in tandem to support and protect the home. However, the cost to have a new foundation poured can range from $10,000 to $30,000, so homeowners will need to ensure there is space in the budget.

If the property has an existing crawl space and the homeowner just wants to deepen the space, then the home may not need a new foundation. In any case, there is a chance that the foundation could need repairs, which will cost about $5,000 on average. Foundation repair is not a DIY job, so homeowners will want to consult with one of the best foundation repair companies, such as Basement Systems or Ram Jack, to plan how to fix any cracks, holes, or structural problems with the foundation.

Homeowners Insurance

The basement and foundation of the home support the primary structure while providing a convenient space for living areas and any necessary plumbing, gas, electrical, and drainage systems. Homeowners can examine their homeowners insurance plan to see if it covers any basement or foundation expansions.

Ideally, a home insurance plan should cover between $100,000 and $200,000 for an average-size home. This amount will help ensure that if there are any significant problems, the issue can be resolved while mitigating out-of-pocket costs. Companies like Allstate and Lemonade offer some of the best homeowners insurance plans to offset costs in case of damage or disaster.

Electrical Work

Some basement projects will require plumbing lines or expanded drainage systems, but most will require electrical work to provide adequate light and power. Homeowners may choose to move the main electrical panel into the basement during a basement project, though most electrical work involves simply running wires, installing outlets, and mounting lights. Small basement expansions and even some crawl space conversions may have existing electrical systems, so not every property will require this additional cost.

If the new basement does need updated wiring and electrical fixtures, then the homeowner will need to hire a licensed electrician. How much does an electrician cost? On average, running new wiring will range from about $3 to $5 per square foot or $346 for the average job. The number of outlets and lights, accessibility, and design options can increase the cost of the job.

Waterproofing

The cost to build a basement should include basement waterproofing costs. If a basement is not properly waterproofed, then water can seep in from the soil, causing lasting damage to the contents of the basement. Basement leaks can also impact the integrity of the basement foundation, leading to high foundation repair costs.

Waterproofing will add about $2,300 to $7,600 to the upfront cost of this project, but it offers long-term savings and home protection. Homeowners can speak to one of the best basement waterproofing companies, such as Basement Systems or B-Dry, to get an estimate for waterproofing services.

Window and Door Installation

The depth, layout, and location of the new basement will determine the size, number, and location of any windows or doors. Typically, the top of a basement sits slightly aboveground so that windows can be installed to allow natural light into the dark interior. Walkout basement doors are a popular option that provide easy exterior access and additional natural light. Interior access is important, so homeowners will need to plan on paying for an inside door to the basement.

• Basement windows will generally cost about $50 to $650 per window, depending on the size and type of window.
• Interior basement doors lead from the main floor down into the basement space, giving homeowners a convenient way to access the basement. These doors cost about $375 to $1,125 per door.
• Exterior basement doors cost more than interior doors, ranging from about $525 to $2,000 per door. This type of door can turn a simple basement into a private basement apartment with a separate entrance.
• Exterior concrete steps that lead down to the exterior basement door will add about $1,000 to $6,000 to the job, and they are necessary if a walk-out door isn’t possible.

Basement Finishing

After digging out a basement for a new construction or crawl space expansion, the homeowner may choose to fully or partially finish the basement. Basement finishing generally includes putting in flooring or finishing the concrete slab, installing framework, adding a ceiling, installing drywall, painting, hanging doors, and adding furnishings. The planning phase is a great time to decide on unique basement ceiling ideas or other basement remodeling ideas.

Contractors will have already installed the necessary plumbing and electrical fixtures. However, part of the finishing process could include having contractors build countertops, mount cabinetry, and install appliances such as a new stove or fridge in a basement kitchen. Homeowners can estimate an additional $10,000 to $30,000, or about $15 to $20 per square foot, if they are curious about how much it costs to finish a basement.

Cost to Dig Out a Basement by Type of Project

Depending on the best method for the homeowner’s specific type of basement, the cost to dig out a basement can vary significantly. Building a new basement and expanding a partial basement tend to cost less than deepening an existing basement or digging out a crawl space.

Basement Deepening

Many older homes have small, cramped basements that are hard to navigate and even harder to stand up in. Despite the additional space they provide, these basements feel more like a crawl space than an actual basement, which is why many homeowners choose to deepen their existing basement. Basement deepening will generally lower the existing basement by about 1 to 2 feet.

In order to lower the basement, the contractors will need to brace or raise the house, then demolish and remove the existing floor before excavating the dirt under the foundation to lower the basement floor. Next a new concrete floor, foundation footings, and walls are installed to support the structure at the new depth. This process can cost between $40,000 and $90,000, on average.

Crawl Space to Full Basement Conversion

One of the most costly basement installation options is the conversion of an existing crawl space to a full basement. This project typically costs about $50,000 to $200,000, or $30 to $75 per square foot. The contractors will brace or raise the house before excavating the crawl space to make room for the basement installation.

When all the dirt has been removed, the contractors will expand the drainage system and run any plumbing, gas, or electrical lines into the basement. They will also have to place the forms and pour a new foundation to make new concrete walls, foundation footings, and a concrete floor. The homeowner can then decide whether to finish the new basement or leave it unfinished. If any plumbing is anticipated for future use, it should be installed at the same time as the floor. Many homeowners also opt to do some rough-in electrical work even if they plan to leave the basement unfinished for a while.

New Construction

The best time to dig a basement is when the home is first being built. This gives the excavation company ample space to work in as they maneuver equipment. It also prevents the contractors from bracing or raising an existing house, alleviating any stability concerns a homeowner may have about the process. Instead, contractors can simply mark the foundation, excavate the space, remove the dirt, and get the foundation and floors poured. Digging a basement for a new construction is one of the more affordable home excavation projects, ranging from just $10,000 to $30,000.

