Do I need Planning Permission for a single storey rear extension?

Whether you need planning permission for a single-storey extension depends on several factors, such as the location, size of the extension, and specific conditions set by your local council. Many single-storey extensions fall under permitted development rights, which allow certain types of work to be carried out without planning permission if they meet specific criteria.

Permitted Development Rights

Single-storey extensions can often be built without planning permission if they adhere to the following guidelines:

1. The extension must not extend more than 3 metres from the original rear wall for attached houses or 4 metres for detached houses.  If the extension is larger (up to 6 metres for attached houses or 8 metres for detached houses), a prior approval application is necessary.
2. The maximum height of the extension should not exceed 4 metres. The height of the eaves should not exceed the eaves of the existing house and must be no more than 3 metres if within 2 metres of the boundary.
3. The extension should not be built forward of the principal elevation or a side elevation that faces a highway. It must be at least 2 metres away from the boundary if it exceeds 4 metres in height.
4. The materials used must match the appearance of the existing house to ensure visual consistency.
5. In special areas such as conservation areas, Article 4 designations, there are additional restrictions, and some permitted development rights might not apply.