The planning system defines the different uses of buildings, and separates them into different classes. In most cases planning permission is required to change the use of a building from one class to another, although permitted development rights do allow for some uses to change to a different use without the need for planning permission. See our pages on Change of Use for more detailed information.
Planning permission will almost certainly be required for change of use of a residential property to a retail use.
The majority of local authorities have designated shopping or commercial areas within their planning policies where shops and other commercial uses are encouraged. It is likely to be very difficult to gain permission for a retail use outside of these areas especially in an area that might otherwise be wholly residential.
The regulations define converting a home into a shop as a 'material change of use' and specify the requirements with which, as a result of that change of use, the building, or the relevant part of the building, must comply.
The specific requirements include those concerned with escape and other fire precautions, hygiene, energy conservation, and access to and use of buildings.
The building may therefore need to be upgraded to make it comply with the specified requirements.
You should also check with the local fire authority, usually the County Council, to see what 'on-going' fire precautions legislation will apply when the building is in use.