Garages can be built in your garden or on the land around your house without the need to apply for planning permission.
However, permission will be required in certain circumstances. If you live in a listed building you should check with your Local Planning Authority.
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.
Learn more about building a garage on the Planning Portal
Learn about garage conversion on the Planning Portal.
Find a planning consultant.