Planning permission

ENGLAND · PLANNING GUIDANCE

Planning permission

A garden room may be permitted development in England when it is incidental to the use of a house and all relevant conditions are met. A separate dwelling is not automatically covered.

It cannot be forward of the principal elevation of the original house. It must be single storey, with eaves no higher than 2.5 m. Overall height is limited to 4 m for a dual-pitched roof or 3 m for another roof.
Within 2 m of a boundary, the overall height cannot exceed 2.5 m. Buildings and additions cannot cover more than half the land around the original house.
Raised platforms above 30 cm are excluded from this outbuilding right. Different rules can apply to lower decking.
Listed buildings and designated areas have additional restrictions. These householder rights generally do not apply to flats or maisonettes.
An Article 4 Direction, a planning condition or certain changes of use can remove permitted development rights.

Ask your local planning authority about your site. A Lawful Development Certificate can provide formal confirmation. Planning permission and Building Regulations approval are separate requirements.

Planning Portal: outbuildings ↗