Kitchen Extensions Kensington and Chelsea

A kitchen extension in Kensington and Chelsea is a house job in a borough of flats. Only 14% of homes are terraced houses and 2% are semi-detached or detached, while 84% are flats. A flat has no householder permitted development rights, so any extension to one starts with a planning application and the freeholder's consent. We build to the drawings and whatever consent the address needs: excavation and drainage, the steel into the back wall, the roof and glazing, then the kitchen itself.

In Kensington and Chelsea, a rear kitchen extension of about 30 square metres typically costs £45,000 to £97,500 excluding VAT, or £60,000 to £100,000 for a side return (indicative London ranges, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Kensington and Chelsea: the structural engineer we appoint designs the foundations and steel, we build the room and fit the kitchen, and a registered electrician certifies the electrics.

Which kitchen extension fits a Kensington and Chelsea terrace

The shape that fits is set by the neighbours as much as by the house. Policy CL9 of the council's Consolidated Local Plan resists an extension that would push rearward beyond the existing general rear building line of neighbouring extensions. The borough has since adopted its New Local Plan Review, so your designer confirms the current policy wording for your address. Either way, the line of the next-door extensions is the first thing to measure, before anyone draws a depth, and we note where each rear wall stops.

Once that line is fixed, the choice is between filling the width at ground or lower ground level and going only as deep as the neighbours already have. A wider, shallower room often gives a better kitchen than a long thin one, because the island and the table both sit near the new glass. The depth you settle on then decides the span of the steel, the fall of the roof and how far the drainage has to run.

Housing in Kensington and Chelsea

About 89,280 homes are listed for Kensington and Chelsea, and the mix is 16% houses to 84% flats, with 26% built after 1945, 8% in 1919 to 1939 and 65% earlier. Where most homes are flats, only a ground floor flat in Kensington and Chelsea with its own garden can extend its kitchen.

Closet wing infills and the Kensington Conservation Area

In the Kensington Conservation Area, the gap between two rear closet wings is one place a lower ground floor kitchen can go. The Kensington Conservation Area Appraisal notes that this void has frequently been infilled at lower ground floor level with conservatory type extensions. That tells you the form already exists in this part of Kensington and Chelsea. It does not mean a new infill will be approved, since the appraisal is one of the documents your drawings are read against, so the design question is how the glass roof meets the two flank walls.

Building one means working between two existing walls that were never meant to carry a roof. The structural engineer we appoint checks each wall, and we form pockets or pads for the steel so the new roof bears where the calculations say. Glazing bars, lead flashings and the upstands against old brick are where these rooms leak if they are rushed, so that junction gets its own day in the programme.

Permitted development limits and conservation areas in Kensington and Chelsea

National permitted development allows a single-storey rear extension of up to three metres beyond the original rear wall of a terraced house, and no higher than four metres. Outside designated land, prior approval raises the depth to six metres for a terraced house, but that route is not available in a conservation area. The borough's plan says conservation areas cover more than 73 per cent of Kensington and Chelsea, so check your street first. A listed house also needs listed building consent for the work, whatever the planning position.

On designated land such as a conservation area, every side extension needs householder planning permission. That matters for a side return kitchen, which is a side extension in planning terms even when it looks like a rear one. We do not decide this for you; your designer or planning agent confirms the route and applies. We price and programme from whichever drawings come back approved. If the approval comes with conditions on materials, we build samples for sign-off first.

Avoiding the rear extension faults Kensington and Chelsea appraisals name

Two of the borough's appraisals single out poor rear extensions. The Ladbroke Conservation Area Appraisal lists poorly designed rear extensions among the negative features affecting communal gardens, and the Brompton Conservation Area Appraisal counts oversized rear extensions among the elements harming that area. In Kensington and Chelsea that is written guidance a planning officer can point to, so scale and materials carry real weight. We read the relevant appraisal before pricing.

For you, this means the brick, the roof edge and the glazing pattern are decided early and then held on site. We order facing brick against a sample panel, keep parapets and fascias as thin as the drawings show, and do not swap the specified rooflights for something cheaper mid-job. Where the house backs onto a communal garden, deliveries and spoil come through the house, which we plan in the logistics from day one.

• Boiler relocation and flue changes on the enclosed rear wall
• Island units with power and waste run through the slab
• Soil stack and gully rerouting beneath the new floor

VOA Council Tax stock of properties, March 2025, for all 21 statistical areas in Kensington and Chelsea. Counts rounded by the VOA.

If this is your first project in Kensington and Chelsea, these are worth a look: kitchen renovation in Kensington and Chelsea, our Kensington and Chelsea area guide, fitting the kitchen itself, sign-off by building control on a kitchen extension, how we handle kitchen extensions across London and Underfloor Heating Costs.

Why Choose GS Renovation in Kensington and Chelsea

We take a kitchen extension from the approved drawings to a working kitchen as one programme, so the groundworks, drainage, steel, roof, glazing, plastering, electrics by a registered electrician and the kitchen fit-out follow one sequence under one team. You get a written quotation after a site visit, a written programme, and one point of contact from the first dig to the final worktop. Our founder brings more than thirty years of hands-on building to each job.

• Cooker extract taken outside through the new roof or flank wall, not recirculated
• One point of contact from first survey to handover
• Building control and Part P certificates handed over together at the end

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.