Westminster · London
Kitchen Extension in Westminster
Central borough with listed and conservation stock — interior and basement work dominates.
Westminster
Kitchen Extension specialists across Westminster.
We deliver kitchen extension projects across the full Westminster postcode set — W1, SW1, NW1, NW8. Central borough with listed and conservation stock — interior and basement work dominates.
A kitchen extension combines a structural extension — side return, rear or wraparound — with a complete kitchen design and installation as a single fixed-price project. It's the most common instruction we receive across London: a homeowner who wants an open-plan kitchen-diner with garden views but doesn't want to manage a builder and a kitchen supplier separately. We handle design, consent, structural build, kitchen supply and installation start to finish. One contract, one project manager, one fixed price.
Every Westminster project includes a free desk-based planning assessment before we quote. We know the local planning officers, party wall surveyors and approved inspectors by name.
Costs
Kitchen Extension cost in Westminster 2026.
| Configuration | Cost range | Timeline |
|---|---|---|
| Side return extension + kitchen (3m wide) | £65,000–£90,000 | 10–13 wks |
| Rear extension + kitchen (3–4m deep) | £75,000–£105,000 | 11–14 wks |
| Rear extension + kitchen (5–6m deep) | £90,000–£120,000 | 12–15 wks |
| Wraparound + premium kitchen | £110,000–£130,000 | 14–16 wks |
Local advantage
Eight years of kitchen extension work in Westminster.
Familiarity with Westminster's planning officers, party wall surveyors and approved inspectors cuts weeks off the approval timeline. We deliver consistent quality across all 4 postcodes the borough covers.
Recent Westminster work
Kitchen Extension examples.
Builderr vs other London builders.
The construction industry has a wide distribution of operators. Here's what changes between a directly-employed, fixed-scope outfit and the alternatives.
| Criterion | Builderr | Typical London builder | Cowboy outfit |
|---|---|---|---|
| Labour model | Directly employed team (PAYE) | Mixed subcontract gangs | Day-rate cash labour |
| Pricing | Fixed-scope itemised quote | Estimate + provisional sums | Verbal price + variations |
| Design & engineering | In-house architect + SE | Outsourced, separate billing | Builder draws on the back of an envelope |
| Planning + LDC handled | Yes — included in price | Often charged extra | Builder asks you to apply |
| Party wall surveyors | Instructed by us | Your responsibility | Skipped (illegal) |
| Building control | Plans + site inspections booked by us | Building Notice route | Not registered |
| Project management | Dedicated PM, weekly photo updates | Foreman doubles up | Owner-manager juggles 5 jobs |
| Payment schedule | Stage payments against signed-off milestones | Weekly invoices | Cash up front |
| Insurance | £10M PL + 10yr structural warranty | £2–5M PL only | No documented cover |
| Snags at handover | <3 typical | 20–30 typical | Walk-off mid-job common |
| Variation creep | 0% — fixed scope | +15–25% over original quote | +40%+ regularly |
Save £19,500–£43,875 on a kitchen extension in Westminster.
Industry data (FMB, RICS, Which? Trusted Trader 2024) shows the average London construction project overruns by 18–22% on cost and 25–35% on time. Fixed-scope contracts with a single accountable team eliminate that variance. The savings above assume a typical project at £97,500.
FAQ
Kitchen Extension in Westminster.
How much does a kitchen extension cost in Westminster?+
Kitchen Extension projects in Westminster typically cost £65,000–£130,000. Westminster sits across postcodes W1, SW1, NW1, NW8; local rates align with the wider London market.
Do kitchen extensions in Westminster need planning permission?+
Central borough with listed and conservation stock — interior and basement work dominates. We carry out a free desk-based planning assessment for your specific address before quoting, identifying whether permitted development, prior approval, or full planning applies.
Do you work across all Westminster postcodes?+
Yes — we deliver kitchen extension projects across all Westminster postcodes including W1, SW1, NW1, NW8.
How much does a kitchen extension cost in London 2026?+
A kitchen extension combining structural build and kitchen fit-out typically costs £65,000–£130,000 in London. A side return + standard kitchen runs £65–90k; a rear extension + premium kitchen + premium glazing sits at £100–130k+.
Do I need planning permission for a kitchen extension?+
Most single-storey kitchen extensions fall under permitted development (up to 3m deep) or the Larger Home Extension scheme (up to 6m). Conservation areas and Article 4 zones need full planning. We assess your specific address on every quote.
Get a Westminster kitchen extension quote.
Senior consultant call within one business hour. Fixed-scope quote for your Westminster project — no provisional sums.
Other types in Westminster
Explore other build types in Westminster.
Kitchen Extension across London