Kitchen Extensions Greenwich

A kitchen extension in Greenwich starts with what the house is. Terraced houses are 31% of the borough's homes and semi-detached or detached houses 13%, so the usual shapes are a side return infill or a rear box. Royal Greenwich's Urban Design Guide sets out how deep a single-storey rear projection typically goes and how wide a side extension should be, and those two lines fix the room before any kitchen layout is drawn. We build the shell, the steel, the drainage and the fitted kitchen as one programme.

In Greenwich, 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 Greenwich: 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.

How deep a Greenwich rear kitchen extension can go

Royal Greenwich's Urban Design Guide says a 3.6m single-storey rear projection is typically considered appropriate, with more considered where neighbour amenity is not compromised. That figure is the working depth for a planning application here, and it is worth designing to it first. A kitchen that needs a deeper room to fit an island and a dining table is a different conversation with the planning officer, and the drawings should show the neighbour's windows and garden to make the amenity case.

Separately, national permitted development allows three metres beyond the original rear wall of a house that is not detached, and four metres for a detached house. So on a Greenwich terrace the lawful development route and the borough's design guide give different depths. The permitted development route is not open everywhere: at the listed addresses in the Rectory Field Conservation Area, an Article 4 direction means a side or rear extension needs planning permission. Your designer picks the route, and we set out the footings, the steel bearings and the floor level to the drawings that route produces, so the kitchen plan inside matches what was approved.

Housing in Greenwich

Roughly 125,080 dwellings sit on the valuation list for Greenwich. 45% are houses and 55% flats, and by age 22% predate 1919, 17% are interwar and 60% post-war. Since most homes here are flats, only a ground floor flat in Greenwich with its own garden can extend its kitchen.

Side returns and side extensions in Greenwich under the 50% guide

Royal Greenwich's Urban Design Guide says side extensions should typically be no more than 50% of the width of the original house. On a terrace the side return is the narrow strip beside the back addition, so an infill usually sits well inside that line. On a semi, a side kitchen that runs past the flank wall is where the guide bites, and the width of the new galley or utility strip is set by it.

In a Greenwich conservation area, the guide says planning permission is generally needed for all side extensions, including side infills to L-shaped houses. That covers the classic side return on a period terrace. Budget the time for an application even where the infill is modest, and let the design settle the glazing and the roof line first, because a change of rooflight or slope after consent can mean a fresh application.

Drains under the new Greenwich kitchen floor

Royal Greenwich requires a full plans application to build over or within three metres of a public sewer. A rear garden behind a terrace can carry a shared run that serves the row, so the first site job on a Greenwich kitchen extension is a drainage survey. If the run falls inside that distance, the building notice route is closed, full plans have to be deposited, and the water company's consent to build over or near the sewer is needed as well. Both move the start date.

The new kitchen also moves the sink, the dishwasher and often a new cloakroom, so the waste runs are designed with the footings, not after them. We lay the new connections, manholes and any diversion before the slab goes down, and we keep the falls to suit the island or sink position on the kitchen drawing. Getting that order right avoids breaking a finished floor to reroute a pipe, and it lets building control inspect the drains while they are still open.

Opening the back of the house and signing off in Greenwich

Where Royal Greenwich is the building control body and an extension opens up an existing elevation into an open-plan layout, it adds half the floor area of the adjacent rooms to the chargeable area. Knocking the old kitchen and back reception into the new room is exactly that, so the building control charge is set by the whole open space and not only the new footprint. Describe the full open-plan layout, with the rooms being opened up, when you or your agent apply, so the charge is right first time.

At the end, Royal Greenwich may need an electrical installation certificate, fire alarm commissioning certificate, gas certificate and double-glazing specification before completion for a domestic extension. The registered electrician issues the first, an engineer on the Gas Safe Register covers any hob or boiler move, and we collect the glazing specification from the supplier as the doors and rooflights arrive. Keeping those papers together from the start means the completion certificate is not held up by one missing sheet.

• Sliding, bifold and steel-framed glazed doors to the garden
• Kitchen-diner layouts planned before the foundations
• Rear, side return and wraparound kitchen extensions

VOA Council Tax stock of properties, March 2025, for all 35 statistical areas in Greenwich. Counts rounded by the VOA.

Once the kitchen extensions work in Greenwich is scoped, people usually go on to read kitchen renovation in Greenwich, our Greenwich area guide, a side return kitchen infill, the Party Wall Act on a boundary build, kitchen extensions anywhere in London and Permitted Development Explained.

Why Greenwich Homeowners Choose GS Renovation

A kitchen extension joins two trades that are often run by separate firms: the structure and the kitchen. We run both in one programme, so the steel, the drainage, the floor build-up and the rooflights are set out for the kitchen that will go in. The structural engineer we appoint designs the steel, your designer handles the drawings and any application, and we build to them. You deal with one site manager from the survey of the drains to the last worktop.

• Rated 4.9 from 31 reviews on MyBuilder
• Screed left to dry before the kitchen floor finish goes down
• Cooker extract taken outside through the new roof or flank wall, not recirculated

Reviewed jobs near Greenwich

1 MyBuilder review from Woolwich, with each customer's own job title:

• Replace kitchen extractor hob, Woolwich, 27 Apr 2024 (5 out of 5)

Read all 31 on our reviews page.

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.