How long does it take to add a basement to an existing house

If you’re looking to expand your property, building a basement could be the best way to maximise the use of limited space by extending below ground level.

In the UK, it’s possible to convert existing cellar spaces into basements or to underpin an existing house and excavate a new basement from scratch.

In this article, the team at Danford, Brewer & Ives explains everything you need to know about building a basement under an existing house in the UK.

How to Excavate a Basement Under an Existing House?

Given the scarcity of land in the UK, building a basement beneath our feet is often the best option if you’d like an extension. Basements can add huge value to properties while providing a functional living, entertainment, storage or utility space that’s highly customisable.

But can you build a basement under an existing house in the UK? The short answer is yes, and it’s possible even if there’s currently no subterranean space (such as a cellar) below the property.

This can be achieved by excavating the area beneath your home, through a method that’s known as underpinning. Underpinning is a technique used to extend existing cellar spaces in order to create more room, while the technique can also be used to create an entirely new space that can be converted into a basement.

The underpinning process sees qualified engineers excavating the soil below the foundations. This space can be filled with concrete or other sturdy construction materials that ensure the foundations of your property remain as strong as before. Above this, you have a newly excavated space that forms the basis of your basement.

Once the underpinning has been achieved, the basement can be created. As part of this process, your engineers will need to factor in integral structural elements like drainage, waterproofing and lighting. When the basement has been built, the final stage is the interior design, decoration and furnishing.

How Much Does It Cost to Build a Basement?

Now to the all-important question, how much does it cost to build a basement? Unfortunately, there’s no exact figure, as there are a number of variables that any basement conversion project needs to factor into its budget.

The most important variable is often whether or not there’s an existing cellar space below the house. If there is, this can seriously lower costs, as the existing work can be expanded on. If you need to start afresh, a new build basement cost in the UK will be significantly higher, as more work will be required.

Other important variables include:

• The size of the basement conversion
• The complexity of the basement conversion
• The materials used in construction
• The interior design, furnishings and decoration

We should note that building a basement is a serious project that requires a comprehensive budget in order to be completed safely. Always use a professional service and the best available materials for the best results.

How Long Does Building a Basement Take?

As with cost estimates, it’s difficult to pinpoint the exact timeframe in which it takes to build a basement. This also depends on a number of variables, but you can expect any basement conversion to take a number of months from start to finish.

To help you visualise the process and how much time this may take, it’s important to consider that there are several main stages involved in the design, excavation and construction of a basement beneath an existing house in the UK. These are:

1. Planning, initial design and surveying
2. Excavation and building work
3. Interior design and decoration

These factors will of course vary. The larger and more complex a basement conversion is, the longer it will take to complete. If you have an existing cellar space, it can lower the timeframe whereas excavating a basement from scratch will take much longer.

Contact Danford, Brewer & Ives to Find Out How We Can Make Your Basement Plans a Reality

If you’re planning on building a basement, Danford, Brewer & Ives has an expert team of basement converters ready to assist.

From the initial survey and design stages through to excavation, underpinning, waterproofing and interior decoration, we provide a professional, full-service basement conversion package tailored to your needs.

Contact Danford, Brewer & Ives today to find out how we can make your basement dreams a reality.

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.

Basements Can Be Added In Most Structures

Anywhere that 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.

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.

• Related Read: Can I Build My Own Garage? Costs, Risks, and Considerations

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.

• See Also: Can I Build My Own Deck? Risks, Costs, and Considerations

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.

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.

• See Also: 21 DIY Garage Organization Ideas You Can Build Today

Conclusion

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

Contents

• 1 Basements Can Be Added In Most Structures
• 2 There Are Places Where Basements Can Never Be Built
• 3 It May Be Cost Prohibitive
• 4 There Are Other Risks
• 5 Alternatives To Adding a Basement
• 6 Conclusion