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Unit 3, Palace Court, 250 Finchley Road, London NW3 6DN
🏡 SEMI-DETACHED EXTENSION SPECIALISTS 🏡

Semi-Detached House Extensions Across Hampstead, Camden & North London

Unlock your semi's potential with expertly designed single storey, double storey and wraparound extensions that add valuable living space, create open-plan kitchens and transform family homes for modern living.

400+ Semi Extensions
Party Wall Experts
Planning Approved

Semi-Detached Extension Specialists Across North London

With over 400 semi-detached extensions completed, we understand how to maximise your home's potential while managing Party Wall requirements and planning constraints.

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Single Storey Experts

Rear and side extensions creating open-plan kitchen-diners with bi-fold doors, roof lanterns and seamless garden connections that transform how you live.

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Double Storey Specialists

Two-storey rear extensions adding master suites, additional bedrooms and bathrooms above expanded ground floor living spaces for growing families.

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Party Wall Management

Complete Party Wall service including surveyor appointments, neighbour communication and award documentation. We've successfully managed thousands of Party Wall agreements.

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Material Matching

Expert sourcing of matching bricks, roof tiles and render to ensure your extension integrates seamlessly with your existing 1930s semi, Victorian or Edwardian home.

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Light-Filled Design

Roof lanterns, Velux windows, Crittall-style glazing and bi-fold doors engineered to flood your new space with natural daylight throughout the year.

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10-Year Structural Warranty

All extensions include building control sign-off, structural engineer certificates and a comprehensive 10-year insurance-backed warranty.

Recent Semi-Detached Transformations

A selection of single storey, double storey and wraparound extensions delivered for semi-detached homeowners across North London.

Double Storey Rear Extension
Muswell Hill, N10
1930s Semi Wraparound
Golders Green, NW11
Side & Rear Extension
Finchley, N3
Open-Plan Kitchen Extension
East Finchley, N2
Victorian Semi Extension
Crouch End, N8
Modern Flat Roof Extension
Hendon, NW4

The Semi Extension Journey

A proven approach delivering beautiful extensions with careful neighbour management and minimal disruption.

1

Site Survey & Feasibility

We assess your property, review Permitted Development options, discuss design possibilities and provide guidance on Party Wall requirements and planning strategy.

2

Design & Approvals

Architectural drawings, structural calculations and planning applications where required. Party Wall notices served and agreements progressed in parallel.

3

Construction Phase

Foundations, steelwork and building works with daily site management, neighbour communication and thorough protection of your existing home.

4

Fit-Out & Completion

Kitchen or bathroom installation, electrics, plumbing, flooring and decoration followed by building control sign-off and warranty handover.

Trusted by Semi Homeowners

Read what homeowners say about their semi-detached extension experience.

★★★★★

"Our 1930s semi now has a stunning double storey extension with master suite above and open-plan kitchen below. The team matched our original bricks perfectly."

David & Emma Collins
Muswell Hill, N10
★★★★★

"They handled Party Wall negotiations brilliantly – our neighbour was initially concerned but the team's professionalism won them over. The extension is everything we wanted."

Sarah Thompson
Golders Green, NW11
★★★★★

"A wraparound extension transformed our cramped semi into a spacious family home. The roof lantern brings amazing light into our new kitchen-diner."

Michael & Lisa Chen
Finchley, N3

Semi-Detached Extension Specialists Across North London

Serving suburban neighbourhoods from Hampstead to Barnet, Finchley to Muswell Hill.

NW11

Golders Green & Hampstead Garden Suburb

Golders Green, Temple Fortune, Hampstead Way, North End, Childs Hill.

N3

Finchley Central

Finchley Central, Church End, Hendon Lane, Regents Park Road, Dollis Park.

N2

East Finchley

East Finchley, Fortis Green, Cherry Tree Wood, Bishops Avenue, Market Place.

N10

Muswell Hill

Muswell Hill, Alexandra Park, Fortis Green, Cranley Gardens, Queens Avenue.

NW4

Hendon

Hendon, Brent Cross, West Hendon, Colindale, Sunny Hill Park.

N8

Crouch End & Hornsey

Crouch End, Hornsey, Stroud Green, Harringay, Hornsey Vale.

N12

North Finchley

North Finchley, Woodside Park, Friern Barnet, Whetstone, Totteridge Lane.

N20

Whetstone & Totteridge

Whetstone, Totteridge, Oakleigh Park, Brunswick Park, Friern Barnet.

Semi-Detached Extension FAQs

Expert answers to common questions about extending semi-detached properties.

What extension options are available for semi-detached houses?
Semi-detached homes offer excellent extension potential including single storey rear extensions, side extensions into the garden, double storey rear extensions, wraparound L-shaped extensions, and over-garage extensions where applicable.
How much does a semi-detached extension cost?
Semi-detached extensions typically range from £50,000 to £150,000. Single storey rear extensions start around £45,000, while double storey extensions range from £80,000 to £150,000+ depending on size and specification.
Do I need planning permission for a semi extension?
Many single storey rear extensions up to 6 metres qualify under Permitted Development. Side extensions, double storey extensions and larger projects usually require planning permission. We handle all applications and provide pre-application advice.
How long does a semi-detached extension take?
Single storey extensions typically take 10-14 weeks on site. Double storey extensions require 14-20 weeks. We provide detailed programmes before works begin, including Party Wall timescales where applicable.
Will I need a Party Wall agreement?
Most semi-detached extensions require Party Wall agreements with your attached neighbour. We manage the entire process including serving notices, surveyor appointments and award documentation.
Can you match the existing house style?
Absolutely. We source matching bricks, roof tiles and materials to ensure seamless integration with your existing property, whether 1930s semi, Victorian villa or more contemporary home.

Request Your Free Site Survey

Share details about your semi-detached home and our team will arrange a survey to discuss your extension options.

Free Site Survey
Party Wall Guidance
10-Year Warranty
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