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Can You Add a Basement To a House? What You Need To Know!


Basements have a ton of benefits. They are great places for storage, they can be finished to create hundreds of extra square feet of living space, and they add value to homes around the world. These benefits entice homeowners all of the time, but many of them find themselves sitting in homes with no basement. This brings us to an important question, can you add a basement to a house? If a home was not built with a basement, can one be built after the fact? It is a question that many people would like to know, especially those suffering from basement envy.

The answer to this question is not simple. It is complicated. The simple answer is yes, a basement can be added to a house, but there is a catch—or perhaps a few. Read on for the full scoop.

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Basements Can Be Added In Most Structures

Anywhere where basements are built regularly can support the building of a new basement under a home. If a home is over a crawl space, building a basement is definitely possible. If a house is built directly on the ground or on a slab, the job becomes much more difficult and, in some cases, impossible.

Not all ground is conducive to building basements, but anywhere that the ground can support fresh digging under a home should be able to support the construction of a brand-new basement. In order to make that determination, an inspection will have to be done by a licensed professional. Someone needs to examine the foundation of the home and the soil underneath to determine whether or not a basement is possible.

The process of adding a basement where none existed before includes digging out the area, raising the house of the foundations, adding new footers, redoing the foundation, and then finishing up the basement area.

construction of basement
Image Credit: Andrei Kholmov, Shutterstock

There Are Places Where Basements Can Never Be Built

Not all places are suitable for basement construction. There are places with marshy, swampy, or sandy ground where basements cannot be built. Places like Florida have extremely shallow aquifers that prevent any digging down more than just a few feet. Other places have loose soil that makes digging dangerous and prone to shifts over time.

Anywhere where basements cannot be built during new construction also prohibit the building of basements after the fact.

It May Be Cost Prohibitive

While basements can technically be added under a home after the house has already been finished, it rarely happens because the process is cost prohibitive. Digging a completely new basement under a home is an involved process that can cost upwards of $150,000. Even homes that already sit over a crawl space can expect to shell out $50,000 to turn that crawl space into a basement.

Few people are willing to pay that kind of money to add a basement under a home. The most inexpensive time to build a basement is during initial construction. Building a basement during initial construction also faces the fewest risks to the home itself.

housebuilding construction site
Image Credit: Ralphs_Fotos, Pixabay

There Are Other Risks

On top of being expensive, adding a basement also comes with a considerable amount of risk. Digging out a home’s foundation can lead to issues down the line. Any mistakes during construction can cause a home to shift and settle. This can lead to damage or lingering issues long after the basement is finished. It takes a team of highly trained and skilled foundation experts to properly build a basement under an existing home.

As a rule, it is never good to mess with a building’s foundation unless there is an issue. Willfully digging up a foundation and resetting it under a home already built is asking for problems.

basement window repair
Image Credit: Pavel L Photo and Video, Shutterstock

Alternatives To Adding a Basement

Taking the risk and the cost into account, few people are willing to put up with either to get some extra square footage or storage space. For $30,000 to $150,000, people can get a lot of value with much less risk. Alternatives to adding a basement under an existing home include an addition, a barn or garage, or a complete remodel to make the home work better for you.

A typical home addition can add loads of covered living space for much less than a basement. Adding a finished garage can give you the storage or living space that you are craving without digging up any foundations. Lastly, reinvesting the money that would have been spent on a basement into a full remodel can add more value long term.

In almost every case, doing one of these things is a better use of money than adding a basement. That is why seeing basements added after a home is built is so rare.

basement under construction
Image Credit: ungvar, Shutterstock

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The best time to build a basement is when a home is being built for the first time. Technically, adding a basement is possible after the fact, but it is so expensive and so risky few people dare to try it. Instead, most people will settle for a new garage or addition that serves the same purpose as a basement without the added risk or costs.

Featured Image Credit: Anatoli Igolkin, Shutterstock


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