Kitchen Extensions Streatham

For a Streatham house, a kitchen extension means filling the strip beside the back addition, squaring off the rear, or both. Terraced houses are 21% of the homes in Streatham and semi-detached or detached houses 12%, so the side return is a common starting point and a full-width rear room the next. Flats are 67% of homes, and a flat carries no householder permitted development rights, so any flat extension goes through planning. We build the shell, carry the house on steel and fit the kitchen as one job.

In Streatham, 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 Streatham: 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.

Side return, rear or wrap-around on a Streatham house

The shape of your back addition decides the extension. On an Edwardian terrace off Streatham High Road the return leaves a narrow passage along the boundary, and infilling it widens the kitchen by the width of that passage. Lambeth's Design Guide treats single storey infill, end and wrap-around extensions to rear returns as potentially acceptable where the new work stays subordinate to the house and does not harm the neighbours' amenity. Height and depth are therefore set with the next door windows in mind.

A wrap-around joins the infill to a new room across the full back, giving one open space from the old dining room to the garden. The guide accepts wrap-arounds in most circumstances but resists them on heritage assets and in conservation areas. Before you commission drawings, check whether your street falls inside a designated area, because that single question tells your designer whether to draw an L-shaped plan or keep to the side strip.

Housing in Streatham

Around 27,640 homes make up Streatham on the valuation list; 67% are flats and 33% houses, and 43% date from before 1919, 27% from between the wars and 29% from after 1945. Most homes here are flats, and only a ground floor flat in Streatham with its own garden can extend its kitchen.

Conservation areas and Article 4 around Streatham Common

Two Lambeth conservation areas carry Streatham's name, and they are not the only ones nearby. The Streatham Common conservation area (CA 43) was first designated on 16 June 1994, and the Streatham High Road and Streatham Hill conservation area (CA 54) on 7 December 1999, with boundary changes in January 2024. A house inside either boundary loses the permitted development route for side extensions, so a side return there needs householder planning permission. Check Lambeth's conservation area map for your address before any drawings are commissioned.

Lambeth also lists all or parts of the Streatham Lodge and Leigham Court Estate conservation areas as having Article 4 Directions on external alterations. A direction of that kind brings alterations that would otherwise be permitted development, such as replacement windows and doors, under planning control, so check which elevations it covers before you change the back wall. Lambeth says a householder application should get a response in 8 weeks, and we set the start date from the decision notice, not from the date the drawings go in.

How far a Streatham rear extension can go without planning

A Streatham house can often extend at the rear under permitted development. The national limit for a single storey rear extension is four metres beyond the original rear wall of a detached house and three metres for any other house, and the height cannot exceed four metres. For a Streatham terrace or semi that means three metres unless you go through prior approval. Check the designation of your street first, since in a conservation area the permitted route does not cover side extensions.

A listed building is the exception: work that affects its character, inside or out, including an extension or taking out a wall or chimney breast, needs listed building consent from Lambeth Council, and doing it without consent is a criminal offence.

Prior approval lifts the limit to eight metres for a detached house or six metres for any other house, but that larger route is not available on designated land such as a conservation area. The deeper the room, the more the middle of the kitchen depends on roof lights for daylight, so depth and glazing are decided together. We recommend a lawful development certificate before building, because a sale later will ask for proof that the extension was allowed, and we build to the dimensions on that paper.

Brick flank walls, glazing and the kitchen fit-out

On a Streatham infill, the wall on the boundary is generally built in brick with a parapet. Lambeth's Design Guide says party walls of infill and wrap-around extensions should generally be built in brick with parapets so no gutter overhangs the neighbour, which means a box gutter or an internal outlet on your side. That detail affects the drainage run and where the rainwater pipe comes down, so we fix it before the slab is poured.

The guide also asks for side infills to be mostly glazed to stay visually lightweight, and it normally limits glazed extensions to a single storey at ground or semi-basement level at the rear. A glazed side roof over the old passage brings light deep into the plan. Because we fit the kitchen in the same programme, the extract duct, the sink waste and the island supply are set out in the new floor before screeding, so nothing is chased in afterwards.

• Utility rooms and larders at the back of the extension
• Island units with power and waste run through the slab
• Kitchen-diner layouts planned before the foundations

VOA Council Tax stock of properties, March 2025, for all 7 statistical areas in Streatham. Counts rounded by the VOA.

Alongside kitchen extensions in Streatham, the pages that usually help next are kitchen renovation in Streatham, kitchen extensions across Lambeth, fitting the kitchen itself, the Party Wall Act on a boundary build, kitchen extensions across London and Steel-Framed Doors Guide.

The GS Renovation Difference in Streatham

You get one team from the dig to the worktops, so the steel, the drainage, the glazing and the kitchen units are sequenced on one programme rather than handed between trades. The structural engineer we appoint sizes the beams, a registered electrician certifies the circuits, and building control inspects the stages. We work from your approved drawings and tell you before the start what the neighbours need to know, so you, as the building owner, or a surveyor acting for you can serve any party wall notices in good time.

• Building control and Part P certificates handed over together at the end
• Paperwork and certificates handed over for when you sell
• 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.