Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Add paragraph text. Click “Edit Text” to update the font, size and more. To change and reuse text themes, go to Site Styles.
Kitchen extension cost · London & Hertfordshire
Kitchen extension cost in London 2026: the build, the fit-out, and the number in between
By Anderson & the LCCL Construction Team
Finchley N3 · Design & build, LABC award winners 2024 and 2026
A kitchen extension in London costs £35,000–£128,000 for the build in 2026 — rear, side return or wraparound — plus £15,000–£75,000 for the kitchen itself. Most cost guides quote one or the other; this page gives you both, by shape and by specification, so the figure you plan around is the figure you pay.
Quick answer
£35,000–£128,000 for the extension build plus £15,000–£75,000 for the kitchen fit-out, design and build inclusive. Postcode dependent.
Single-storey rear and side return kitchen extensions are usually permitted development; wraparounds and anything in a conservation or Article 4 area need a planning application.
10–16 weeks on site; 8–12 weeks of design and approvals before that.
A free 30-minute phone call with our team, no obligation.
LABC Building Excellence Award 2024
Best Residential Extension in London — Bohun Grove, East Barnet EN4
LABC Building Excellence Awards 2026
London Regional Winner, Best Conversion or Alteration — Weech Road NW6
One contract
Architecture, structural engineering, planning, construction and project management — all under one contract
Guaranteed & insured
12-month workmanship guarantee, structural guarantee to building-control sign-off, 10-year LABC Warranty available
How much does a kitchen extension cost in London in 2026?
Guide ranges by size, design and build inclusive. Every project is priced from your postcode and house type.
Extension shape
Typical use
Build range
Rear extension 3–6 m
Kitchen extended into a kitchen-diner with garden doors
£35,000 – £75,000
Side return infill
Galley kitchen widened to full width, glazed roof
£35,000 – £78,000
Wraparound side + rear
Full-width kitchen, dining and living in one L-shaped room
£60,000 – £128,000
Kitchen fit-out
Guide range
Notes
Mid-range kitchen
Rigid units, quartz or composite worktop, integrated appliances
£15,000 – £30,000
Most of our projects
High-specification kitchen
Bespoke or premium units, stone worktops, premium appliances, island with seating
£30,000 – £75,000
Bohun Grove EN4 level
Kitchen renovation without an extension
New kitchen in the existing footprint, walls opened up where needed
£15,000 – £40,000
See home renovation
Where the money goes
What a design and build price is made of, and which lines are priced separately.
Cost element
What it covers
How it is priced
Survey, design and approvals
Measured survey, architectural drawings, planning or lawful development certificate, building-regulations drawings, structural calculations
Included in the design and build price; council application fees at cost
Structural steelwork
Steels, padstones and the engineer's design where the back or outrigger walls come out
Typically £4,000–£12,000 on a Victorian terrace — in every estimate from day one
Shell
Foundations, drainage, walls, roof, rooflights, doors and windows to weather-tight
The largest share — priced from the survey and the drawings, not per m²
First and second fix
Electrics, plumbing, underfloor heating where specified, plaster, decoration, flooring fitted
Included; the items you choose (tiles, flooring, sanitaryware) are supplied by you or through us
Kitchen fit-out
Units, worktops, appliances
£15,000–£30,000 mid-range, £30,000–£75,000 high specification — priced separately from the build
Party wall
Notices to each adjoining owner; surveyor only if a neighbour dissents
£300 per notice at cost; surveyor from £750 per neighbour
Location
Access, parking, conservation conditions, logistics
Inner London +10–15%, Central London +20–25%, Hertfordshire about 5% less
Added afterwards
—
Nothing: the figure on your itemised estimate is the figure you pay
What the price includes: survey, architectural drawings, planning or lawful development certificate, building-regulations drawings, structural calculations, construction to plaster finish with first-fix electrics and plumbing, LABC sign-off and guarantees. On top: kitchen units, worktops and appliances (typically £15,000–£75,000), flooring and second-fix items you choose. The figure on your itemised estimate is the figure you pay — nothing is added afterwards. Postcode dependent — the instant estimator adjusts the range for your area in thirty seconds, and a detailed itemised estimate follows one survey.
What moves the price: the extension shape (a wraparound costs most because of the corner steel and the glazing); rooflights and the doors to the garden; how much of the back and outrigger walls come out — on a Victorian terrace budget £4,000–£12,000 of steel; moving the drainage, gas and water to a new kitchen position; and the kitchen specification, which can vary by £60,000 on the same room. Inner London (Camden, Islington, Hackney, Wandsworth, Hammersmith and similar) add 10–15%. Central London (Westminster, Kensington & Chelsea, the City) add 20–25%. Hertfordshire is about 5% less. These are estimated ranges — every home is surveyed and costed individually.
What the price includes
Design and build inclusive — one contract from the first sketch to the completion certificate.
