House extension cost
in Herne Hill.
Herne Hill — SE24 — between Brixton and Dulwich. Victorian villas and Edwardian terraces dominate, with one of inner-south London's strongest family-buyer markets.
What makes extension work in Herne Hill distinct.
Housing: Victorian villas, Edwardian terraces with outriggers, and some inter-war housing on the southern fringes.
Planning: Herne Hill Conservation Area covers most of the central streets. Article 4 applies in places.
Applications go to LB Lambeth & LB Southwark. We submit on your behalf and handle party wall awards, build-over agreements and conservation officer correspondence end-to-end.
The five extension types — SE24 numbers.
All figures inclusive of design, planning, build, contingency and VAT. The Herne Hill 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 Herne Hill and beyond.
Send me the guide.
What Herne Hill homeowners ask us.
How much does a house extension cost in Herne Hill in 2026?
Typical 2026 Herne Hill 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 Herne Hill multiplier (0.95×) reflects local labour rates, scaffold logistics and finish expectations.
Do I need planning permission for an extension in Herne Hill?
Herne Hill Conservation Area covers most of the central streets. Article 4 applies in places. 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 Lambeth & LB Southwark.
What extension type works best for Herne Hill houses?
Victorian villas, Edwardian terraces with outriggers, and some inter-war housing on the southern fringes. 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 Herne Hill?
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 Lambeth & LB Southwark processes planning applications in approximately 8–13 weeks depending on backlog.
What hidden costs catch Herne Hill homeowners out on extensions?
In SE24 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 Herne Hill extensions?
Yes — Herne Hill is within our core London catchment. Our studio is at 20 Dawes Road in Fulham, 8.0km from Herne Hill. We've delivered extensions across the SE24 postcode and our subcontractor network covers Lambeth / Southwark. Free site visit, fixed-price quote, 10-year HomePro guarantee on the finished work.
Extension pricing for Herne Hill’s neighbours.
Twenty minutes on site in Herne Hill.
On us.
Nick Elias RIBA and Vladimir will visit your Herne Hill 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 Herne Hill extension using the same 2026 rate card we quote real clients with.
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