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 Chelsea (SW3, SW10), costs reflect the area's Prime Central London market position, with a 25% premium over London averages.
Chelsea is one of London's most affluent and fashionable neighbourhoods. The area features beautiful Georgian and Victorian townhouses, world-class shopping on the King's Road, and a rich artistic heritage.
| Specification | Price per sqm | Typical 25sqm Project | Includes |
|---|---|---|---|
|
Standard
Quality materials, clean design
|
£3,125 – £4,000 | £78,125 – £100,000 | All structural work, standard fixtures, full fit-out and decoration |
|
Premium
Designer brands, bespoke elements
|
£4,000 – £5,000 | £100,000 – £125,000 | Premium materials, designer fixtures, underfloor heating, smart controls |
|
Luxury
Finest materials, fully bespoke
|
£5,000 – £6,875 | £125,000 – £171,875 | Bespoke joinery, natural stone, top-tier appliances, architectural detailing |
Prices include VAT and are based on Chelsea (SW3, SW10) market rates. Prime Central London pricing reflects the premium specification expectations and specialist requirements typical 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 Chelsea at each specification level.
Multiple conservation areas cover Chelsea, including the Royal Hospital, Cheyne Walk, and Chelsea Park. Planning is rigorously controlled by RBKC.
Key streets and roads in Chelsea include Cheyne Walk, The Vale, Carlyle Square, Markham Square, Tite Street. Properties in these locations often have specific architectural characteristics that influence renovation costs, including premium material and finish expectations, complex basement regulations (RBKC subterranean policy), narrow mews access, Thames flood risk for riverside properties.
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