Kitchen Extension Cost · Sevenoaks

How much does a kitchen extension cost in Sevenoaks?

A kitchen extension is one fixed build with a kitchen sitting on top of it, and Sevenoaks kitchens tend to be big, so totals climb through size as well as tier. Calibrated to Sevenoaks, 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 Sevenoaks kitchen extension See a sample report

One build, four budgets — calibrated to Sevenoaks

The build is fixed; the kitchen is the variable. For a representative 30 m² kitchen-diner rear in Sevenoaks, 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 Sevenoaks

Sevenoaks kitchen extensions run big — the detached stock takes full-width kitchen-diners well beyond the 30 m² norm, so totals here climb through size before the tier question is even asked, and the period houses and oasts among the stock carry structural work sized for their actual fabric.

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 Sevenoaks calibration of it.

Kitchen extension cost — the full ladder →

Common questions about kitchen extension cost in Sevenoaks

How much does a kitchen extension cost in Sevenoaks?

On a representative 30 m² kitchen-diner rear calibrated to Sevenoaks, 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.

Why do Sevenoaks kitchen extension totals run above the representative figure?

Size, mostly. The representative totals assume a 30 m² room; Sevenoaks detached stock routinely takes 40 m² and beyond, and at the same rate the total scales with the footprint. The tier ladder then moves it further. A report fixes both to your actual property rather than the representative case.

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.