In the UK, when somebody says that they are extending their home we tend to think of lofts, conservatories and rooms above garages, without contemplating that it might be a basement conversion.

In America, basements are commonly used as utility rooms, family rooms, gyms or entertainment areas to be proud of. Here in the UK, the majority of us that have an open cellar use it for storing things that we don’t really need, as a dumping ground or to keep the wine and beer cool.

And most of those that do not have a readily accessible cellar have never given the idea of digging down a second thought, or even a first thought. Most people are simply unaware of the options available to them, and the fact that modern construction methods will allow for some incredible developments to your house.

It is amazing what you can do

A factor that may put you off when considering the idea of a basement conversion is the dark and stale state that it is currently in. It may seem like an impossible task to turn it into somewhere you would actually want to spend time. But, with the implementation of modern methods your dingy cellar can be transformed into a bright and comfortable space in no time at all; well, a matter of weeks!

With regard to the suitability of homes for this type of development, the perfect candidates are terraced or semi-detached urban properties where it may be impossible to get a conventional extension or to extend into the loft. Other good candidates are homes that have already been extended to their maximum with no more room for external expansion.

The great thing about the basement is that it is suitable in terms of location for gyms and even indoor pools, rooms that seem impractical, or an absolute impossibility in the loft or above the garage.

Converting your basement tends to be more costly than getting a conventional extension or loft conversion, and though you should be careful not to exceed the limitations of your area in terms of resale value, it could boost the value of your house by up to 30%. After all, it is adding a whole new floor to your property and in some properties it will run the length of the whole house.

The ideal candidate then for a development is of course a house with an existing cellar or basement, usually built pre 1930as it just easier and more cost efficient. Properties lacking the attributes of the perfect candidate can be transformed just as effectively, only they have to be dug out from scratch which is far more expensive and time-consuming.

Any additional digging to combat restricted headroom in a property with an existing cellar is perfectly possible, but will add to the cost of your project. A recent development has allowed for the possibility to construct new basements under concrete, where previously they could only be built in properties with suspended timber floors.

If you have decided you want to develop your cellar space, or at least you want to enquire about the feasibility of any development, you need to contact a specialist company and get them to come and asses your home, and address any of your concerns along the way.

The process

If there is to be any digging down, either for additional headroom or the creation of a whole new space the foundations must be underpinned, which involves extending them downwards for extra support.

Once the space has been created, or if you had an existing space, you will recognize that the major priority in turning it into a habitable room is getting it waterproofed. This is done via a cavity drainage membrane which lines the walls and offers drainage for any water that seeps in either by directing it into a conventional drainage system or a collecting sump with a pump.

Your options

Because of the specialised nature of the task of converting a basement it is highly advisable to hire experienced professionals.

There are three ways of going about getting your basement converted into the space of your dreams:

1 Hire an architect to draw up your plans, recommend contractors and oversee the build.

2 You may prefer an approach that keeps you involved, you may know the right people to cut some costs or you may just fancy a bit of a challenge. If so, take on the role of project manager, finding contractors and overseeing the build yourself and using the architect only for his plans.

3 Conversely, you could stand back and let a basement conversion company handle the project in its entirety. Everything from planning applications to kitting it out once it is finished will be their responsibility. This can be the most expensive but also most stress-free option.

Regulation and law - the boring stuff

Developments to terraced or semi-detached homes will need the approval of the neighbouring residents and you will have to hire a surveyor to check out any possible problems with regard to subsidence or damage to shared foundations.

Unless you are planning for your development to create new habitable space, include the adding of a light well or change the external appearance of your property, you should not need planning permission. It is always worth checking with your local planning department just in case. Also, because the work you are undertaking is structural you will need buildings regulations consent

Designing and planning - the fun stuff

Converting your basement can be a great chance to be really creative and downright indulgent it can be your spot of luxury in what may be an otherwise quite ordinary house, the pièce de résistance if you will.

There is one thing that you do not want though; you do not want your basement to look out of place and it should be the jewel in the crown, not a jewel on a flat cap, stuck down with super glue!

Your basement should look like it has always been there and so blending it in with the existing structure and style of the rest of your house is extremely important.