Planning permission for a garage conversion is not usually required, providing the work is internal and does not involve enlarging the garage structure (footprint).
If you intend to extend the garage structure as part of your garage conversion, a planning application may be required. Always contact your local Council's planning office before starting the garage conversion. Let them know you’re intending to convert the garage and ask to see if you need planning permission.
They should contact you back within several days letting you know if you would need to apply for a planning application or not. Usually, garage conversions can be undertaken within
permitted development rights so you won’t need to apply for planning permission.
However, sometimes permitted development rights have been removed from some properties with regard to garage conversions and therefore you should contact your local Council before proceeding, particularly if you live in a new housing development, in a conservation area or in a listed building. Where work is proposed to a listed building, listed building consent may also be required.
If you don’t live in a conservation area or a listed building you will more than likely not require planning permission to undertake a garage conversion.
However, if you do live within a conservation area or a listed building you may have to jump through a few hoops before you’re able to start the garage conversion.
Further guidance and information can be found on the Planning Portal link below.