How Big Can a Garage Be Without Planning Permission

Building a garage is a popular way to create secure parking, increase storage and enhance the value of your home. In many cases across the UK, homeowners can build a garage without applying for planning permission, thanks to permitted development rights. However, there are specific size, height and location limits that must be followed. Understanding these rules is essential before starting your project, as going beyond them can lead to enforcement action or costly redesigns.

Permitted Development Rights for Garages

Permitted development rights allow you to carry out certain building work without needing to apply for full planning permission. These rights apply to houses only, not flats, maisonettes or listed buildings, and they can be restricted in certain locations such as conservation areas or new housing developments. If permitted development rights have been removed by an Article 4 Direction or a planning condition on your property, even small garages may require consent.

To qualify as permitted development, a garage must be a single-storey outbuilding used for purposes incidental to the enjoyment of the main dwelling. This includes parking, storage or hobbies, but not self-contained living accommodation or business use that attracts visitors or causes disruption.

Size and Height Limits Without Planning Permission

Under permitted development, a garage can be built without planning permission as long as it meets the following criteria. The maximum height allowed is four metres for a dual-pitched roof or three metres for other roof types. If the garage is located within two metres of any boundary, its height must not exceed 2.5 metres.

There is no strict maximum floor area stated in legislation, but the garage must not occupy more than fifty per cent of the total land around the original house. This calculation includes all outbuildings, extensions and other structures, so if you already have a garden room or shed, the space remaining for a garage may be limited. The garage must also be sited behind the principal elevation of the house and must not be placed forward of the front wall if it faces a road.

For most properties, these rules allow for a garage of around thirty square metres or less, depending on the layout of the garden and other development on the plot. A detached garage larger than thirty square metres may still be permitted development if it meets the height, use and location criteria, but it may also need to comply with Building Regulations.

Restrictions in Designated Areas

If your home is in a conservation area, national park, World Heritage Site or Area of Outstanding Natural Beauty, permitted development rights are more limited. You may not be able to build a garage to the side of the house, and even small structures at the rear could require consent. Listed buildings and properties with Article 4 Directions are usually excluded from permitted development altogether, meaning planning permission is almost always required.

Building Regulations and Compliance

Even if you do not need planning permission, your garage may still require Building Regulations approval. Detached garages under thirty square metres are usually exempt, provided they are built of non-combustible materials and are more than one metre from any boundary. If the garage is attached to the house, contains electrical wiring or is intended for more complex use, it will need to comply with Building Regulations to ensure safety, insulation and structural integrity.

Any electrical work must be carried out by a registered electrician under Part P of the Building Regulations. If plumbing or insulation is added with the intention of using the garage for more than storage or parking, you will need to consult with your local building control office.

Practical Examples

A homeowner in Newcastle built a detached garage at the rear of their semi-detached house. The structure was 2.4 metres high with a flat roof and measured 5.5 metres by 5 metres in footprint. It was located 2.1 metres from the boundary and took up less than forty per cent of the garden. Since it met all permitted development limits and was used only for parking and storage, no planning permission or building control approval was needed. Another resident in Berkshire planned a garage with a pitched roof measuring 4.5 metres high, close to a neighbour’s fence. Because it exceeded the height limit within two metres of the boundary, it required a full planning application, which was granted with conditions to protect neighbour amenity.

Certificates and Confirmation

If you want certainty that your garage is allowed under permitted development, you can apply for a Certificate of Lawful Development from your local authority. This is a legal document that confirms planning permission is not required and can be useful when selling your home or if the planning rules change in the future.

Conclusion

You can usually build a garage in the UK without planning permission if it meets the limits set by permitted development rights. The structure must be no taller than four metres, or 2.5 metres if near a boundary, and it must not take up more than fifty per cent of the land around the house. The garage must also be placed to the side or rear of the property and used for purposes incidental to the home. Planning permission may be required in conservation areas or where permitted development rights have been removed. It is always wise to check with your local planning office before starting any work.