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:
Open-plan kitchen diners
Family living areas
Utility rooms / office space
Larger rear lounges
Additional bathrooms
Why Choose LASTING LTD
10+ years experience with semi-detached extensions
Structural steel RSJ beams included
Architectural drawings & engineering support
Building Control + planning assistance
Full project management
Clean, fast, reliable workmanship
Premium finishing & attention to detail
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:
Large kitchen diner
Open-plan living room
Modern glazing & skylights
Benefits:
Fastest approval
Strongest resale value
2. Side Extension / Side Return Extension


Perfect for:
Widening a narrow kitchen
Extending utility rooms
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:
Luxury kitchen diner
Large folding/sliding doors
Complete ground-floor reconfiguration
4. Double-Storey Semi-Detached Extension


Adds:
New bedroom(s)
En-suite
Extended ground floor
Most cost-effective per m² of new space.
What’s Included in the Build
Structural
RSJ steel beams
Load-bearing wall removal
New foundations
Drainage works
Brick/blockwork
Roof (flat/pitched)
External
Bifold/sliding doors
Skylights / roof lanterns
Insulation to Building Regs
Rendering, brick slips or cladding
Internal
Plumbing & heating
Electrical installation
Underfloor heating (optional)
Plastering & painting
Flooring: tiles, wood, LVT
Kitchen fitting (optional)
Management
Dedicated project manager
Weekly progress updates
Building Control compliance
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
Design & planning: 2–6 weeks
Structural & groundworks: 3–6 weeks
Roofing & glazing: 1–2 weeks
Interiors & finishing: 3–6 weeks
Average total: 10–14 weeks
Benefits of Working With LASTING LTD
Guaranteed premium finish
Fast start dates in North & East London
Experienced structural team
Excellent communication
Absolutely no hidden costs
We handle everything from drawings to completion
Areas We Cover
Enfield
Barnet
Haringey
Edmonton
Palmers Green
Walthamstow
Muswell Hill
Finchley
Tottenham
North London
East London
Related Services:
House Extension London
Single Storey Extension
Timber Frame Extension
Loft Conversion London
Structural RSJ Installation
Related Areas:
Builder in North London
Builder in Enfield
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:
Get a Free Quote
WhatsApp Us (Fast Response)
Book a Site Visit
LASTING LTD
Premium property renovation & construction company in London.
WhatsApp:
07448 886776
info@lastingltd.com
Office Address
London
34 Pine House
9 Droop Street
W10 4EJ
