Building cost in Southwark: 2026 rates.
Southwark covers everything from Bermondsey warehouse conversions to East Dulwich terraces, so cost varies sharply with property type. Rear extensions run £2,800–£3,900/m²; loft conversions £65k–£130k; refurbs £2,300–£3,500/m² on 2026 rates. The borough's Article 4 directions across Dulwich, Camberwell and Borough remove permitted development on most protected streets.
| Project type | Typical 2026 cost |
|---|---|
| Rear extension | £2,800–£3,900/m² |
| Loft conversion (total) | £65,000–£130,000 |
| Full refurbishment | £2,300–£3,500/m² |
| Basement (per m²) | £4,700–£7,400/m² |
All figures exclude VAT (20% on most refurb/extension work), professional fees (8–14% typical), party wall awards and statutory costs.
- Dulwich Estate scheme of management (separate from planning) controls external changes on 1,500+ properties
- Article 4 directions across Dulwich Village, Camberwell Grove and Bankside remove PD rights
- Loft and side-return extensions are the dominant homeowner project types in SE15 and SE22
- Southwark's basement SPD restricts excavation under gardens
- Party Wall Act 1996 awards typically £900–£2,400 per adjoining owner on terrace work
Dulwich Estate scheme is an extra consent regime on top of planning, programme and fees need to allow for it.
Frequently asked, Southwark
How much does a Dulwich extension cost?
A rear extension on a Dulwich Victorian or Edwardian house costs £75,000–£140,000 on 2026 rates, plus VAT, fees and statutory costs. Dulwich Estate scheme of management approval is required on most properties and adds 6–12 weeks to programme.
Is permitted development available in Southwark?
Permitted development applies to many Southwark terraces, but Article 4 directions in Dulwich, Camberwell Grove, Bankside and the central conservation areas remove key PD rights. Always check the borough's Article 4 schedule and any Dulwich Estate scheme before assuming PD.
How much is a Southwark loft conversion?
A standard rear-dormer loft on a Southwark Victorian terrace costs £65,000–£100,000; an L-shape with ensuite £85,000–£130,000. Mansard conversions in Article 4 zones typically need planning and run at the top of the range.
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