What permitted development is
Permitted development rights are a national grant of planning permission for certain types of work, set out in the General Permitted Development Order 2015. If a project meets every limit and condition, you do not need to apply for planning permission. If it fails any one of them, the whole project needs permission.
Limits are measured against the original house, meaning the house as built or as it stood on 1 July 1948. Extensions added by previous owners count towards your allowance.
Rear extensions (Class A)
- Single storey: up to 4 m deep for a detached house, or 3 m for other houses, with a maximum height of 4 m.
- Larger home extension: up to 8 m (detached) or 6 m (other houses), through the neighbour consultation prior approval process. Not available on article 2(3) land such as conservation areas.
- Within 2 m of a boundary, eaves height is limited to 3 m.
- Two-storey or more: up to 3 m deep, and at least 7 m from the rear boundary.
Side extensions
Single storey only, up to 4 m high and no wider than half the width of the original house. Side extensions are not permitted development in conservation areas.
Loft conversions (Classes B and C)
- Additional roof volume of up to 40 m³ for terraced houses and 50 m³ for detached and semi-detached houses.
- No extension on a roof slope fronting a highway, and nothing higher than the existing ridge.
- Dormers set back at least 20 cm from the eaves, where practical.
- Side-facing windows must be obscure-glazed and non-opening below 1.7 m.
- Not permitted development in conservation areas.
Porches (Class D)
Up to 3 m² of ground floor area, no higher than 3 m, and at least 2 m from any boundary with a highway.
Outbuildings (Class E)
- Single storey, not forward of the principal elevation, and for purposes incidental to the house (not a separate home).
- Maximum height of 4 m for a dual-pitched roof or 3 m otherwise, or 2.5 m within 2 m of a boundary. Eaves no higher than 2.5 m.
- Together with extensions, buildings must not cover more than 50% of the land around the original house.
Materials and other rules
Materials for extensions must be similar in appearance to the existing house. Balconies, verandas and raised platforms over 0.3 m high are not permitted development. Other classes cover hardstanding, solar panels and heat pumps.
Our advice
Permitted development is detailed and easy to get wrong, and a council can take enforcement action if a project goes even slightly over the limits. Check the limits against your original house, confirm there is no Article 4 direction, and get a lawful development certificate before you build. It costs far less than putting things right afterwards.
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Sources
- GOV.UK: Permitted development rights for householders: technical guidance
- The Town and Country Planning (General Permitted Development) (England) Order 2015
- Planning Portal: common projects
This article is general information about planning in England at the date shown. It is not advice on any particular site, and the law and policy may have changed since. Please speak to us before relying on it.