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.
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.
| Project | Size | West Kensington all-in |
|---|---|---|
| Rooflight conversion | 15–20 m² | £70k – £106k |
| Rear dormer kit | 20–28 m² | £128k – £193k |
| L-shaped dormer kit | 28–36 m² | £173k – £261k |
| Hip-to-gable + dormer | 30–40 m² | £192k – £290k |
Planning permission in West Kensington
H&F has a tightened policy on large mansard and hip-to-gable schemes since 2018 — feasibility 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 + structural loft 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
- Weeks 0–4Measured survey, design and structural calcs
- Weeks 4–12Planning or lawful development certificate, party wall notices
- Weeks 12–16Tender, builder selection and contract signing
- Weeks 16–34On site: groundworks, shell, watertight, first and second fix
- 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