Rear extension in Kensington and Chelsea

Almost always, yes. Conservation areas cover most of Kensington and Chelsea, and even where the basic single-storey rear allowance would normally survive conservation-area status elsewhere in London, the borough's dozens of property-specific Article 4 directions frequently remove it on a house-by-house basis. Treat a full householder application as the default and confirm the position for your specific address before you commission drawings — two houses on the same terrace can have different permitted development rights.

Conservation coverage and Article 4 directions make a full householder application the default; matching stock brick and lime mortar are expected.

Rear extensions are the most routine project on London's terraced stock, but Kensington and Chelsea applies unusually exacting design scrutiny even to a straightforward single-storey scheme. The borough's period terraces are built in stock brick and stucco, and officers expect new brickwork and pointing to match the host building closely — lime mortar rather than a modern cement mix is a standard expectation here, not an optional upgrade. Because such a large share of the borough's houses are also listed, a rear extension often needs listed building consent running alongside the planning application: a second consent process, with its own drawings and heritage justification, that most other London boroughs don't require for what is otherwise a routine project.

Permitted development (GPDO Class A) covers single-storey rear extensions up to 3m beyond the original rear wall on attached houses and 4m on detached, with a maximum height of 4m. The 'larger home extension' route extends this to 6m/8m through prior approval with neighbour consultation — but that larger route is not available in conservation areas.

In conservation areas, the basic 3m/4m single-storey rear PD allowance usually survives — what conservation-area status removes is side extensions and two-storey rear extensions. An Article 4 direction can remove more, but Camden's directions in Hampstead and Belsize target front-and-side appearance (solar panels, window changes, boundary treatments), not the single-storey rear allowance. Flats have no PD rights at all. Two-storey rear extensions in conservation areas always need full permission.

Practical rule across London: check the address first. If a conservation area or Article 4 direction applies, budget for a full householder application decided on design, neighbour daylight (the 45-degree test) and materials.