Kitchen Extensions Eltham

Eltham's housing leans to the interwar years: 52% of homes here were built between 1919 and 1939, and 39% are semi-detached or detached. On an interwar semi the original kitchen is small and the garden behind it gives room to build, so the choice is between a straight rear extension and a wraparound. Terraced houses with a back addition take a side return. We build the structure, the steel back into the house and the new kitchen as one SE9 programme.

In Eltham, 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 Eltham: 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 depth Royal Greenwich accepts behind an Eltham semi

A 3.6m single-storey rear projection is the figure Royal Greenwich's Urban Design Guide treats as typically appropriate, and more can be considered where the neighbours' amenity holds up. On an Eltham semi the attached neighbour is usually the one whose light is most affected, so the depth on that side is the number your designer has to justify. The open flank has more room, so an L-shaped plan that is deeper away from the party wall can suit an interwar semi.

Permitted development gives a different baseline. A semi counts as any other house, so the national limit for a single-storey rear extension without an application is three metres beyond the original rear wall. Outside designated land, prior approval can take a semi to six metres; past that, or where the rights are restricted, it is a householder application to Royal Greenwich. We wait for the approved drawing before setting out, because the depth decides how long the foundation trench runs and which way the new floor drains.

Housing in Eltham

Roughly 14,360 dwellings sit on the valuation list for Eltham. 73% are houses and 27% flats, and by age 17% predate 1919, 52% are interwar and 30% post-war. 35% of homes here are semi-detached; a semi in Eltham can take its kitchen extension across the back and round into the side passage, which leaves room for a utility behind the kitchen.

Wraparounds and side infills on interwar SE9 houses

A wraparound on an Eltham semi is limited by width before depth. Royal Greenwich's guide says a side extension should typically be no more than 50% of the width of the original house, so the side element is normally a narrow band along the flank rather than a fill to the boundary. That narrow band is often enough for a utility room, a downstairs WC or a run of tall units, with the open kitchen sitting across the back.

A terraced house with a back addition takes a side return instead. The strip of yard beside the back addition is roofed and glazed, and the rear wall of the house is opened into it. The guide also says the council generally does not back new terraces or balconies on the flat roof of an extension. So the roof over any of these layouts is planned as a roof: roof lights, a parapet and a drained outlet, with no door onto it from above.

Conservation areas and the Progress Estate cottages

Designated land changes the route before any design is fixed. Eltham Palace Conservation Area was designated in 1971, with a character appraisal adopted in January 2008, and Eltham Green Conservation Area followed in 1975. On designated land every side extension needs householder planning permission under the national rules. Royal Greenwich's guide goes further and says permission is generally needed for all side extensions in its conservation areas, including side infills to L-shaped houses.

Eltham's Arts and Crafts estate cottages carry their own control. The Progress Estate was granted Article 4 Direction status by the Department of the Environment in 1973, and Royal Greenwich says Article 4 areas have less permitted development, so permission may be needed for most works. For a cottage there, treat the kitchen extension as a planned application from the outset, and expect the brick, roof tiles and window pattern to be matched rather than chosen.

Sewers, open-plan charging and the completion paperwork

Check the public sewer before the drawings go to building control. Royal Greenwich requires a full plans application to build over or within three metres of a public sewer, and behind a pair of Eltham semis a shared run can cross the back of the plot. Where the sewer is close, the foundations may need to bridge it, which the structural engineer we appoint details, and the water company's consent to build over or near its sewer is needed as well.

Opening the back of the house changes the building control sum as well. Where an extension opens an existing elevation into an open-plan layout, Royal Greenwich adds half the floor area of the adjacent rooms to the chargeable area. Near the end, Royal Greenwich may ask for an electrical installation certificate, fire alarm commissioning certificate, gas certificate and the double-glazing specification. We collect those from the registered electrician, the Gas Safe engineer and the glazing supplier as each trade finishes.

• New kitchen circuits, with Part P certification from a registered electrician
• Flat roofs with rooflights or a roof lantern over the kitchen
• Kitchen-diner layouts planned before the foundations

VOA Council Tax stock of properties, March 2025, for all 5 statistical areas in Eltham. Counts rounded by the VOA.

Useful next reading for a kitchen extensions project in Eltham: kitchen renovation in Eltham, kitchen extensions across Greenwich, a wraparound kitchen-diner, sign-off by building control on a kitchen extension, our London kitchen extensions page and Renovating a Victorian Terrace.

Why Eltham Homeowners Choose GS Renovation

An Eltham kitchen extension involves groundworks, steel, a roof, glazing, drainage and then a kitchen, and each trade depends on the one before. We run all of it as one programme with one site lead, so the kitchen layout is settled before the drainage is laid and the roof light positions match the ceiling plan. The structural engineer we appoint designs the steel, we build to your approved drawings, and you receive the certificates building control asks for at the end.

• Rooflights set out against the engineer's steel layout
• Paperwork and certificates handed over for when you sell
• 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.