Building work in Kensington and Chelsea: area guide

The Royal Borough of Kensington and Chelsea is the planning and building control authority for Kensington and Chelsea, which covers W8, SW3, SW5, SW7, SW10, W10, W11 and W14 and takes in Kensington, Chelsea, Notting Hill, South Kensington, Knightsbridge and Holland Park. This is our area guide to building work in the borough; for whole-house refurbishment go to Home renovation in Kensington and Chelsea.

For Kensington and Chelsea the Council Tax list gives about 89,280 homes; by type 84% flats and 16% houses, by age 26% post-war, 8% interwar and 65% older than 1919. VOA Council Tax stock of properties, March 2025, for all 21 statistical areas in Kensington and Chelsea. Counts rounded by the VOA.

Planning and building control in Kensington and Chelsea

What the Royal Borough of Kensington and Chelsea publishes about building work in the borough, with each point linked to the council page it comes from:

• The publication version of the New Local Plan Review states that conservation areas cover more than 73 per cent of the borough. planningconsult.rbkc.gov.uk
• The council made a borough-wide Article 4 direction on 15 April 2015 to remove permitted development rights in relation to basement development. planningconsult.rbkc.gov.uk
• The council's consultation page states it was proposed that the non-immediate basement Article 4 direction would come into force on 28 April 2016, subject to representations and confirmation. planningconsult.rbkc.gov.uk
• The publication version of the New Local Plan Review states there are over 4,000 listed buildings in the borough. planningconsult.rbkc.gov.uk
• The national Planning Data record for the council's New Local Plan Review, which it lists as adopted, gives the plan a start date of 2024-07-24. planning.data.gov.uk
• The council's Householders' Guide to windows, published with the draft Windows Local Development Order, states that building regulations apply to all replacement windows. planningconsult.rbkc.gov.uk
• The publication version of the New Local Plan Review saved the existing basements policy CL7, giving it the new policy reference CD 10. planningconsult.rbkc.gov.uk

With 84% of Kensington and Chelsea's homes flats, the lease comes first on many jobs. Flats have no householder permitted development, so an extension or most external changes to a flat need planning permission from the Royal Borough of Kensington and Chelsea as well as the freeholder's consent. The 16% that are houses keep the householder rights within the size limits, and in a conservation area a single-storey rear extension survives unless an Article 4 direction removes it. Taking out a wall or a chimney breast is building regulations work, not planning, unless the building is listed.

Kensington and Chelsea is small, dense and mostly designated: conservation areas cover nearly three quarters of it. Stucco townhouses in Kensington and Notting Hill, Georgian and Victorian houses off the King's Road, mews properties behind the main streets, and mansion flats through SW7 and SW3, which on VOA figures are the majority. Plots are narrow, gardens short and elevations protected, so schemes work downwards and inwards. Know what the fabric will take before anything is opened up, and in a flat that starts with the freeholder.

Designation rules most of this borough and pushes work inside

Conservation areas cover nearly three quarters of the Royal Borough. Inside them a side extension, a two-storey rear extension, a roof extension or cladding needs planning permission, and the council's Article 4 directions bring smaller changes such as windows, front doors, boundary walls and roof coverings under control as well, while a separate borough-wide direction covers basements. Most external changes need consent from the Royal Borough of Kensington and Chelsea first, and buying materials ahead of a decision is a false economy.

Inside, mansion flats are gated by freeholder consent for any structural change and, for a bathroom renovation, by the shared soil stack and the floor over the flat below. In houses, reordering a lower ground floor, joining front and rear reception rooms, or turning a dark rear return into a proper kitchen are achievable. Those openings usually mean an RSJ job: the engineer designs beam and bearings, and we build to it, needled and propped until the new support is loaded and packed.

Mews streets, basements and neighbours: party wall notice first

Basement and lower ground work is common across Chelsea and Holland Park because there is nowhere else to go. Excavating near a neighbour's foundations triggers the Party Wall etc. Act 1996, as does cutting RSJ bearings into a shared wall, so notice often comes with structural alterations here. The duty to serve it sits with you as the building owner, and notice periods go in the programme rather than being discovered halfway through.

Access shapes everything else. Mews streets around Knightsbridge and South Kensington are narrow, controlled and often gated, with no room for a skip and limited turning space for a lorry. We size deliveries to what the street can take, arrange skip permits or bagged removal in advance, and sequence work so you can keep living there while the messiest stages are boxed off and ventilated.

Popular starting points in Kensington and Chelsea: kitchen renovation in Kensington and Chelsea, house extensions across Kensington and Chelsea, builders in London and How to Choose a Builder.