SEMI-DETACHED HOUSE EXTENSION LONDON


H1: Semi-Detached House Extension London – Rear, Side & Wrap-Around Extensions | LASTING LTD
A semi-detached house extension is one of the best ways to expand ground-floor living space, increase natural light and add significant property value.
LASTING LTD builds high-quality extensions for semi-detached homes across London — including rear extensions, side extensions, double-storey and wrap-around configurations.
Structural RSJ included • Fast construction • Premium finishing • Free site visit
Why Semi-Detached Extensions Are Ideal for London Homes
Semi-detached homes offer major design flexibility:
Large open-plan kitchen/living layouts
Perfect for bifold or sliding door openings
Plenty of sunlight from side + rear
More structural options vs terraced houses
Excellent ROI (+15–25% property value)
Suitable for:
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Open-plan kitchen diners
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Family living areas
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Utility rooms / office space
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Larger rear lounges
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Additional bathrooms
Why Choose LASTING LTD
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10+ years experience with semi-detached extensions
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Structural steel RSJ beams included
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Architectural drawings & engineering support
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Building Control + planning assistance
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Full project management
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Clean, fast, reliable workmanship
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Premium finishing & attention to detail
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Transparent fixed pricing
CTA: Get a Free Semi-Detached Extension Quote
Types of Semi-Detached Extensions We Build
1. Rear Extension (Most Popular)

Ideal for:
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Large kitchen diner
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Open-plan living room
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Modern glazing & skylights
Benefits:
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Fastest approval
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Strongest resale value
2. Side Extension / Side Return Extension


Perfect for:
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Widening a narrow kitchen
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Extending utility rooms
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Creating additional floor area
Side spaces in semi-detached houses are often underused → ideal for extension.
3. Wrap-Around Extension


The premium option combining rear + side, giving massive open-plan space.
Best for:
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Luxury kitchen diner
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Large folding/sliding doors
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Complete ground-floor reconfiguration
4. Double-Storey Semi-Detached Extension


Adds:
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New bedroom(s)
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En-suite
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Extended ground floor
Most cost-effective per m² of new space.
What’s Included in the Build
Structural
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RSJ steel beams
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Load-bearing wall removal
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New foundations
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Drainage works
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Brick/blockwork
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Roof (flat/pitched)
External
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Bifold/sliding doors
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Skylights / roof lanterns
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Insulation to Building Regs
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Rendering, brick slips or cladding
Internal
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Plumbing & heating
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Electrical installation
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Underfloor heating (optional)
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Plastering & painting
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Flooring: tiles, wood, LVT
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Kitchen fitting (optional)
Management
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Dedicated project manager
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Weekly progress updates
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Building Control compliance
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Snagging + final certification
Semi-Detached House Extension Cost (London 2025)
| Type | Typical Cost |
|---|---|
| Rear extension (single storey) | £35,000–£60,000 |
| Side extension | £25,000–£45,000 |
| Wrap-around extension | £65,000–£140,000 |
| Double-storey extension | £60,000–£120,000 |
All prices include: Labour
Materials
Structural steel
Project management
Finishing
CTA: Request a Personalised Quote
Timeline
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Design & planning: 2–6 weeks
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Structural & groundworks: 3–6 weeks
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Roofing & glazing: 1–2 weeks
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Interiors & finishing: 3–6 weeks
Average total: 10–14 weeks
Benefits of Working With LASTING LTD
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Guaranteed premium finish
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Fast start dates in North & East London
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Experienced structural team
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Excellent communication
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Absolutely no hidden costs
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We handle everything from drawings to completion
Areas We Cover
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Enfield
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Barnet
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Haringey
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Edmonton
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Palmers Green
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Walthamstow
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Muswell Hill
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Finchley
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Tottenham
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North London
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East London
Related Services:
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House Extension London
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Single Storey Extension
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Timber Frame Extension
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Loft Conversion London
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Structural RSJ Installation
Related Areas:
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Builder in North London
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Builder in Enfield
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Builder in Barnet
Start Your Semi-Detached House Extension Today
Transform your ground floor into a bright, modern open-plan space.
Fast, reliable and fully managed by LASTING LTD.
CTA:
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Get a Free Quote
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WhatsApp Us (Fast Response)
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Book a Site Visit
