Can you build a basement under a house in the UK?

Adding a basement to your home can bring many benefits with the additional space; it can be used for extra storage, to create a new bedroom or an office space, and it can easily be built with its independent access, so to add exceptional value to an existing house.

But is it legal to build a house with a basement and what is the planning permission process?

To answer all your questions, we’ve put together a complete guide on building a house with a basement in the UK.

Is it legal to build a house with a basement in the UK?

Whether you’re digging a basement under your existing home or have one planned in your new property design, building a basement is usually legal.

In most cases, you will have to get planning permission from your local council, In the year 2017 there was a 183% increase in homeowners submitting planning applications to dig under their own houses. In fact, getting planning permission for a basement is straightforward, because basements have a very low impact on the exterior of an existing building and in general in a neighbourhood.

Do you need planning permission?

Whether you need planning permission for basement building at all depends on where you live, your property, and what exactly you’re looking to build.

If you’re just looking to convert your existing basement, it is possible that you won’t need any permission, unless the outside appearance of your home is being altered. But, if you’re actually digging into the ground below your home, you most likely will need planning permission – which is relatively easy to get.

One important thing to keep in mind, though, is that usually planning permissions to excavate basements are granted with several conditions; these are requirements from the council on construction methods, process, site management, traffic management, safety on site, that are meant to be discharged once the construction starts and as it progresses.

Planning permission regulations for basement construction

To obtain permission to build your own basement, you’ll need to adhere to both the country-wide regulations as well as your local council’s, which may be stricter depending on where you live.

We recommend you hire an architect to be in charge of your planning permission application and the design of your basement, and that you appoint an experienced construction company to do the work.

Planning conditions are usually quite strict and you will need a professional construction company to be able to discharge them. Plus, excavating a basement is complex and requires accurate procedures on site, especially around safety and temporary structures.

You also have to check whether you need to serve a party wall notice for your basement project. For example, a notice is due if you are excavating below a certain distance from your neighbours walls and foundations. 

Getting planning permission for a basement is very simple, and it’s definitely worth it considering the benefits of the extra space. Nowadays it’s easy to create a basement that is completely waterproof, well aerated and has still plenty of sources of natural light.