Kennington, London
Areas · Lambeth · South London
Kennington · SW2 · SW4 · SW8

House extensions in Kennington

Kennington sits in Lambeth, where the streets are dominated by post-war and inter-war housing with straightforward foundations and fewer planning constraints. The build that pays back most reliably here is a modest 3.5m rear extension under permitted development with rooflights over the island.

Typical all-in (inc VAT)
£113k–£173k
Build rate per m²
£2925–£4450
On-site programme
12–20 weeks

What we build in Kennington

Most Kennington 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 (Herne Hill, Clapham), Georgian townhouses (Kennington), 1930s stock in Streatham.

Side-returnRear extensionLoft

Extension costs in Kennington

A mid-spec 25 m² extension in Kennington typically lands between £113,000 and £173,000 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 £2925–£4450 per m² depending on glazing, structural spans and kitchen spend.

ProjectSizeKennington all-in
Side return infill15–20 m²£85k – £130k
Full-width rear20–30 m²£113k – £173k
Wraparound30–45 m²£164k – £251k
Double-storey rear40–60 m²£220k – £337k

Planning permission in Kennington

Well-established supplementary guidance on rear extensions. Conservation areas in Herne Hill, Clapham Old Town and Kennington need careful design of glazing and roof.

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 Lambeth 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 trigger two party walls; Kennington's Georgian stock adds vaults/basement complexity.

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

Narrow roads limit lorry size, so materials arrive in smaller loads; a good programme allows for it.

Every quote we issue for Kennington 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 Kennington

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 Kennington use us

  • KYB-verified builders only
  • Live Lambeth project experience
  • Itemised fixed-price specifications
  • Insurance, warranty and accreditation checks
Call now WhatsApp