Is it worth investing a basement conversion?

admin Basement conversion

People often ask us whether it’s worth the investment and upheaval of a basement conversion to add value to their property. In this post, we consider what are the best ways to add value to your home, and is converting your cellar to add extra space one of them?

There are many ways to add much-needed space to a family home, including converting a loft or basement or adding a conservatory or extension. If you like the area where you’re living, and it costs less to turn your three bedroom house into a four bedroom house than it does to move, why bother with the stress and disruption of a move?

In many cases you don’t need to seek planning permission for either a loft or basement conversion. However, properties such as listed buildings or those in conservation areas will require planning permission, so it’s best to contact your local planning authority in advance.

So what are the main options and how do they compare?

Attic conversions

These are typically used to add an extra bedroom and perhaps an en-suite. For an attic conversion to be feasible, the ceiling height should be at least 2.3 meters to give enough headroom. Generally the steeper the pitch of the roof, the more suitable it is for conversion.

Skylights will help you create a cheerful space with plenty of brightness. Dormer windows are also an option, and can add head height, but will require planning permission.

However, a loft conversion will only ever give a limited amount of additional space, especially in comparison to a basement conversion. Head height is often restricted due to the original height of the roof and that of your neighbour’s roof. You should also think about access – a staircase means losing space on the floor below. If you have to sacrifice too much space or make the downstairs rooms an awkward shape, it may not be a worthwhile investment.

Basement conversions

For more space, or for those who’ve already extended into the roof, a basement conversion can be a great choice.

But what will you use the space for? This will affect the design and building process as well as the cost, so it’s an important first step. A cellar conversion could make a wonderful kitchen/diner, or a second living room, a home study or a games room. Or why not think big and convert your basement into a pool, a wine cellar, a gym or a garage, like the ‘iceberg properties’ of the super-rich featured here!



Many people who embark cellar conversions tend to already have an existing cellar, meaning much of the dig-out work is already done. However, additional excavation can be necessary, meaning structural work and extra waterproofing. The main issues to resolve are normally low ceiling heights, damp and a lack of natural light, all of which can be remedied with help from a specialist company like Multiskill.

Living space

A cellar conversion for extra living space

Ask around for recommendations and testimonials when looking for who to convert your cellar. Ask how long the company has been in business and make sure that the work will be done by that company – not a subcontracted team.

You may not need planning permission for your basement conversion if the changes only involve waterproofing and not excavation or underpinning. However, if you live in a terrace or semi-detached property and are excavating, underpinning or extending an existing cellar, you must take note of the Party Wall Act. Your neighbours can’t stop you from making legal changes, but they are entitled to a say in how and when the works are carried out.

party space

Or even an amazing party space!

The good news is that a cellar conversion can add 10-15% to your property’s value, according to Savills. And once complete, a good basement conversion should allow a higher ceiling in comparison to the low, sloping ceilings of a typical loft conversion. Depending on time and money, you can even extend beyond your house and under your garden, making it an effective way to give you a potentially large amount of extra living space. 

If you want to know more about basement conversions, contact Multiskill now for a no obligation site survey and initial consultation.