LABC Awards
Winners 2024
200+ Reviews
4.7 / 5 Rating
20+ Years
Experience
NFB
Members
LABC
Partners
House Extension Builders London - Award-Winning Design & Build
Create the space you need with a beautifully designed house extension by LCCL Construction. Our house extension builders handle everything from architectural design to construction and finishing — one company, one estimate, one point of contact.
Have a Question?
020 8037 7332
LABC AWARD
WINNERS 2024
4.7/5
200+ Reviews
20+
Years Experience
NFB
Members
LABC
Registered
House Extensions Our Builders Design & Build in London
Rear Extension
The most popular type. Extends from the back of your property. 3 to 6 metres.
from £35,000
Side Return Extension
Infills the narrow side alley. Perfect for Victorian and Edwardian terraces.
from £35,000
Kitchen Extension
Open-plan kitchen-diners with bi-fold doors, skylights and roof lanterns.
from £40,000
Rear & Side Extension
Maximum ground floor space on semi-detached and detached properties.
from £55,000
Wraparound Extension
Combined rear and side return. L-shaped addition for maximum space.
from £60,000
Double-Storey Extension
Ground and first floor space. The most cost-effective way to add large areas.
from £80,000
Please note: Every project is bespoke and individually designed. All costs are indicative and subject to final drawings, specification, location and scope of works. A detailed written quote will be provided following your consultation.
Why Choose LCCL as Your House Extension Builders in London?
LABC Award Winners 2024 — Best Residential Extension London
20+ Years Experience in residential design and build
One Company Does Everything — no separate architects, engineers, builders
LABC Registered Partners — highest building standards
200+ Verified Reviews rated 4.7/5 across Google, Houzz & Trustpilot
NFB Members — National Federation of Builders
Detailed-Price Quotes with no hidden costs
10-Year LABC Warranty available on every project
How It Works
Our experienced extension builders manage every stage — from design to handover — across London and Hertfordshire.
1
Free Consultation
We discuss your project, assess your property and explain your options.
2
Design
Full architectural drawings, planning applications and building regulations
3
Build
Expert construction with a dedicated project manager from start to finish.
4
Completion
Building control sign-off, snagging and handover. Ready to enjoy.
Our Work
What Our Clients Say
Don't just take our word for it — here's what homeowners across London say about our house extension builders.
"In just over 6 months LCCL managed to transform my 1900s mid-terrace house. Super professional and on the ball at all times."
Matt EL
Houzz
"Reliable, fast, trustworthy and very organised. Our extension looks great and we would recommend."
Alex Gray
Google Reviews
"We used LCCL for our rear house extension and have come back for our loft conversion too. Great job."
Mia M
Google Reviews
Frequently Asked Questions
How much does a house extension cost in London?
House extension costs range from £35,000 to £150,000 depending on the type. Rear extensions from £35,000, side return from £35,000, kitchen extensions from £40,000, wraparound from £60,000. All prices include full design and build. Our house extension builders provide detailed written quotes with no hidden costs.
Do I need planning permission?
Most single-storey rear extensions fall under permitted development and do not need planning permission. Extensions exceeding size limits, in conservation areas or on listed buildings require planning. We handle all applications.
How long does a house extension take?
Typically 10 to 18 weeks to build depending on the type. The full timeline from consultation to completion is 4 to 8 months.
Can I stay in my house during the build?
Yes. Most extensions are built from the outside and the opening into your existing house is one of the last stages. You do not usually need to move out.
Areas We Cover
We design and build house extensions across London and Hertfordshire including Barnet, Finchley, Hendon, Muswell Hill, Highgate, Hampstead, Southgate, Enfield, Edgware, Crouch End, Hackney, Islington, Camden, Clapham, Putney, Wandsworth, Ealing, Borehamwood, St Albans, Potters Bar, Bushey, Watford and all surrounding areas. LCCL Construction are specialist house extension builders and home extension contractors trusted across London and Hertfordshire.
Book Your Free Consultation Today
London's trusted house extension builders — one company, one estimate, one point of contact from design to completion
020 8037 7332 | info@lcclconstruction.co.uk
LCCL Construction | 3rd Floor, Hathaway House, Popes Drive, Finchley, London N3 1QF | 020 8037 7332
House Extension Company London Limited. Trading as "LCCL Construction" Registration: 16618197
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