Permitted development rights (PD) are a national grant of planning permission set out in the General Permitted Development Order (GPDO). They let homeowners carry out many common projects — extensions, loft conversions, outbuildings — without making a planning application, provided the work stays within defined limits.
What permitted development covers
- Class A — enlargements, including single and two-storey rear extensions within size and siting limits.
- Class B and C — roof alterations and loft conversions (dormers), subject to volume limits of 40m³ for terraced houses and 50m³ for detached and semi-detached, and rules on materials and positioning.
- Class E — outbuildings such as garden offices, sheds and garages, within height and coverage limits.
- Other classes cover porches, hard surfaces, satellite dishes and more.
The limits that matter most
PD is generous but precise. Heights, depths, distances from boundaries, roof volumes, the 50% land-coverage rule and the "no extending forward of the principal elevation" rule all apply. Go a few centimetres over and the whole project can need planning permission.
When permitted development is restricted or removed
- Flats, maisonettes and listed buildings have little or no householder PD.
- Designated land — conservation areas, AONBs, National Parks and the Broads — has tighter limits.
- An Article 4 direction can remove specific PD rights for a street or area; check with your council.
Prove it with a certificate
PD rights don’t come with paperwork by default. A Lawful Development Certificate is the way to get formal confirmation from your council that your project is lawful. If you’re unsure whether you’re inside the limits, see our guide on whether you need planning permission for an extension.
Unformed’s Planning Review reads your drawings and checks them against the GPDO limits automatically — a fast way to know if you’re within permitted development before you build.
This guide is general information, not legal or planning advice. Planning rules change over time and are applied differently by each local planning authority (LPA). Always confirm the position with your council before starting work. Unformed’s Planning Review gives an AI-assisted risk assessment of a scheme but does not guarantee any planning outcome.