Permitted development,explained

A planning permission you already have

The Town and Country Planning (General Permitted Development) (England) Order 2015 — the GPDO — grants planning permission in advance for defined kinds of work. For houses, the rules are in Schedule 2, Part 1, split into classes: Class A for extensions, Class B for roof enlargements, Class D for porches, Class E for outbuildings, and so on.

Each class sets limits — depth, height, volume, distance from boundaries. Stay within every limit and the work is lawful without an application. Break any one of them and the whole project needs planning permission, not just the part that's over.

Who has permitted development rights

Most houses in England do. Flats and maisonettes don't — householder rights apply only to dwellinghouses. Houses created by a change of use (an office converted to homes under permitted development, for example) also don't.

• —Listed buildings: most classes still exist, but listed building consent is needed for almost any work, and some classes are removed entirely.
• —Conservation areas, National Parks, National Landscapes and World Heritage Sites (“Article 2(3) land”): the rights are narrower — no side extensions, two-storey rear extensions, dormers or cladding.
• —Article 4 directions: a council can remove specific rights in a defined area.
• —Planning conditions: the permission for your house may have removed rights, especially on estates built since the 1980s.

Everything is measured from the original house

“Original” means the house as it stood on 1 July 1948, or as first built if later. Any extension added since — by you or a previous owner — uses up allowance. That's why two identical semis on the same street can have different answers.

Getting certainty

You don't have to tell anyone before building under permitted development (except for prior approval projects). But if you're spending serious money, or you'll sell within ten years, a Lawful Development Certificate from the council confirms the work was lawful — and it's what buyers' solicitors ask for.