House extension cost
in Twickenham.
Twickenham — TW1 — west of Richmond on the river. Generous Edwardian and inter-war housing, with the river, the rugby stadium and Marble Hill Park defining the local character.
What makes extension work in Twickenham distinct.
Housing: Edwardian terraces and semis, 1920s/30s housing, and some Victorian villas closer to the river.
Planning: Twickenham Riverside, Twickenham Green and Strawberry Hill conservation areas cover specific pockets.
Applications go to LB Richmond upon Thames. We submit on your behalf and handle party wall awards, build-over agreements and conservation officer correspondence end-to-end.
The five extension types — TW1 numbers.
All figures inclusive of design, planning, build, contingency and VAT. The Twickenham multiplier (0.95×) reflects local labour, scaffolding logistics, conservation requirements and finish expectations.
The 2026 London Extension Cost Guide.
Borough-by-borough pricing, a full £200k cost breakdown, PD vs full planning explained, and the seven hidden costs to watch for in Twickenham and beyond.
Send me the guide.
What Twickenham homeowners ask us.
How much does a house extension cost in Twickenham in 2026?
Typical 2026 Twickenham ranges (inc. design, planning, build, contingency & VAT): side-return extensions £86k–£152k; single-storey rear £105k–£200k; wraparound £162k–£304k; double-storey rear £171k–£361k; basement £238k–£713k. The Twickenham multiplier (0.95×) reflects local labour rates, scaffold logistics and finish expectations.
Do I need planning permission for an extension in Twickenham?
Twickenham Riverside, Twickenham Green and Strawberry Hill conservation areas cover specific pockets. Outside conservation areas, single-storey rear extensions up to 3m (terrace/semi) or 4m (detached) usually qualify for permitted development. Side-returns, wraparounds, double-storey extensions and anything in a conservation area need full planning. Applications go to LB Richmond upon Thames.
What extension type works best for Twickenham houses?
Edwardian terraces and semis, 1920s/30s housing, and some Victorian villas closer to the river. On this housing stock, the most common 2VP extension is a single-storey rear or wraparound — adding 20–35 m² of open-plan kitchen-diner. Double-storey extensions become viable on properties with rear gardens deep enough to absorb the additional volume without overshadowing.
How long does an extension take in Twickenham?
Allow 8–12 weeks for design and planning (longer in conservation areas), then 16–22 weeks on site for a single-storey, 22–30 weeks for a wraparound or double-storey, and 28–40 weeks for a basement. LB Richmond upon Thames processes planning applications in approximately 8–13 weeks depending on backlog.
What hidden costs catch Twickenham homeowners out on extensions?
In TW1 the top items are: party wall awards (£1,000–£3,000 per neighbour — common on terraced streets), build-over agreements with Thames Water (£300–£1,500 where drains run beneath the proposed extension), conservation officer consultations, structural engineer fees, drainage and asbestos surveys, and VAT at 20% on top of the base build cost. All of these are itemised in our fixed-price quote.
Does 2VP work on Twickenham extensions?
Yes — Twickenham is within our core London catchment. Our studio is at 20 Dawes Road in Fulham, 10.0km from Twickenham. We've delivered extensions across the TW1 postcode and our subcontractor network covers Richmond upon Thames. Free site visit, fixed-price quote, 10-year HomePro guarantee on the finished work.
Extension pricing for Twickenham’s neighbours.
Twenty minutes on site in Twickenham.
On us.
Nick Elias RIBA and Vladimir will visit your Twickenham home, walk the site, check planning constraints, advise on PD vs full planning, and give you a realistic budget and programme — even if an extension isn’t the right move.
One number. Sixty seconds. No callback.
Price your Twickenham extension using the same 2026 rate card we quote real clients with.
Price my Twickenham extension →