Measured survey of the house and garden
Architectural design and drawings, with revisions until you're happy
Planning application or Lawful Development Certificate, prepared and submitted for you
Building regulations drawings and structural calculations by our chartered engineer
Party wall notices served on your behalf (£300 each, at cost)
Foundations, drainage and any build-over agreement with Thames Water
Structure, roof, rooflights, doors and windows to a weather-tight shell
Plaster finish, first-fix electrics and plumbing, underfloor heating where specified
Fitting of the kitchen, flooring and second-fix items you supply
LABC inspections and completion certificate
A dedicated project manager and a weekly progress update
12-month workmanship guarantee and structural guarantee; 10-year LABC Warranty available
Recent kitchen extension projects
Bohun Grove, East Barnet EN4 — rear extension, hip-to-gable loft and whole-house renovation
LABC 2024 Best Residential Extension in London
Semi-detached family home One programme loft + extension + renovation
A total renovation of a family semi: a rear extension opening into a full-width kitchen and dining space with floor-to-ceiling glazing and skylights, a hip-to-gable loft conversion with a rear dormer, two Lusso Stone bathrooms, enlarged bedrooms, new windows throughout, a regulated outbuilding and landscaping.
Because the loft and extension ran under one contract, the steelwork for the open-plan ground floor and the loft floor was designed together and lifted in on the same day — one crane hire, one scaffold, one building-control file.
See the Bohun Grove project · All projects
ANDERSON · FOUNDER, LCCL CONSTRUCTION
Anderson's advice: put the rooflights over the island
Rooflights over kitchen islands transform natural light more than any other single design decision. We position them on the plan before the kitchen layout is fixed, not after — moving a rooflight on a drawing costs nothing; moving one in a finished roof costs a week.
The second thing we say on every call: decide where the dining table goes first. Everything else — doors, lighting, the run of the units — follows from that.
“Extension built by LCCL Construction. We have just recently completed our ground floor house extension on our semi-detached home in Finchley. The services we used were for the design and build of the extension which is three meters and the full breadth of…”
EVA HALL · Trustpilot
“We are very happy with the services from Lccl, Alex has done a great job on design and construction. We have used Lccl in the past for our rear house extension and have come back to instruct Lccl for our loft conversion too to our house in North London. As…”
Mia M · Google Reviews
“Everyone at LCCL Construction was skilled, trustworthy and worked to the highest standard. I am delighted with our loft conversion, it is exactly what we wanted and I highly recommend the company - they have transformed the quality of my home. Overall it…”
KashImaging · Google Reviews
Cost questions we get asked most
Because it is the one line that varies by £60,000 on the same room — £15,000 for a good rigid-unit kitchen with a composite worktop, £75,000 for bespoke units, stone and premium appliances. We build the room to plaster and first fix, and fit the kitchen you choose, so you control that number.
Around £50,000–£65,000 for the build in 2026, plus the kitchen. A 4–5 m full-width rear extension of 18–25 m² is our most common kitchen-diner; add £15,000–£30,000 for a mid-range kitchen and you are planning around £65,000–£95,000 all in.
The kitchen units, worktops and appliances (priced in the second table), flooring and second-fix items you choose, bespoke joinery, council fees, and party wall surveyor fees if a neighbour dissents (from £750). Survey, design, approvals, structure, build, first fix, plaster, LABC sign-off and guarantees are in the build price.
Often, and it saves money: moving the drainage, gas and water to a new position is one of the hidden costs. We plan the kitchen layout with the extension drawings, not after, so the services go in once.
Yes. Inner London (Camden, Islington, Hackney, Wandsworth, Hammersmith and similar) adds 10–15%, Central London (Westminster, Kensington & Chelsea, the City) adds 20–25% and Hertfordshire is about 5% less — the difference is parking, access, conservation-area conditions, party wall complexity and logistics. The instant estimator applies the right band to your postcode.
No. The figure on your itemised estimate is the figure you pay — nothing is added afterwards. Items you choose, such as kitchen units or sanitaryware above the allowance, are listed separately before you sign.
Two steps. The instant estimator gives you a range for your postcode and project in thirty seconds. Then one measured survey gives you a detailed itemised estimate — design, planning, structure, construction and warranty priced line by line — with no obligation.
A 12-month workmanship guarantee and a structural guarantee on every project, with a 10-year LABC Warranty available. Building control sign-off is through LABC — we are an LABC Registered Partner and LABC Building Excellence Award winners in 2024 and 2026.
Where we build
From Finchley N3 we cover North London, North-West London, Central London, South-West and West London, and Hertfordshire — and we also work across the rest of London, Buckinghamshire, Surrey, Kent and Essex. Recent extensions: East Barnet EN4, Finchley N3, Putney SW15, Mill Hill NW7, Wood Green N22 and Borehamwood WD6.