Kitchen Extensions Kensington

A kitchen extension in Kensington means a compact room at the back of a terraced house or work to a flat, since 13% of homes here are terraces and only 2% are semi-detached or detached. The rest are flats, which have no householder permitted development rights, so any extension to a flat goes through planning. We build the extension and the kitchen inside it as one programme, working to the drawings and consent you hold, with the structural engineer we appoint designing the steel.

In Kensington, 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: 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.

What a Kensington terrace can take at the back

On a Kensington terrace with rear closet wings, the kitchen extension that follows the existing pattern is a lower ground floor infill between the wings rather than a long box into the garden. The Kensington Conservation Area Appraisal notes that the void between rear closet wings has frequently been infilled at lower ground floor level with conservatory type extensions. That precedent shows the kind of room that already sits on these houses: glazed, set low, and held between two existing brick returns.

For the build it means a narrow site with party walls close on both sides, access through the house or down the area steps, and a floor that can sit below the garden. We plan the dig, the new slab and the damp proofing around that level change first, because the kitchen layout, the drain runs and the threshold into the garden all follow from it. If the design digs down to form a new or deeper room, that is basement development. A borough-wide Article 4 direction made on 15 April 2015 removed its permitted development rights, and a Construction Method Statement goes with any application. Glazing goes in late, once the structure is dry and square.

Housing in Kensington

On the valuation list Kensington counts about 9,000 homes, 85% flats and 15% houses; 75% predate 1919, 6% are interwar and 19% post-war. Since most homes here are flats, only a ground floor flat in Kensington with its own garden can extend its kitchen.

The rear building line rule in Kensington

The depth of a Kensington kitchen extension is set by your neighbours as much as by your plans. Policy CL9 of the Consolidated Local Plan resists an extension that would extend rearward beyond the existing general rear building line of any neighbouring extensions. Before your designer draws the room, it pays to walk the rear of the terrace, look over the garden walls and note where each existing back wall stops, since that line is the one the application will be judged against.

That line then governs everything we price: the length of steel, the number of roof lights, the run of worktop along the side wall and whether an island fits at all. A shallower room pushes the design towards a galley or an L along the party wall, with tall units kept in the original house. We work to the approved depth exactly, because a few hundred millimetres past the line is the kind of change that can bring an enforcement complaint from next door.

Planning routes for a Kensington kitchen extension

In Kensington the permitted development route is narrower than people expect, because conservation areas cover more than 73 per cent of the borough and flats have no householder rights at all. On Article 2(3) designated land, such as a conservation area, all side extensions need householder planning permission. That covers the side return, the usual kitchen widening on a London terrace, so the design, the drawings and the consent come before any price can be firm. A modest single-storey rear extension can still be permitted development in a conservation area, unless a direction removes it.

Householder permitted development rules for extensions also apply to houses only, not to flats and maisonettes. A garden flat owner in Kensington who wants a kitchen extension into the garden is therefore making a planning application from the start, and will normally need the freeholder's consent under the lease as well. With over 4,000 listed buildings in the borough, check the listing too: listed building consent is a separate application. We can start pricing and sequencing from your designer's drawings while the applications run.

Steel, drainage and glass in a Kensington period house

Opening the back of a Kensington period house into a new kitchen means taking load off brickwork that has carried it since the house was built. With 75% of homes here built before 1919, expect a solid brick rear wall, possibly with timber lintels and shallow footings, until opening up shows otherwise. The structural engineer we appoint specifies the beams and padstones, and building control inspects the steel and foundations before they are covered.

Drainage is the other early question. A lower ground floor kitchen can sit below the existing drain, so the sink and dishwasher may need a pumped outlet or a new connection lower down, agreed with building control. Roof lights and large rear glazing are ordered from measured openings after the steel is in, since period brick is rarely square. The kitchen units, worktops and appliances then follow in the same programme, with the electrics tested and certified by a registered electrician.

• Building control inspections from footings to completion
• Airbrick ducts to keep existing timber floors ventilated
• Flat roofs with rooflights or a roof lantern over the kitchen

VOA Council Tax stock of properties, March 2025, for Kensington Abingdon and Kensington Gardens. Counts rounded by the VOA.

Useful next reading for a kitchen extensions project in Kensington: kitchen renovation in Kensington, kitchen extensions across Kensington and Chelsea, a side return kitchen infill, sign-off by building control on a kitchen extension, kitchen extensions anywhere in London and Permitted Development Explained.

Trusted Kitchen Extensions in Kensington

We run the extension and the kitchen as one job, so there is a single programme from the first dig to the last worktop joint and no gap between two contractors. You hold the drawings and the consent; we build to them, raise questions early when a detail on site does not match, and keep building control inspections in step with the work. The structural engineer we appoint handles the steel design, and a registered electrician certifies the new circuits.

• One point of contact on the phone, not a call centre
• Old kitchen kept in use until the new shell is weathertight
• Drains surveyed by camera before the footprint is fixed

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.