Permitted Development Rights are the biggest shortcut in English domestic planning. Build within the limits and you skip an 8-10 week planning determination entirely. Here is a plain-English guide to what Permitted Development still allows in 2026, with the specific size limits you need to know.
What is Permitted Development?
PD rights are set out in the Town and Country Planning (General Permitted Development) Order 2015, as amended. They allow certain extensions and alterations to a dwellinghouse without a full planning application, provided the works stay within strict limits.
Single-storey rear extensions
- Detached houses: up to 4m rear projection as standard, up to 8m under the Larger Home Extension prior approval route
- Semi-detached and terraced: up to 3m rear projection as standard, up to 6m under prior approval
- Maximum height: 4m from original ground to ridge
- Maximum eaves height: 3m where within 2m of a boundary
Two-storey rear extensions
- Must not project more than 3m from the original rear wall
- Must be at least 7m from the rear boundary
- The ridge and eaves must not exceed the host roof
- Pitch to match the host as far as practicable
- Obscure-glazed and non-opening (below 1.7m) windows on side elevations
What rules out PD?
- Flats and maisonettes. PD rights apply only to houses.
- Listed buildings. Any works usually need listed building consent.
- Article 4 directions. Local councils can remove PD rights in specific areas (common in conservation areas including parts of Edgbaston and Moseley). Check your council’s online map.
- Previous extensions. Earlier extensions count against your PD allowance.
- Material changes. Cladding or render on the front elevation generally needs planning.
Lawful Development Certificate
Even when a project is PD, we strongly recommend applying for a Lawful Development Certificate from the council before starting. It costs about half a planning fee, confirms in writing that your works are PD, and makes future sale conveyancing much simpler. We prepare the application as part of our standard service.
Prior approval for the larger extension
If you want a 6m rear extension on a semi (double the standard 3m) you can apply under the Larger Home Extension prior approval procedure. The council has 42 days to raise objections. If no neighbour objects, consent is automatic. We handle this process regularly.
Still need help?
Call CK Construction on 01527 521835 or use the contact form. We will tell you honestly at the first visit whether your project falls under PD or needs full planning.