Extension Cost · Ealing

How much does an extension cost in Ealing?

Ealing sits toward the top of the national range, but its defining feature is room — Edwardian semis on wider plots than most of London, which means bigger extensions and totals that scale with size as much as rate. A single-storey rear here runs from a shell figure around £3,930 per m² to an all-in nearer £6,470.

Cost your Ealing extension See a sample report

The figure you find isn't the figure you pay

As everywhere, most cost guides quote a shell rate — the bare build. It is not what lands on your account. Calibrated to Ealing, a single-storey rear looks like this per square metre.

The headline
you find

£3,930

Shell only — structure, roof, envelope. Per m².

What you
actually pay

£6,470

All-in with a fitted kitchen, fees, contingency and VAT. Per m².

On a typical 30 m² rear in Ealing, that is roughly £190,000 to £215,000 all-in — against a shell headline nearer £120,000. The difference is the fit-out, the professional fees, the contingency and the VAT the shell figure never included. Where in that range you land depends heavily on the property.

Figures calibrated from BuildLens South East build data — around 10% above the regional baseline — priced on current day rates and live merchant pricing (2026). The all-in assumes an entry-level bespoke kitchen from local joinery; a higher kitchen tier moves it further.

Why Ealing sits above the national range

Ealing's costs carry the standard London labour premium, but the local story is what the stock allows — and it allows more than most boroughs.

Edwardian semis with room to build

The Queen of the Suburbs was built generously: wide-fronted Edwardian semis with real gardens and side access many inner boroughs lost a century ago. Extensions here run larger — full-width rears, wraps, side additions — so while the per-square-metre rate matches the London norm, the footprints lift absolute totals above it.

Brentham and the conservation pockets

Brentham Garden Suburb carries tight protection, and conservation areas cover pockets across the borough. Where they apply, external alterations face the usual controls on materials and joinery; where they do not, Ealing builds more freely than inner London.

Loft-and-rear combinations are the local pattern

Ealing's stock takes a loft conversion and a rear extension in the same programme better than most, and combining them shares preliminaries, scaffold and disruption. It also multiplies the budget — which is exactly when an itemised figure earns its keep.

Where the money goes, itemised. The full anatomy of an extension — substructure through fit-out — and how BuildLens builds the number from method and live pricing, sits on the main extension cost page. This page is the Ealing calibration of it.

Extension cost — the full breakdown →

Common questions about extension cost in Ealing

How much does a single-storey rear extension cost in Ealing?

Calibrated to Ealing, the shell runs around £3,930 per m² and the all-in — with a fitted kitchen, fees, contingency and VAT — nearer £6,470. A typical 30 m² rear therefore lands roughly £190,000 to £215,000 all-in. The figure depends heavily on the specific property, which is what a desktop analysis of your address sets out.

Why do Ealing quotes differ from the national averages online?

Because most published figures are shell rates without fit-out, fees, contingency or VAT — and because they know nothing about Ealing: footprints that run larger than the London norm, and the combined loft-and-rear programmes the stock invites. The quote is usually not high; the headline was incomplete for this property in this place.

Do Ealing's bigger extensions change the cost calculation?

They change the totals more than the rate. A full-width rear on a wide Edwardian semi can run half as large again as the terrace norm, so at the same per-square-metre figure the absolute cost sits well above the London average. Size is the first thing to fix before any rate means anything — which is why a measured, property-specific figure matters more in Ealing than most places.

What pushes a Ealing extension over budget?

The property and the fit-out, usually — a kitchen or bathroom specified above the budget it was set against, and the local conditions above surfacing mid-job instead of being priced upfront. Both are predictable once the specific property is assessed, which is exactly what a BuildLens report does before you commit.