Planning permission is not usually required for a garage conversion, providing the work is internal and does not involve enlarging the building. Around 20% of garage conversions will require planning permission.
If your intention is to convert a garage into a separate house (regardless of who will occupy it), then planning permission may be required no matter what work is involved. We advise that you discuss such proposals with your local planning authority to ensure that any work you do is lawful and correctly permissioned.
Sometimes permitted development rights have been removed from some properties with regard to garage conversions and therefore you should contact your local planning authority before proceeding, particularly if you live on a New Housing Development or in a Conservation Area.
Where work is proposed to a listed building, listed building consent may be required.
Please note: The permitted development allowances described here apply to houses and not to:
Flats and maisonettes (view our guidance on flats and maisonettes)
Converted houses or houses created through the ‘permitted development’ rights for:
‘Changes of use’ (Schedule 2, Part 3, Classes M; N; P; PA and Q) (as detailed in our change of use section).
‘New Dwellinghouses’ (Schedule 2, Part 20)
Areas where there may be a planning condition, Article 4 Direction or other restriction that limits permitted development rights.
Source: Planning Portal
But please don't worry if you don't understand the above conditions list, we will make inquiries on your behalf to find out if your garage conversion needs planning permission.
Planning Application Cost
A standard householder planning permission application costs £206.00 (As of 1st January 2021).
Source: Planning Portal Fee Calculator