Partial to Full Basement Expansion

While expanding a basement costs more than simply digging a basement for a new construction, it’s typically less expensive than converting a crawl space or deepening a basement. Homeowners can expect to pay about $20,000 to $80,000 to increase the square footage of a partial basement into a full basement.

The cost difference between a basement expansion and a crawl space conversion project is that a partial basement usually has the proper plumbing, drainage, gas, and electrical already installed. Additionally, an expansion requires adding only part of the new foundation rather than pouring a new foundation for the entire basement.

Digging Out a Basement: DIY vs. Hiring a Professional 

There are a wide variety of home renovation, remodeling, and repair projects that can be tackled by an experienced DIYer, but digging out a basement is not one of those jobs. It takes a significant amount of skill, experience, and knowledge about the structural design of a building for an individual to come up with a plan to dig out a basement. That’s why most excavation companies will have at least one structural engineer on staff, since the safety and security of the home’s occupants rely on the expansion being done properly.

Contractors use specialized equipment to brace or raise the existing structure in addition to the excavation equipment. Most homeowners are not familiar with these tasks and pieces of equipment. It’s also worth noting that many municipalities require licensed contractors to handle certain types of construction tasks—many of which are included in a basement excavation project.

Each part of a basement dig-out job requires levels of expertise that homeowners don’t typically have, whether it’s laying foundation, installing plumbing, or bracing a house. Allowing a pro to handle these jobs lets homeowners worry less about the security of their home when the project is done.

How to Save Money on the Cost to Dig Out a Basement

The cost to dig out a basement can range from $60,000 to $150,000 due to the expensive costs of bracing and raising the home before installing proper plumbing and drainage. While there aren’t a lot of ways to save on such a large construction project, there are still ways homeowners can save money in the long run.

• Bundle services for a reduced rate. Adding extra services, like waterproofing or foundation repair, to the basement building project may lead to a reduced rate for the work and save on repair costs down the road. Homeowners may even get a cheaper price for concrete by the yard if they have a new foundation and driveway poured at the same time.
• Invest in a full basement. The upfront cost of the job will be higher than the cost of a partial basement excavation, but the additional space can increase the value of the home, leading to a better return on the investment.
• Waterproof the basement. By waterproofing the space, homeowners can protect the contents of the basement, as well as the floor, walls, and foundation footings, reducing any future repair costs.
• Build a basement at the time of construction. When homeowners have the option, adding the basement at the time of new construction is much cheaper than adding it later.
• Consider a home addition instead. Digging out a basement can help increase the available living space in the home, but it typically costs more than building a home addition. If the property has enough space, homeowners can consider building a home addition instead of digging out the basement.
• Leave it unfinished. Homeowners can save on upfront costs if they leave the basement unfinished with just the foundation, concrete floor, and perhaps some basic electrical work.

Questions to Ask About Digging Out a Basement

Collecting information ahead of time is important for homeowners wanting to understand the costs, risks, and process of digging out a basement. Homeowners are advised to ask several contractors some key questions about the company, job estimates, payments, project schedule, and excavation process.

• What experience do you have digging out basements?
• Do you have references available?
• Are you licensed, bonded, and insured?
• Can I see a portfolio of past projects?
• What does the estimate include?
• How long has the company been in business?
• Who will do the inspection, and what qualifications do they have?
• Is it better to brace or raise the house?
• What safety precautions will you take?
• Who is responsible for any potential damage caused by bracing or raising the house?
• When is payment due for this job?
• How long will the project take?
• What access will you need for equipment during the excavation process?
• What are your working hours, and will someone need to be home at all times?
• What permits do I need, and will you obtain them?
• Do you do all the work yourself or hire subcontractors?
• If I plan to have new plumbing or electrical work installed, will you schedule that service?
• What additional or unexpected costs could I expect?
• Do you offer a warranty?
• When will you start?
• Do you offer financing?
• Is cleanup included?

FAQs

Digging out a basement is a complex job that is not recommended for DIYers. Instead, homeowners will have the best outcome if they hire a crew of trained and knowledgeable professionals who can assess the situation, come up with a plan, and put that plan in action to complete the project safely. However, it’s still a good idea for homeowners to learn as much as possible about the process so they can feel comfortable about the project and ensure that the outcome is what they desired.

Q. Can I turn my crawl space into a basement?

Converting a crawl space into a full basement is possible, but the project is complex and time-consuming and can cost between $60,000 and $150,000. With this in mind, homeowners will want to speak to an excavation and basement building expert to determine the best way to convert the existing crawl space.

Q. How do you estimate excavation work?

In order to estimate the cost of excavation work, a contractor will determine the length, width, and depth of the excavation zone. They’ll multiply these measurements to get the approximate volume of the space, then multiply the total volume by the price per cubic yard. This price is set by the excavation company to cover labor and equipment costs. The average excavation cost range is $1,515 to $6,211.

Q. Does a basement conversion require a permit?

When converting a crawl space to a basement, deepening a basement, or expanding a partial basement, homeowners are required to obtain the proper building permits. Generally, the excavation company or on-site contractor will take responsibility for getting the permit, though in some cases the homeowner may need to head to the local permit office to pick one up before work can legally begin.

Q. What adds the most value to a basement?

A good reason to dig out a basement is to increase the square footage of the home. This alone can add to the value of the home, but if the goal is to raise the value of the property, then installing a bathroom during the basement building project is a great option. An additional bathroom in a basement can increase the value of the home by up to 20 percent.

Sources: Angi, HomeAdvisor, HomeGuide, Actuate Improvement