Often not, but it depends. A detached garage in a house's garden can usually be built under permitted development if it is single storey, sits behind the front of the house, stays within the height limits and, together with other outbuildings, covers no more than half the garden. An attached garage is treated as an extension and follows those rules instead. Conservation areas, listed buildings, flats and some new estates have tighter controls. Building Regulations are a separate matter.
Detached garages as outbuildings
In planning terms, a detached garage in a house's garden is an outbuilding. Under permitted development, outbuildings must be single storey and used for purposes incidental to the house, which parking and storage are. They cannot be used as a separate home, and they must not sit forward of the principal elevation, which is usually the front wall facing the road.
The height limits
Height rules are where many garage designs need adjusting. The general limits are an eaves height of 2.5 metres, and a maximum overall height of 4 metres for a dual-pitched roof or 3 metres for other roofs. However, if any part of the garage is within 2 metres of a boundary, the whole building must be no taller than 2.5 metres. That is why many garages close to a fence line have flat or very low-pitched roofs.
- Single storey only
- Eaves no higher than 2.5 m
- Up to 4 m with a dual-pitched roof, 3 m otherwise
- No more than 2.5 m overall within 2 m of a boundary
- Not in front of the main front wall of the house
How much of the garden it can cover
Outbuildings, extensions and sheds together must not cover more than half of the land around the original house. Original means the house as first built, or as it stood in 1948, so earlier additions count against the allowance.
Attached garages follow extension rules
A garage joined to the house is not an outbuilding. It is assessed as a house extension, so the side and rear extension limits apply, including width and depth restrictions. Our extension planning permission guide explains those rules, and an attached garage is far more likely to need a full application, particularly if it sits beside the house facing the road.
When you will need permission
Permitted development does not apply everywhere. In conservation areas, outbuildings to the side of a house usually need permission. Listed buildings, flats and maisonettes have no outbuilding rights at all. Some estates, especially newer ones, had permitted development rights removed when they were approved, which you can check in the original planning conditions. A garage forward of the house always needs an application.
Building Regulations
Planning and Building Regulations are separate. A small detached garage under 30 square metres of floor space, built mostly of non-combustible materials or set at least one metre from boundaries, is often exempt. Attached garages generally need approval for structure, fire separation from the house and drainage. If in doubt, ask building control before work starts.
Confirming your position in Northamptonshire
Depending on your address, planning is handled by West Northamptonshire Council, which covers Northampton and Towcester, or North Northamptonshire Council, which covers Kettering and Wellingborough. A lawful development certificate gives written confirmation that a garage is permitted development, which is helpful when you sell. The national Planning Portal also has an interactive guide to outbuildings.
Building your garage
Superior Build & Landscape builds new garages for homeowners in Northampton and the surrounding area. Once you know which route applies, George can talk through size, roof and brickwork, and our garage cost guide explains what drives the price.
Frequently asked questions
Can I build a garage without planning permission?
Often yes, if it is a single storey detached garage behind the front of the house, within the height limits and covering no more than half the garden with other buildings.
How close to the boundary can a garage be?
It can be close, but within 2 metres of a boundary the whole building must be no more than 2.5 metres tall under permitted development.
Does an attached garage need planning permission?
It is treated as an extension, so it must meet extension rules. Many attached garages beside the house need a full application.
Do I need Building Regulations for a garage?
Small detached garages under 30 square metres often do not, but attached garages generally do. Check with building control.
Can I build a garage in front of my house?
Not under permitted development. A garage forward of the main front wall needs planning permission.