Kitchen Extensions Borough

A kitchen extension in Borough starts from an unusual stock: the VOA counts 94% of homes here as flats and 6% as houses, with 0% semi-detached or detached. The houses that can take an extension are therefore terraces, and the job to plan for is a single storey rear or side addition that brings the kitchen out into the yard. We build the shell, the steel and the kitchen as one programme.

In Borough, 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 Borough: 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.

A flat in Borough cannot extend under permitted development

If you own a flat in Borough, a kitchen extension always needs a planning application. National householder permitted development rules for extensions apply to houses only and not to flats and maisonettes. Southwark's Householder SPD says the same thing in its own words: a single storey rear extension without planning permission is not available to flats, maisonettes, homes in a Conservation Area or listed homes. So the question for a flat owner is not whether the extension is small enough, but whether the scheme can win consent on its merits.

For a ground floor flat with its own yard, that changes the order of the job. The drawings go to Southwark first, the freeholder's consent runs alongside, and we price the build only once the approved scheme is fixed. Where no extension is possible, the kitchen can still move into a larger room inside the flat, which needs no planning permission unless the building is listed, although new drainage or a structural opening still comes under building control. Either way, the lease decides what you may touch, so read it before paying for drawings.

Housing in Borough

Borough has around 12,140 homes on the Council Tax list: 73% post-war, 3% interwar and 18% predate 1919, with 94% flats and 6% houses. Only a ground floor flat in Borough with its own garden can extend its kitchen, which matters here because most homes are flats.

How far a Borough terrace can go at the back without planning

Outside a conservation area, Southwark's Householder SPD lets a terraced house in Borough extend to the rear without planning permission by up to 3m in depth, with a maximum height of 4m. Rear extensions must also not take up more than 50% of the total rear garden space. On a terrace with a small yard, the garden limit often bites before the depth limit does. A later outhouse or earlier extension already in the yard counts against the allowance, while an original back addition is part of the house the depth is measured from.

The national rules set the same outer marks: no more than three metres beyond the original rear wall for any house that is not detached, and a height cap of four metres. Measure the yard before choosing a design. A shallow, full width box with a roof light over the worktop can give a Borough kitchen more usable space than a deeper, narrow addition that eats the whole yard and leaves nowhere for bins or a bike. Going beyond those marks moves the job onto a planning application, or outside designated land onto the national prior approval route, and either one adds its own time to the programme.

Conservation areas around Borough change the materials and the drawings

Southwark's Liberty of the Mint Conservation Area lies broadly to the west and south of Borough Tube Station, so some Borough addresses sit on designated land. Southwark's Householder SPD says a single storey rear extension without planning permission is not available to homes in a Conservation Area, and under national permitted development rules all side extensions on designated land need householder planning permission. Check the address against Southwark's conservation area map before a designer draws anything, because that one fact sets the planning route for the whole project.

The material choice also narrows. Southwark's Householder SPD says UPVC will not be permitted in any of the borough's Conservation Areas, even to the rear of a property. For a kitchen extension that means timber or metal framed doors and roof lights, and brick chosen to sit with the existing London stock. We order those items once the consent names them, because long lead times on metal glazing set the date the kitchen can be fitted.

Steel, drains and the kitchen fit in one Borough programme

Opening the back of a Borough terrace into the new room needs steel, and a structural engineer we appoint sizes it before the building control application goes in. Southwark's online form offers a building notice or full plans for new work, with regularisation kept for work already done. For an extension carrying a new beam, full plans gives you approved drawings before the old wall comes down. The inspector then visits at set stages, including the foundations and the steel, and the completion certificate follows the final visit.

Drainage comes next. A kitchen moving into the new room usually brings the sink and dishwasher to a new wall, and on a tight terrace the run to the existing gully or manhole decides where they go. We set the waste falls, underfloor heating and electrics before the screed, with a registered electrician certifying the new circuits, then plaster and fit the units and worktops ourselves, so one team carries the job from footings to the finished kitchen.

• Boiler relocation and flue changes on the enclosed rear wall
• Cooker hood extraction ducted through the roof or flank wall
• Flat roofs with rooflights or a roof lantern over the kitchen

VOA Council Tax stock of properties, March 2025, for Borough & Southwark Street and Southwark St George's. Counts rounded by the VOA.

Plenty of Borough projects start with one job and grow, so it helps to see kitchen renovation in Borough, kitchen extensions across Southwark, fitting the kitchen itself, the Party Wall Act on a boundary build, how we handle kitchen extensions across London and Extend or Move?.

Why Choose GS Renovation in Borough

A kitchen extension on a small terrace joins two trades that are usually hired separately: the builder who opens the back of the house and the fitter who installs the kitchen. We do both, so the programme has one start, one sequence and one person answerable for it. You get a written quotation after a site visit, and drawings and a written programme to share with your designer and neighbours. The firm is founder-led, so you have one point of contact from the quotation to handover.

• One contract for the groundworks, the steel and the kitchen fit
• New floor level matched to the existing house, with no step at the opening
• Our own trades on site rather than a chain of subcontractors

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.