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Kitchen Extension Cost · Cobham

How much does a kitchen extension cost in Cobham?

A kitchen extension is one fixed build with a kitchen sitting on top of it, with estate access rules and working hours shaping the programme more than the fabric does. Calibrated to Cobham, a typical 30 m² kitchen-diner rear runs from around £136,000 with a self-managed kitchen to £188,000 and beyond for a bespoke one — the build barely moves, and the kitchen you choose is the whole difference.

Cost your Cobham kitchen extension See a sample report

One build, four budgets — calibrated to Cobham

The build is fixed; the kitchen is the variable. For a representative 30 m² kitchen-diner rear in Cobham, the project total climbs with the tier while the base underneath never moves.

Self-managed IKEA, self-fit
£8,000 – £10,000 £136,000 – £138,000
Supplied & fitted Howdens · Magnet · Benchmarx
£14,000 – £22,000 £142,000 – £150,000
Premium Local bespoke · Second Nature / Burbidge
£23,000 – £50,000 £151,000 – £178,000
Luxe & bespoke deVOL · Tom Howley · Plain English
£60,000+ £188,000+
The fixed build base — £4,255/m² · ~£128,000 on a 30 m² rear. Foundations and slab, walls and superstructure, roof, envelope and glazing, first-fix services, non-kitchen finishes, fees and contingency — and the structural knock-through, the steel and the opening between the existing house and the new room. Identical on every tier.

Figures at the BuildLens South East baseline, priced on current trade day rates and live merchant pricing (2026). Fully loaded — fees, contingency and VAT included. Totals scale with size, and firm to your own property with a report. The full tier ladder, with what each rung buys, sits on the main kitchen extension page.

The knock-through in Cobham

The Cobham kitchen extension is shaped by setting more than fabric — the modern stock takes knock-throughs predictably, while estate rules on working hours and access stretch the programme, and the specification the market expects sits at the top of the range.

The mechanics are the same everywhere: a wall comes out, an engineer-sized steel beam goes in to carry what it held, building control signs it off, and where the wall sits on or near a boundary, a party wall matter follows. All of it is standard, all of it is predictable from the property, and all of it is carried in the fixed build base — the tier ladder above sits on top of it, never inside it.

The full ladder, rung by rung. What each kitchen tier actually buys — and why bespoke is not the top rung — sits on the main kitchen extension page. This page is the Cobham calibration of it.

Kitchen extension cost — the full ladder →

Common questions about kitchen extension cost in Cobham

How much does a kitchen extension cost in Cobham?
On a representative 30 m² kitchen-diner rear calibrated to Cobham, the fully-loaded total runs from around £136,000 – £138,000 with a self-managed kitchen, through £142,000 – £150,000 supplied and fitted, to £151,000 – £178,000 for a premium or local-bespoke kitchen, and £188,000+ for a named bespoke maker. The build base is fixed at about £128,000; the kitchen tier sets where the total lands.
What is local about a Cobham kitchen extension?
The setting. The modern fabric takes the structural work predictably — fewer period surprises than almost anywhere in the Phase 1 list — but estate rules on hours, access and deliveries stretch the programme, and preliminaries run for as long as the job does. The specification expectation then does the rest.
Why does the kitchen choice change the total by so much?
Because the build behind it doesn't change. The structure, roof, envelope, services and the knock-through steel cost much the same whichever kitchen goes in — so the entire spread on the same extension sits in the kitchen tier. Picturing a bespoke kitchen on a mainstream budget is where most kitchen-extension budgets come apart.

Related Cobham pages

Extension cost in Cobham
The build side in full — shell versus all-in, calibrated locally.
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New kitchen cost in Cobham
The fit-out ladder without the build — and what is actually local about it.
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Kitchen extension cost — national
The full combined ladder and the method behind the Cobham figures.
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Guildford Beaconsfield Winchester Sevenoaks

Where does your Cobham kitchen extension fit in?

The right BuildLens report depends on why you are asking.

You're ready to build
Cost the whole job, itemised by trade and calibrated to your Cobham property.
Build Cost Intelligence · from £199
You're weighing extend against move
See the maths on staying and building versus selling and buying in Cobham, before you spend on drawings.
Extend or Move · £49
You're selling, and wondering if it pays
What the work costs set against what it returns in the Cobham market, before you commit.
Homeowners Market Intelligence · from £129
You're buying a Cobham property to extend
Cost the work properly before you commit to the purchase price.
Build Cost Intelligence · from £199