Building cost in Wandsworth: 2026 rates.
Wandsworth is one of London's most active homeowner build markets. Rear extensions run £2,900–£4,000/m²; loft conversions £70k–£135k; full refurbs £2,400–£3,600/m² on 2026 rates. The borough's permitted development regime is more generous than Westminster or K&C, so kitchen extensions and lofts often go without full planning, keeping the design fee envelope lower.
| Project type | Typical 2026 cost |
|---|---|
| Rear extension | £2,900–£4,000/m² |
| Loft conversion (total) | £70,000–£135,000 |
| Full refurbishment | £2,400–£3,600/m² |
| Basement (per m²) | £4,800–£7,600/m² |
All figures exclude VAT (20% on most refurb/extension work), professional fees (8–14% typical), party wall awards and statutory costs.
- Wandsworth grants PD prior approval for 6m single-storey terrace extensions in most areas
- Conservation areas in Wandsworth Common, Tonsleys and Northcote remove PD rights
- Loft conversions on the borough's bay-fronted Victorian stock are highly standardised, pricing tighter than inner London
- Wandsworth Council has a published Code of Construction Practice with skip and noise restrictions
- Party Wall awards typically £900–£2,400 per adjoining owner
Wandsworth's PD regime simplifies the planning route; focus the cost expert work on quote review and monthly monitoring.
Frequently asked, Wandsworth
How much does a rear extension cost in Wandsworth?
A typical 4–6m single-storey rear extension on a Wandsworth Victorian terrace costs £75,000–£130,000 on 2026 rates, plus VAT, design and statutory costs. Sliding glazing, in-frame kitchens and stone floors push price toward the top of the band.
Can I extend under permitted development in Wandsworth?
Yes, Wandsworth follows the national PD regime, so a single-storey rear extension up to 6m on a terrace (8m detached) can be built under the larger home extension prior approval process, provided you are not in a conservation area or Article 4 zone.
How much does a Wandsworth loft conversion cost?
A standard L-shape loft on a Wandsworth Victorian terrace costs £85,000–£135,000 on 2026 rates including ensuite, plus VAT, design and party wall costs. Hip-to-gable conversions sit at the higher end; basic rear-dormer lofts start nearer £70k.
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