Permitted Development Rights Explained for London Homeowners
Permitted development (PD) rights allow homeowners to carry out certain types of building works without submitting a formal planning application. In theory, this speeds up and simplifies the process for minor works. In practice — particularly in London — the rules are layered with exceptions, restrictions, and area-specific controls that require careful checking.
What Can Be Done Under Permitted Development?
For a standard residential house (not a flat, listed building, or property in a conservation area with Article 4 directions), the main permitted development rights include:
Single-storey rear extensions:
- Up to 4m in depth for a detached house
- Up to 3m in depth for a semi-detached or terraced house
- Under the Householder Prior Approval route, these extend to 8m (detached) and 6m (others), subject to neighbour consultation
Loft conversions:
- Roof enlargements of up to 50m³ additional roof space (40m³ for terraced houses)
- Rear dormers and rooflights on rear roof slopes — within volume limits
- No change to the slope or height of the main roof at the front
Other works:
- Single-storey side extensions up to half the width of the original house
- Porches under 3m² floor area
- Outbuildings within certain size and height limits
What Is NOT Covered by Permitted Development in London?
Key restrictions that apply more broadly in London than elsewhere:
- Conservation areas: In designated conservation areas, many PD rights are removed or restricted — particularly side extensions, rear extensions visible from the highway, and cladding changes
- Article 4 directions: These are directions made by local authorities to remove PD rights in specific areas — common in many London boroughs, especially for HMO conversions and certain extension types
- Listed buildings: No PD rights for listed buildings — all works require listed building consent and planning permission
- Flats and maisonettes: Flats have no permitted development rights for extensions — all works require planning permission
The Prior Approval Route
Single-storey rear extensions beyond the standard PD limits (4m/3m) but within the larger limits (8m/6m for detached, 6m/4m for others) can be considered under the Householder Prior Approval (also called the Larger Home Extension) scheme. This involves:
- A formal application to the council
- Neighbour consultation (26 days)
- The council determining whether the extension would have "unacceptable impacts" on neighbours
Prior approval is not automatic and can be refused.
Lawful Development Certificates
Where you believe your works fall within permitted development, it is good practice (and sometimes essential for sale purposes) to obtain a Lawful Development Certificate (LDC) from the local planning authority confirming that the works are lawful. This is particularly important if you intend to sell the property within the next decade.
RCB Design & Build
RCB Design & Build reviews PD rights as standard at the start of every project — advising clients on what can be built without a planning application, what requires prior approval, and what requires a full application.