West Kensington, London
Areas · Hammersmith & Fulham · West London
West Kensington · W6 · W12 · W14

House extensions in West Kensington

West Kensington sits in Hammersmith & Fulham, where the streets are dominated by Edwardian bay-fronted semis with generous rear gardens and side access. The build that pays back most reliably here is a glazed side-return infill that pulls south light into a dark middle room.

Typical all-in (inc VAT)
£128k–£193k
Build rate per m²
£3025–£4625
On-site programme
12–20 weeks

What we build in West Kensington

Most West Kensington projects we scope fall into three buckets: a side-return or rear infill that fixes a dark galley kitchen, a full-width rear extension that opens the ground floor to the garden, and a rear-plus-loft package that adds a bedroom while the scaffold is already up. Victorian terraces (Fulham, Brook Green), Edwardian mansion blocks, Georgian in Hammersmith.

Side-returnRear extensionBasement dig

Extension costs in West Kensington

A mid-spec 25 m² extension in West Kensington typically lands between £128,000 and £193,000 all-in — that figure includes professional fees, planning and Building Control, party wall, a 12% contingency and VAT at 20%. Ex-VAT build rates run £3025–£4625 per m² depending on glazing, structural spans and kitchen spend.

ProjectSizeWest Kensington all-in
Side return infill15–20 m²£96k – £145k
Full-width rear20–30 m²£128k – £193k
Wraparound30–45 m²£186k – £280k
Double-storey rear40–60 m²£250k – £376k

Planning permission in West Kensington

H&F has a tightened basement policy since 2018 — feasibility on any dig-out needs early consultation. Conservation areas (Brackenbury, Hurlingham) are extensive.

Before you assume permitted development applies to your street, check whether your street falls inside a conservation area or an Article 4 direction — both are common in Hammersmith & Fulham and both remove PD rights for rear and side extensions. Our London planning guide walks through the tests in order.

Party wall and neighbours

Terraces + basement work = complex, often three-party party wall proceedings.

Serve notice at least two months before you break ground. Budget £1,200–£2,400 per adjoining owner if they dissent and appoint their own surveyor — see the Party Wall Act guide.

Access, logistics and site set-up

Tight on-street parking means bay suspensions and timed deliveries — your builder should price this, not absorb it.

Every quote we issue for West Kensington prices skip permits, parking suspensions, protection and welfare explicitly in the preliminaries — so the number you sign is the number you pay.

Value added in West Kensington

Light and layout move value here more than raw square metres — spend on glazing and ceiling height.

Typical programme

  1. Weeks 0–4Measured survey, design and structural calcs
  2. Weeks 4–12Planning or lawful development certificate, party wall notices
  3. Weeks 12–16Tender, builder selection and contract signing
  4. Weeks 16–34On site: groundworks, shell, watertight, first and second fix
  5. Week 35Building Control sign-off, snagging and handover

Full detail in the London extension timeline guide.

Why homeowners in West Kensington use us

  • KYB-verified builders only
  • Live Hammersmith & Fulham project experience
  • Itemised fixed-price specifications
  • Insurance, warranty and accreditation checks
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