The Cost of Remodeling a Basement by Square Foot
Basement remodeling costs can vary widely, and are heavily influenced by the additions you plan to make and how much demolition will be required. The average basement renovation costs $30 to $75 per square foot or more, depending on the amount of work needed.
Not sure how big your basement is? Here’s a look at the average square footage of basements:
Basement Size | Average Square Footage |
---|---|
Small basement | 300 – 700 sq. ft. |
Medium basement | 700 – 1500 sq. ft. |
Large basement | 1500 – 2000 sq. ft. |
Oversized basement | 2000 – 4000 sq. ft. |
Remodeling a basic space, like a family or recreation room, falls on the lower end. But a remodel with a larger footprint, such as installing a bathroom, will cost more per square foot due to installing walls, plumbing, and ventilation.
How Much Do Basement Renovations Cost by Type?
If your basement is already finished, the sky is really the limit in terms of remodeling possibilities. Depending on your needs and budget, this often forgotten space can be transformed into nearly anything that could typically be found on the upper levels of your home.
With that in mind, the cost of remodeling your basement is only limited by your imagination—and your budget.

Additional Bedroom
If things are starting to feel cramped upstairs, adding a bedroom in the basement might provide more breathing room—not to mention another bedroom on your spec sheet if you sell your home down the road.
However, be aware that this remodel project has very specific codes and guidelines that must be followed. In addition to walls and floors, a bedroom must also include a closet and a window that is large enough to provide an emergency escape if the stairs are inaccessible.
A basement bedroom remodel that includes all the necessary components costs anywhere from $3,000 to $10,000.
Adding a Bathroom
If the upstairs powder rooms aren’t cutting it for your household anymore, consider adding a bathroom on the lower level. A basement bathroom installation will cost anywhere from $6,600 to $16,500 but can have an ROI of 63%, according to the 2022 Remodeling Impact Report from the National Association of Realtors.
If you already have plumbing in your basement, you can expect your costs to fall on the lower end. But if you need plumbing, framing, floors, and ventilation installed, your costs can reach the higher end of the average.
Creating a Home Theater

Take movie night to the next level (the bottom one) with a tricked-out home theater. Creating a basement theater with all the bells and whistles, including seating, sound system, projector, and large screen, will cost around $12,000.
Building a Bar
Building a basement bar can be an ideal centerpiece for entertaining at home. From prefab DIY islands to custom pieces with a sink and tap handles, the possibilities are endless. An average basement bar installation costs $8,000.
Establishing a Home Gym
There’s no excuse to skip a workout if you only need to walk downstairs. While certain machinery like step climbers might not work in a basement with lower ceilings, popular gym equipment such as treadmills, weights, and punching bags would all fit nicely.
Depending on the components you include, a basement gym addition ranges from $300 to $15,000.
Creating an Office Space
If you work from home, be it full- or part-time, it may be time to create a more permanent and productive office space away from the household noise. A basement office costs around $500 to $3,000, depending on how high-end you’d like it to be.
Adding new lighting, framing, flooring, and a door are all potential components that can be included (at a cost).
What Factors Influence the Cost of Remodeling a Basement?
The type of remodel, any rooms you are adding, and the complexity of the design will all influence the cost of remodeling your basement. Even small improvements, such as upgrading to higher-end fixtures and flooring, can quickly tack on several thousand dollars.
Here are a few factors you need to consider when estimating your renovation costs, outside of just the type of room you’re building.
Size and Condition of Basement
Of course, a larger basement will be more expensive to remodel—just as it will be more expensive to update a basement with water damage.
If you’re simply making cosmetic updates, like changing the flooring or painting the walls, your remodel costs could add up to only $2,000. But if you have to completely gut your basement and start from the studs, your costs will be much greater.
Labor and Materials
While you can complete some straightforward basement remodels by yourself, larger projects are best left to an experienced professional. That’s especially true if you don’t already have equipment and materials on hand. A reputable company will come out to complete site inspections, take measurements, make material recommendations, and suggest layout options.
Plan to budget 6% to 10% of the cost of your home for a professional basement remodel, including labor and materials.
Permits and Inspections
Make sure to budget permits as part of your basement renovation costs. While the specifics will depend on the county or city where you reside, most basement remodel permits range from $500 to $2,000.
If you are working with an experienced company, they will typically take care of obtaining permits, but be sure to read the details of your contract and verify this piece.
Additional Costs of Remodeling a Basement
When estimating the cost of remodeling your basement, you should add about 20% to the top line for incidentals, like repairs, mold removal, and asbestos removal. That way, if you run into any issues you already have the money available.
And if you’re lucky enough not to run into unexpected costs, you can use that extra money however you see fit—like adding that theater room.
Repairs
Some of the most common repairs you may face when remodeling your basement have to do with your foundation, plumbing, and electrical wiring.
Foundation
If you notice cracks starting to develop behind your drywall or underneath your newly ripped-up flooring, it may be a sign that your foundation needs attention.
Minor repairs (like a small crack in the floor) are relatively affordable to fix, usually around $500.
But if you need to jack the foundation or fix leaks, your costs may be more. According to HomeAdvisor, the average cost for foundation repair is between $2,000 and $7,100.
Plumbing
Does your basement smell musty? Does water collect in certain spots after a big rainfall? You may need to add a french drain or install a sump pump.
The cost of these projects depends on the size of your basement and the severity of your issues.
Electrical
Electrical issues can hide in your basement for years without you ever knowing they exist. For example, your wiring may not be up to code, or water damage near your wiring could lead to disaster if not treated. Or maybe your wiring just isn’t up to par for the big plans you have for your remodel.
Whatever the case, it’s best to leave all types of electrical work to a professional. Depending on the work that’s needed, you’ll pay between $85 to $1,000 for an electrician.
Mold Removal
Basements are prone to water damage. When removing drywall or flooring, you may find that mold has started to grow in your basement. If it’s a small amount of non-toxic mold, you can treat it yourself using a DIY mold removal method.
But in most cases, mold is best left to professionals. Professional mold removal can run you between $1,100 and $3,300, depending on how severe the outbreak is.
Asbestos Removal
Asbestos may be a concern during your remodel if your home was built before the 1980s and your basement has vinyl flooring or millboard installed between 1952 and 1982.
There’s no DIY test for it (nor should you try to test it on your own). If you’re at all worried about asbestos, it’s best to hire a local asbestos removal company. It is not something you should tackle on your own, as mishandling can lead to mesothelioma and other asbestos-related conditions.
If you have asbestos, you should expect to spend an average of $2,100 to remove it.
DIY vs. Hiring a Pro
As you can see, the cost of basement remodeling depends on many factors. If you already have a finished basement and are only adding some minor finishes and upgrades, you may be able to save money on labor by doing it yourself. But if you’re inexperienced or short on time and tools, hiring a local contractor to do the work for you can be well worth the money.
Your general contractor will handle everything from project planning, ordering materials, scheduling deliveries, installation, and more—pretty much anything and everything in between.
A general contractor costs about 10% to 20%of your basement remodel cost. So if your basement renovations costs are $40,000, you’ll likely pay a contractor anywhere from $4,000 to $8,000 for their time and expertise.
And while that may seem like a lot of money, you can save a lot of time and energy by working with a professional.