The Ultimate Guide to Basement Conversions in the UK

The idea of converting your dark and unused basement can be beneficial both in terms of your house value and lifestyle. This is one of the best way to get more rooms or a place to hang out without having to move. In recent times, basement conversion is becoming more and more popular especially in areas where it’s comparatively difficult to extend your house or move up.

We have put together this comprehensive guide to show you exactly what you need to consider when starting your basement conversion project.

Why You Should Convert Your Basement

With basement conversion, you can not only add space to you home but also make sure that your home works better for you. Some of the common reasons for a conversion are:

1. Adding Extra Living Space

Whether you are looking to add some extra rooms to your home or just want a place to work or hang out, a liveable basement can serve all your needs without you having to compromise on existing home structure. A basement is basically a blank canvas and you can design it however you want.

2. Adds Real Value to Property

You can easily boost your property’s value by as much as 20 percent by getting a proper basement conversion. So not only will have add comfort to your home, you will also be appreciating your asset value.

3. Cheaper Than Moving

Moving out to a bigger house is costly and it can be unsettling especially if you love your neighbourhood. A basement conversion can be cheaper compared to moving out and you can easily add more space as per your needs.

4. Energy Efficiency

Since basements are underground, they naturally stay warm in winters and cooler in the summers. Costs of heating and cooling can be significantly reduced as compared to upper floors.

Do You Need Planning Permission

Planning permissions are totally dependent on what sort of situation you are dealing with and what type of work is required.

Scenarios Where Planning Permission Is Not Required

A planning permission is usually not required when you already have a basement and just want to convert it into a useful living space or bedrooms. You will still have to following building regulations when converting your space to make sure that it meets all the required standards.

Scenarios Where Planning Permission Is Required

If you don’t have a basement and need to dig out a new one then you will definitely need planning permissions. In other scenarios, if your house is listed or you live in a conservation area or even if you want to change the elevation of the property then you will need to get permissions.

It’s always a good idea to check with your local counsel before starting basement conversion especially areas like London where they have extra rules about basement works.

What Building Regulations Are Applied

Even if you don’t need planning permission, you will still have to adhere to building regulations to make sure that your home is safe and the basement doesn’t create any future issues. You need to follow the following building regulations:

Structure: Making sure that the walls and floors of basement are strong enough to bear the load of whole property.

Waterproofing: Proper waterproofing needs to be done to protect the basement space from leaks and damp.

Ventilation and insulation: The space needs to be energy efficient so it feels comfortable all through the year.

Fire safety: Make sure there is an escape route and alarms in case there is a fire mishap.

Ceiling height: As per regulations, the ideal ceiling height should be atleast 2.4 metres after the conversion is done.

All these regulations can be managed by a qualified structural engineer or architect and they can work with Building Control on your behalf.

Keeping Water Out

The most important aspect of a basement conversion is waterproofing as the space is below ground and you will need proper protection from soil moisture.

There are two methods to do waterproofing:

1. Tanking System

If your basement doesn’t have a major issue of water and moisture then coating the walls and floors with waterproof layer is sufficient.

2. Cavity Drainage System

Cavity drainage is usually the most viable and appropriate approach when it comes to waterproofing. This method uses a membrane and drainage system to channel the collect water into a sump pump.

Whatever method you use to waterproof, you will have to strictly follow the BS 8102:2022 standard which is the British Standard for waterproofing below ground.

How Much a Basement Conversion Costs

Costs of a basement conversion depend on various factors like the size of your space, the area where you live and how type of finishing you want.

Here’s a rough idea:

As an example, a typical basement conversion for a home in London might cost you between £80,000 and £250,000 and although it sounds like a lot but in areas where property prices are high, the added value will be totally worth it.

How to Make Your Basement Bright and Welcoming

Usually basements don’t get much natural light so you need to design it in a way that it looks more bright, welcoming and pleasant. Here are a few tips that might help:

• Try to add light wells and sun pipes wherever you can and as much as you can.
• Use plenty of LED spotlights instead of just using plain old ceiling lights.
• You should try to stick to light colours for paint and flooring to make the space feel more roomy and pleasing.
• You can use mirrors smartly by placing then in strategic places to light reflects properly making the rooms or space look bigger.
• Underfloor heating is a good option as it keeps the basement cosy and also frees up wall spaces.

How Long a Basement Conversion Project Take

The time to complete your project varies from project to project but here is a general idea:

Converting an existing basement: 8 to 14 weeks

Digging a new one from scratch: 20 to 40 weeks

This time frame includes everything from the planning phase up till the finishing. Though this time can increase if you are working with a relatively old house of the soil conditions are a bit worse than usual cases.

Choosing the Right Basement Conversion Company

A perfect basement conversion requires an experienced company that have experienced team to handle all the structural work, waterproofing, plumbing and electrical. You cannot hand over this type of project to just any company and you should always look for following when choosing a specialist:

• Proven track record of successful basement projects
• Can give you guarantees for fail-proof waterproofing systems
• Have public liability insurance
• References or case studies that you can verify yourself
• Are a member of organisations like the Federation of Master Builders or TrustMark

Pro Tip: Always be careful with quotes that seem too cheap as a basement conversion done badly can lead to big problems later in the future.

Looking After Your Basement

You have to properly take care of your basement when it’s ready. Keep up to date with regular maintenance to keep everything in order.

• Test your sump pump and drains every year to make sure that you don’t have any water leaks
• Check all the corners and joints for any damp patches and if you see some, make sure to get it fixed soon
• Make sure all the vents and air systems are clean and working to keep the space comfy and neat
• Keep outside drains and light wells clear of any debris

If you maintain your basement properly and keep everything in check, your basement will stay dry and comfortable for many decades.

Final Thoughts

Converting your basement is one of the best ways to add both space and value to your home without moving to a new home. It’s a big project but when done right, it completely changes your living experience.

Always plan carefully, get good advice from experienced professionals and only work with specialists who know what they’re doing. Once the project is finished, you will have a space that will make your living experience a lot more enjoyable and practical.