House Extensions in Wandsworth
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At Bigness Group, we design and build elegant, practical house extensions in Wandsworth, helping homeowners enhance space, functionality, and property value with precision and care.
From Victorian terraces in Battersea and Clapham Junction to period homes in Putney and Earlsfield, our bespoke extensions blend timeless design with modern comfort.
We manage the full process — from planning and design to construction and interiors — ensuring your extension is beautifully crafted, compliant, and built to last.
Design and Build Services
Our Wandsworth design-and-build team delivers a complete, end-to-end service:
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Measured survey and tailored architectural design
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Planning and permitted development advice for Wandsworth Council
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Structural engineering and Building Control coordination
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Kitchen, dining, and interior design for functional layouts
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Dedicated project management and milestone tracking
With Bigness Group, one trusted team oversees every stage — from first concept to handover — for a seamless, stress-free experience.
Types of Extensions We Build
We construct all major types of extensions across Wandsworth, including:
• Glass Box Extensions – Contemporary designs with clean lines and glass features.
• Modern House Extensions – Clean, minimalist structures with premium glazing.
• Single-Storey Extensions – Perfect for narrow Victorian or Edwardian homes in Battersea or Clapham.
• Double-Storey Extensions – Add bedrooms, bathrooms, or family rooms on both floors.
• Side-Return Extensions – Ideal for terraced homes in Bow, Stepney, and Limehouse.
• Rear Extensions – Create bright, open-plan spaces facing your garden.
• Wrap-Around Extensions – Combine side and rear extensions for maximum width.
• Conservatories & Orangeries – Stylish glazed designs for year-round comfort.
• Loft & Garage Conversions with Extensions – Turn unused spaces into practical, comfortable rooms.
• Basement Extensions – Create gyms, cinemas, or private lounges below ground.
Construction Standards
Every Bigness project in Wandsworth follows our rigorous six-step framework:
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Groundworks & Foundations – Engineered for South West London’s soil conditions.
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Structural Steelwork – RSJs and beams fitted for strong, open layouts.
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Walls & Roofs – Brick match, render, or cladding with high-performance insulation.
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Windows & Glazing – Energy-efficient materials meeting all UK standards.
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Interior Finishes – Electrical, plumbing, flooring, and joinery delivered to specification.
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Building Control & Warranty – Full compliance and long-term guarantee.
Local Knowledge
We have extensive experience with Wandsworth Council’s planning and conservation policies, including projects in Battersea, Wandsworth Town, and Putney.
Our understanding of heritage areas, building control, and modern design ensures your extension fits seamlessly within local architecture and passes approvals efficiently.
Costs and Financing
Every extension is unique, but here’s a general guide:
| Type | Typical Cost Range (2025) |
|---|---|
| Single-Storey Extension | £45,000 – £85,000 |
| Double-Storey Extension | £75,000 – £130,000 |
| Wrap-Around Extension | £90,000 – £160,000 |
| Side-Return Extension | £40,000 – £75,000 |
💡 Factors include size, materials, access, and specification level.
We provide transparent quotes with detailed breakdowns and stage payments.
Financing options may be available through our partner lenders for eligible clients — ask our team for guidance on home improvement financing.
The Process
1. Consultation & Site Visit – We meet you on-site to discuss ideas, goals, and feasibility.
2. Design & Planning – We prepare drawings, handle permissions, and finalise the budget.
3. Construction Phase – Our project manager oversees all work, ensuring safety and communication at every step.
4. Completion & Aftercare – Once finished, we conduct final inspections and provide warranty documentation.
We also offer optional maintenance plans to keep your new space performing at its best.
Why Choose Bigness Group
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Local expertise: deep understanding of Wandsworth’s housing and planning framework.
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Full-service delivery: design, permissions, construction, and interiors under one roof.
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Accredited professionals: compliant with all UK Building Regulations.
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Transparent pricing: fixed-cost quotes and milestone payments.
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Trusted reputation: proven results across South West London.
With Bigness Group, your home extension is more than an addition — it’s a long-term investment built around your lifestyle.
FAQ
Do I need planning permission for an extension in Wandsworth?
Some extensions qualify under permitted development, but larger or conservation-area builds require planning approval. We handle all documentation for you.
How long does construction take?
Typically 8–14 weeks for single-storey and 12–20 weeks for larger or multi-storey extensions.
Can you work on heritage and listed properties?
Yes — our architects are experienced in sensitive, conservation-approved designs.
Do you provide kitchen and interior installations?
Absolutely. We manage every stage from design to final finish, including bespoke interiors.
Our Recent Projects in Wandsworth
Recent projects include a double-storey rear extension in Putney, a glass-box kitchen addition in Clapham Junction, and a wrap-around family build in Earlsfield.
Each showcases Bigness Group’s commitment to craftsmanship, detail, and customer satisfaction.
House Extensions in London by Borough
Bigness Group designs and builds premium house extensions across all London boroughs, including Wandsworth and the wider South West area. Our deep local expertise, quality craftsmanship, and attention to detail ensure your extension is approved quickly, built efficiently, and finished to perfection.
Barking and Dagenham / Barnet / Bexley / Brent / Bromley / Camden / Croydon / Ealing / Enfield / Greenwich / Hackney / Hammersmith and Fulham / Haringey / Harrow / Havering / Hillingdon / Hounslow / Islington / Kensington and Chelsea / Kingston upon Thames / Lambeth / Lewisham / Merton / Newham / Redbridge / Richmond upon Thames / Southwark / Sutton / Tower Hamlets / Waltham Forest / Wandsworth / Westminster
Practical thinking for better-managed buildings.
Guidance, technical insight and practical perspectives on compliance, maintenance, building performance and long-term improvement.
