Guides and Tips

How much will it cost to dig a basement deeper?

July 29, 2022
How much will it cost to dig a basement deeper

Building a deeper basement is a costly job often ranging from $10,000 to $100,000. Generally, you can expect to spend $30 to $75 for each square foot of the added basement.

Now prices won’t always be the same for each project. Different factors to consider include the basement size, waterproofing, plumbing and drainage, and permits.

So, let’s take a closer look at each of these factors and how much they will add to your total project cost.

Basement Size

Basement Size

The most obvious price factor for digging a basement deeper is the size. Take into consideration the length and width of a room.

Size measurement for this type of project is often in square footage.

Basement renovators typically charge $30 to $75 per square foot of the newly constructed basement. So, the larger the usable space you want to build, the more you will pay.

Do note, however, that merely raising the low ceilings of your current basement won’t affect this factor, as technically, your basement still has the same length and width as before.

In this circumstance, you will just pay the applicable construction costs to your chosen builder.



Waterproofing is an essential aspect of building a basement. This prevents moisture and leaks from entering your basement, which can cause unwanted water or mold and mildew damage.

The type and method of waterproofing used will vary based on your home style and location. But, on average, waterproofing a basement costs between $1,920 and $6,493.

Plumbing and Drainage

Plumbing and Drainage

The newer and deeper basement must also be fitted out with plumbing and drainage lines. This is so you can use and dispose of water in your basement conveniently like in the rest of the house.

Now this job can be a bit complex depending on whether you already have existing pipes under the floor. Some of which have to be removed or rerouted. 

Also if you have a septic tank or sump pump, the work and price will be different.

Calling a licensed plumber can cost you anywhere from $45 to $450 per hour.



Since digging a basement deeper will most likely require excavation, the homeowner would need to secure a permit to carry out the work legally. However, some basement works won’t require it at all.

Therefore, we recommend checking with your local government agency first before starting the project.

Also, permits come in different types, but what you will need will mainly depend on your location and the type of property. This should add another $200 to $1,000 to your final bill.

More Basement-Related Contractors Lists

You might also want to read these service lists to find a qualified and experienced basement contractor:

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