A house extension can transform your home, adding valuable living space. Costs cover foundations, structural work, roofing, glazing, internal fit-out, and connection to existing services. In St John's Wood (NW8), costs reflect the area's Inner Premium London market position, with a 15% premium over London averages.
St John's Wood is one of London's most exclusive residential areas, known for its large detached and semi-detached villas, leafy avenues, and proximity to Regent's Park. Many properties have substantial grounds.
| Specification | Price per sqm | Typical 25sqm Project | Includes |
|---|---|---|---|
|
Standard
Quality materials, clean design
|
£2,875 – £3,680 | £71,875 – £92,000 | All structural work, standard fixtures, full fit-out and decoration |
|
Premium
Designer brands, bespoke elements
|
£3,680 – £4,600 | £92,000 – £115,000 | Premium materials, designer fixtures, underfloor heating, smart controls |
|
Luxury
Finest materials, fully bespoke
|
£4,600 – £6,325 | £115,000 – £158,125 | Bespoke joinery, natural stone, top-tier appliances, architectural detailing |
Prices include VAT and are based on St John's Wood (NW8) market rates. Inner Premium London pricing reflects the high-quality specification expectations and heritage considerations common in this area. Actual costs depend on site-specific factors. All prices are guide estimates for 2025.
Here's what a typical 25sqm house extension project would cost in St John's Wood at each specification level.
The St John's Wood Conservation Area protects the distinctive low-density villa character. Extensions and alterations must respect the established building lines and garden settings.
Key streets and roads in St John's Wood include Hamilton Terrace, Cavendish Avenue, Avenue Road, Marlborough Place, Loudoun Road. Properties in these locations often have specific architectural characteristics that influence renovation costs, including large villa plots with complex foundation requirements, mature garden settings with TPOs, high-value properties requiring specialist insurance.
Every house extension is unique. Let our RIBA chartered architects provide a detailed, no-obligation estimate tailored to your property and specification.
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