Yes, but you will need to obtain planning permission. Converting a detached garage into a self-contained living space, such as annexe, studio flat, or retail unit, represents a material change of use, particularly if it will function independently from the main house. This is because the garage would no longer be used in connection with the main dwelling and would effectively become a separate residential unit.

There is no single legal definition of "habitable room", as its use and meaning are subject to context. Generally, a habitable room is a space in a building that is designed for people to live, sleep, or spend extended periods of time in, but does not include bath or toilet facilities, corridors or utility rooms.

The green belt is a specially designated area of countryside protected from most forms of development. It is protected to help stop urban sprawl, preserve the character of existing settlements and encourage development within existing built-up areas.

The government are working on improving access to public land records, allowing you to check certain restrictions on land. You can view their progress here and see whether your land is greenbelt (note: this tool is currently under development).

You should contact your local planning authority to find out if your land is in a green belt area, and any policies or restrictions that may apply as a result.

‍

In many circumstances, rules known as ‘permitted development’ rights allow you to extend a house without needing to apply for planning permission, providing specific limitations and conditions are met. If you want to exceed these limits and conditions, then it is likely that an application for householder planning permission will be required.

The limits and conditions for building an extension under permitted development rules are covered in our guidance on the Planning Portal, and there are other points to take into consideration.

Visit Planning Portal to find out more.

‍

In many circumstances, rules known as ‘permitted development’ rights allow you to extend a house without needing to apply for planning permission, providing specific limitations and conditions are met. If you want to exceed these limits and conditions, then it is likely that an application for householder planning permission will be required.

‍

You can find information about the limits and conditions, prior approval and the building regulations on the Planning Portal by using the links below.  

Read about planning permission for extensions

Read about prior approval for larger single storey extensions

Find out about building regulations for an extension

‍