The limits
| Where it sits | Max height | Max eaves |
|---|---|---|
| Within 2 m of a boundary | 2.5 m | 2.5 m |
| Further in — dual-pitched roof | 4 m | 2.5 m |
| Further in — any other roof | 3 m | 2.5 m |
| Front garden | Not permitted | Not permitted |
Other conditions
- Single storey only.
- Not forward of the front wall of the house.
- No verandas, balconies or raised platforms over 0.3 m.
- Together with extensions, no more than half the garden covered.
- Used for purposes incidental to the house — an office, gym or studio, not a bedroom or annexe.
When you can’t use permitted development
Flats & maisonettes
No householder permitted development rights at all.
Listed buildings
Not permitted development — planning permission and listed building consent.
Conservation areas
Nothing between the side of the house and the boundary. Otherwise the standard size limits apply.
Article 4 directions
Your council may have removed this right on your street.
Planning conditions
An old permission may have removed permitted development rights. Not published anywhere.
New builds
Often have permitted development removed by condition. Check your deeds.
Your exact limits
Every project for your house type, with Article 4, listing and trees checked at your address.
£17.99one-off
Get my reportWhat “incidental” means
Class E covers buildings used for something ancillary to living in the house: a home office, gym, studio, playroom, workshop or storage. Somewhere to sleep, with its own kitchen or bathroom, is a separate dwelling and needs planning permission regardless of size.
A toilet or sink for use with a gym or office is generally fine. A bedroom with en suite for a relative is not.
Garden room rules by council
Some councils have Article 4 directions that change these limits. Pick yours to see what applies locally.
Common questions
- Do I need planning permission for a garden room?
- Not usually. A garden room is an outbuilding under Class E permitted development: single storey, no higher than 2.5 m within 2 m of a boundary, behind the front of the house, and with other buildings covering no more than half the garden. You need planning permission if it breaks those limits, will be lived or slept in, or the house is a flat or listed building.
- Which outbuildings are permitted development?
- Sheds, summer houses, garden offices, gyms, studios, workshops, greenhouses, garages and swimming pools can all be permitted development under Class E, as long as they're used for something incidental to the house and meet the same height and garden-coverage limits.
- Can I put a garden room in a conservation area?
- Yes, but not between the side of the house and the boundary. Anywhere else in the back garden the normal size limits apply.
- Can I sleep in a garden room?
- Not under permitted development. Sleeping accommodation takes it outside Class E, so a garden bedroom or annexe needs planning permission.
- Does a garden room need building regulations?
- Often not, if it's under 15 m² with no sleeping accommodation, or under 30 m² and at least 1 m from a boundary or built of non-combustible materials. Check with building control if you're unsure.