What we build in Balham
Most Balham 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 and Edwardian terraces at scale — Tooting, Balham and Battersea are the classic side-return heartland.
Extension costs in Balham
A mid-spec 25 m² extension in Balham typically lands between £119,000 and £179,000 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 £2975–£4550 per m² depending on glazing, structural spans and kitchen spend.
| Project | Size | Balham all-in |
|---|---|---|
| Side return infill | 15–20 m² | £89k – £134k |
| Full-width rear | 20–30 m² | £119k – £179k |
| Wraparound | 30–45 m² | £173k – £260k |
| Double-storey rear | 40–60 m² | £232k – £349k |
Planning permission in Balham
Wandsworth has published clear extension SPDs and is one of the more predictable planning boroughs. Conservation zones (Nightingale, Battersea Park) tighten design review.
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 Wandsworth and both remove PD rights for rear and side extensions. Our London planning guide walks through the tests in order.
Party wall and neighbours
Two party wall Awards on almost every terrace 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
Rear access via a side alley or garden gate speeds up muck-away and cuts labour cost noticeably.
Every quote we issue for Balham 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 Balham
Well-executed extensions here tend to return a healthy share of their cost at resale, particularly where they add a genuine third or fourth bedroom.
Typical programme
- Weeks 0–4Measured survey, design and structural calcs
- Weeks 4–12Planning or lawful development certificate, party wall notices
- Weeks 12–16Tender, builder selection and contract signing
- Weeks 16–34On site: groundworks, shell, watertight, first and second fix
- Week 35Building Control sign-off, snagging and handover
Full detail in the London extension timeline guide.
Why homeowners in Balham use us
- KYB-verified builders only
- Live Wandsworth project experience
- Itemised fixed-price specifications
- Insurance, warranty and accreditation checks