Kitchen Extensions Deptford

A kitchen extension in Deptford is a job for the houses, and houses are the smaller part of the stock: 85% of homes here are flats and 15% are houses, with 14% terraced. On a terrace the choice is between a single storey rear extension and a side return infill that opens the back of the house into one kitchen and dining room. We build the shell, the steel into the house, the drainage and the kitchen itself as one programme, to the drawings you or your designer have had approved.

In Deptford, 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 Deptford: 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 Deptford terrace can take at the back

The depth a Deptford terrace can take at the back is set by guidance as much as by the plot, and Lewisham's Alterations and Extensions SPD, adopted on 24 April 2019, sets the frame. It says rear extensions on terraced or semi-detached properties should generally be no more than 3m deep. It also says an extension should never take up more than half the depth of the original rear garden or yard. Where the yard is short, the half depth rule becomes the limit before the 3m guide does.

For your kitchen this decides the layout early. If the yard only allows a shallow addition, a side return infill that widens the back room often gives more usable kitchen than extra depth. We measure the yard and the side passage on the first visit so that the layout you choose fits the guidance before any cabinets are drawn. That avoids redesigning the kitchen after the drawings have gone in.

Housing in Deptford

Deptford's housing, as the Council Tax list records it, is about 14,290 homes: 15% houses, 85% flats, with 9% pre-1919, 4% interwar and 84% built since 1945. Most homes here are flats, and only a ground floor flat in Deptford with its own garden can extend its kitchen.

Boundary walls, roof lights and glazing on a Deptford extension

On a Deptford rear extension the wall on the boundary governs the room. Lewisham's SPD says extensions up to 3m long should generally be no more than 3m high on the boundary, which caps the eaves on the neighbour's side, so the ceiling inside slopes or steps. A new wall on the line of junction, or steel bearing in the party wall, is notifiable under the Party Wall Act, and the building owner serves the notices. Height over the island has to come from a roof that rises away from the boundary.

The same SPD says roof lights in the original roof should ideally be flush and never project more than 150mm above its slope. That guide bites where the kitchen sits under the original back addition roof and you want light through that slope. On the new extension roof we place low profile units over the worktop and the sink, where daylight matters most. We set upstands and flashings at the frame stage, and the glazing supplier measures from the built opening, not from the drawing.

Drains under the yard in Deptford and the build over agreement

On a Deptford terrace the drain run under the back yard can decide the programme before the kitchen does. Lewisham's building control guidance says you must apply for a build over agreement before any works if your home is within 3 metres of a public drain or 1 metre of a public lateral drain. Where Lewisham is your building control body, it uses a full plans application for any proposal to build above or within 3 metres of a drain or sewer.

For a terrace this means the drain survey comes first. We lift the inspection chamber cover, trace the run and share what we find with you and your designer, so the build over agreement with the sewerage company and the building control route are in hand before the foundation is dug. The kitchen sink, dishwasher and any new gully are planned into the same drainage layout, which keeps the kitchen plumbing from needing a second dig later.

Flats in Deptford and the kitchen that stays inside

Owners of Deptford flats cannot add a kitchen extension under permitted development, because householder permitted development rules for extensions apply to houses only and not to flats and maisonettes. With 85% of Deptford homes being flats, the realistic kitchen project for many owners is a rework within the existing walls. Opening the kitchen into the living room needs building control approval where the wall is load-bearing, and in a leasehold flat the landlord usually has to consent first.

Where a ground floor flat owner does want to build out, it needs planning permission and normally the freeholder's consent under the lease, and the drawings follow from those. We can then build it in the same way as a house extension. For an upper flat, the better value is usually a new kitchen layout, relocated services and better daylight from the windows you already have, and we price that as its own job rather than stretching the extension scope.

• Island units with power and waste run through the slab
• The kitchen itself fitted under the same contract as the build
• Party wall process explained, with drawings for your notices

VOA Council Tax stock of properties, March 2025, for Deptford North, Silwood & Pepys and New Cross & Deptford South. Counts rounded by the VOA.

Two or three things usually come up alongside kitchen extensions on a Deptford job: kitchen renovation in Deptford, kitchen extensions across Lewisham, fitting the kitchen itself, how building control inspects an extension, kitchen extensions anywhere in London and Kitchen-Diner Layout Ideas.

Trusted Kitchen Extensions in Deptford

You get one team for the extension and the kitchen, so there is no gap between the builder leaving and the fitter arriving. Our founder has more than thirty years of hands-on building experience and runs the job from the first survey. The structural engineer we appoint sizes the steel, a registered electrician certifies the wiring and an engineer on the Gas Safe Register handles any gas. You get a written quotation after a site visit and a written programme you can plan your household around.

• Our own trades on site rather than a chain of subcontractors
• Screed left to dry before the kitchen floor finish goes down
• Old kitchen kept in use until the new shell is weathertight

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.