House Extensions in Greenwich
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At Bigness Group, we design and build bespoke house extensions in Greenwich, combining precision engineering with contemporary design to create bright, functional spaces that enhance every home.
From heritage townhouses in Greenwich and Blackheath to modern family homes in Eltham and Charlton, we deliver tailored extensions that balance style, practicality, and long-term value.
Our team manages everything — planning, design, structural engineering, and construction — to ensure a seamless process and a flawless finish.
Design and Build Services
Our Greenwich design-and-build team delivers complete project management under one contract:
- Full measured survey and architectural design
- Planning applications and permitted development guidance through Greenwich Council
- Structural engineering and Building Control coordination
- Kitchen, dining, and interior layout optimisation
- Transparent scheduling and dedicated project management
From first sketch to completion, we ensure precision, accountability, and quality at every stage.
Types of Extensions We Build
We construct every major form of home extension across Greenwich, including:
• Glass Box Extensions – Contemporary builds with minimalist architecture.
• Modern House Extensions – Minimalist, light-filled architectural statements.
• Single-Storey Extensions – Bright, open spaces ideal for kitchens and dining.
• Double-Storey Extensions – Add new bedrooms or offices with a connected layout.
• Side-Return Extensions – Perfect for Victorian and Edwardian terraces in Blackheath.
• Rear Extensions – Create seamless links between home and garden.
• Wrap-Around Extensions – Combine rear and side infill for maximum living space.
• Conservatories & Orangeries – Elegant glazed spaces for year-round comfort.
• Loft & Garage Conversions with Extensions – Add vertical or lateral space for family growth.
Construction Standards
Every Greenwich project follows our proven high-quality build process:
- Groundworks & Foundations – Engineered for the borough’s varied terrain and sub-soils.
- Structural Framework – RSJs and steelwork for open-plan strength.
- Walls & Roofs – Matching brickwork or render with warm-roof insulation.
- Windows & Glazing – Energy-efficient materials compliant with current Part L standards.
- Interiors – Electrical, plumbing, flooring, and bespoke joinery to your specification.
- Sign-Off & Warranty – Building Control certification and workmanship guarantee.
Local Knowledge
We’re fully familiar with Greenwich Council’s planning and conservation regulations, covering protected zones like Greenwich Park, Blackheath, and Charlton Village.
Our experience navigating these local frameworks ensures smooth approvals and designs that respect the area’s architectural heritage.
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
Local expertise: deep knowledge of Greenwich’s planning and heritage policies.
Comprehensive service: design, approvals, and construction under one roof.
Certified professionals: compliant with all UK Building Regulations.
Transparent pricing: itemised quotations and milestone payments.
Trusted results: proven success across South East London.
Bigness Group delivers extensions that enhance lifestyle, add value, and stand the test of time.
FAQ
Do I need planning permission for an extension in Greenwich?
Many smaller builds fall under permitted development, but listed or conservation properties require planning consent. We handle every submission and drawing.
How long does the process take?
Typically 8–14 weeks for single-storey and 12–20 weeks for larger or two-storey extensions.
Can you work with listed buildings?
Yes — our architects are experienced with heritage conservation and material matching.
Do you provide full interior fit-outs?
Absolutely. We offer complete kitchen, flooring, and lighting installations.
Our Recent Projects in Greenwich
Recent projects include a modern kitchen extension in Blackheath, a double-storey family build in Eltham, and a glazed rear addition overlooking Greenwich Park. Each showcases our signature craftsmanship, energy efficiency, and clean architectural detailing. Bigness Group continues to be the trusted choice for homeowners seeking timeless extensions in South East London.
House Extensions in London by Borough
Bigness Group provides bespoke house extension services across all London boroughs, including Greenwich and the South East region. Our local planners and builders ensure every design meets council policies, complements its surroundings, and delivers lasting quality.
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.
