Highgate, London
Areas · Camden · North London
Highgate · NW1 · NW3 · NW5

House extensions in Highgate

Highgate sits in Camden, where the streets are dominated by 1930s suburban semis where a rear-and-side wraparound is the obvious move. The build that pays back most reliably here is an L-shaped wraparound that finally squares off an awkward kitchen.

Typical all-in (inc VAT)
£136k–£201k
Build rate per m²
£3150–£4800
On-site programme
12–20 weeks

What we build in Highgate

Most Highgate 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, Georgian townhouses, Hampstead villas and 1960s ex-LA stock.

Side-returnRear extensionLoft (L-shaped dormer)

Extension costs in Highgate

A mid-spec 25 m² extension in Highgate typically lands between £136,000 and £201,000 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 £3150–£4800 per m² depending on glazing, structural spans and kitchen spend.

ProjectSizeHighgate all-in
Side return infill15–20 m²£102k – £151k
Full-width rear20–30 m²£136k – £201k
Wraparound30–45 m²£197k – £291k
Double-storey rear40–60 m²£265k – £392k

Planning permission in Highgate

Camden's conservation-area coverage is heavy in Hampstead, Primrose Hill and Fitzrovia. Rear extensions to 3m PD are often possible outside these zones but the planners scrutinise glazing and roof form closely.

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 Camden 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 mean two Party Wall Awards on almost every project.

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

Access is typically through the house, so expect dust protection, a boarded route and a skip permit from the council.

Every quote we issue for Highgate 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 Highgate

Adding floor area is usually cheaper than moving once stamp duty, agent fees and moving costs are counted.

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 Highgate use us

  • KYB-verified builders only
  • Live Camden project experience
  • Itemised fixed-price specifications
  • Insurance, warranty and accreditation checks
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