A cellar conversion can be a solution for those who want more space but do not want to move out of their area, or want to avoid the costs associated with moving. A basement conversion can add 20 to 30% to the value of the property. Older style properties are usually more suitable for a basement conversion as they have suspended timber floors. There does not always need to be an existing cellar. It is possible to create a basement for a modern property, but this is more complex.

Planning Permission

Planning permission is not usually needed for a cellar conversion, but it may be required if it involves a change of use such as converting the cellar to a garage or an office. Planning permission may also be needed if the property is a listed building, or is in a Conservation Area. Local Council offices can give more information. Visit our Council Links section to find the web site for your local Council Office.

Building Regulations

Loft Conversions and Pricing
Whether or not you need planning permission for your basement conversion you will need to comply with a number of Building Regulations. These regulations cover such things as fire escape routes, ventilation, damp proofing, electrical wiring and water supplies. In addition, structural underpinning and foundation work is likely to be required. It is advisable to get expert advice on the design of your cellar conversion so that you can ensure all these areas are adequately covered before plans are submitted. There is also the Party Wall Act 1996 to consider. If you do not inform your neighbours about what you intend to do they could stop the work.

Heating and Ventilation

Heating and ventilation of your basement conversion is crucial. The cellar will need to be waterproofed. It may be possible to use a liquid for this but expert advice should be sought. Air bricks and extractor fans should be included in the design to ensure adequate ventilation of the new room(s). For the heating, any work involving gas must be done by a Corgi registered fitter, or you could use electric heaters or add radiators to an existing boiler if the boiler has sufficient capacity.