Find affordable London extension builders

Prices range from cheapest £30/hour and £177/day (Nisup Building Services) to £71/hour and £327/day (RTC Plumbers) - average £42/hr and £264/day

Need help with a job?

Or call 02046521400
HaMuch is Excellent

Local London extension builders & latest jobs

J&J Building Solutions

£41/hour

£256/day

(rates verified 18/09/26)

Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in London. No obligation free quot...

"Change mascerator as its overflowing, its behind a cabinet that would need to be o pened up" - SE18, job posted 21/09/26

RTC Plumbers

£71/hour

£177/day

(last active 22/09/26)

Welcome to RTC Plumbers! With over 15 years of experience, we offer a range of plumbing services from simple repairs to complex installations, each...

"Build a dormer loft conversion" - BR3, job posted 19/09/26

GR MAINTENANCE LTD

£37/hour

£236/day

Member since April 2025

Trusted and professional extension builder in London. Experienced in all extension buildering work and keeping within budget and on quote. GR MAINT...

"Two storey extension" - RM15, job posted 17/09/26

Nisup Building Services

£30/hour

£240/day

(last active 22/09/26)

NISUP BUILDING SERVICES Company specializes in the domestic and commercial building industry :1. Refurbishm...

"Convert a Garage" - SE13, job posted 14/09/26

Glenward Builders Ltd

£42/hour

£259/day

(last active 22/09/26)

Experienced extension builder ready to quote for your work. Glenward Builders Ltd is the best extension builder in London. No obligation free quote...

"Loft conversion" - WD7, job posted 13/09/26

Building Vision London Ltd

£43/hour

£276/day

(last active 22/09/26)

Building Vision London Ltd is a trusted extension builder serving customers in London and the surrounding area. Contact us to today to get a compet...

"Single storey extension" - AL4, job posted 09/09/26

Claudiu Mihaila

£37/hour

£303/day

(last active 22/09/26)

Experienced extension builder ready to quote for your work. Claudiu Mihaila is the best extension builder in London. No obligation free quotes and ...

"Dormer loft extension" - RM13, job posted 08/09/26

Can design and Construction

£37/hour

£235/day

Member since August 2025

Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

"Loft conversion" - RM13, job posted 08/09/26

Torrington

£43/hour

£274/day

(last active 21/09/26)

NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...

"Speculative quote ahead of a prospective purchase" - E3, job posted 31/08/26

HOUSE BUILDING SERVICES LIMITED

£55/hour

£327/day

(last active 21/09/26)

HOUSE BUILDING SERVICES LIMITED is a trusted extension builder serving customers in London and the surrounding area. Contact us to today to get a c...

"New loft and side extension roof changing" - UB2, job posted 30/08/26

Red Box Maintenance Ltd

£45/hour

£282/day

(last active 21/09/26)

Red Box are a Fulham-based building and decorating business who work in West and Southwest London, and who specialise in fine interior renovations,...

"Loft conversion" - WD7, job posted 30/08/26

Greens Gardening & Landscape Property Maintenance

£42/hour

£268/day

(last active 21/09/26)

Watch our short video highlighting all our expertise and services here:

more than 10 y...

"New loft and side extension roof changing" - SOUTHALL, job posted 30/08/26

Mr

£33/hour

£262/day

(last active 21/09/26)

Experienced extension builder ready to quote for your work. Mr is the best extension builder in London. No obligation free quotes and many happy cu...

"Loft conversion" - RM14, job posted 26/08/26

Cre8tive Contractors Ltd

£39/hour

£249/day

(last active 21/09/26)

Cre8tive Contractors Ltd are here to help customers who need an Extension Builder in London. We offer a competitive rate to complete all your exten...

"Underpin a building" - N10, job posted 26/08/26

Saintflexs

£47/hour

£297/day

(last active 21/09/26)

Need an Extension Builder in London? Saintflexs has been helping local clients (10 mile radius) with their extension buildering jobs for many year...

"Underpin a building" - N7, job posted 23/08/26

AM Builder

£41/hour

£261/day

(last active 21/09/26)

Trusted and professional extension builder in London. Experienced in all extension buildering work and keeping within budget and on quote. AM Build...

"Porch construction on the side entrance of the house" - TW3, job posted 21/08/26

Derryard Construction Ltd

£44/hour

£275/day

(last active 21/09/26)

Relax... you have found a reliable extension builder in London. Derryard Construction Ltd is a friendly and reliable company based in London who co...

"Loft conversion" - HORNCHURCH, job posted 09/08/26

PFM General Building Services Ltd

£35/hour

£281/day

(last active 21/09/26)

Need to find an Extension Builder near you for all your extension buildering work?

PFM General Building Services Ltd provides a local, trus...

"Extension single room" - KT9, job posted 26/07/26

Charlie Builder

£44/hour

£280/day

(last active 21/09/26)

Trusted and professional extension builder in London. Experienced in all extension buildering work and keeping within budget and on quote. Charlie ...

"Single storey extension" - COULSDON, job posted 17/07/26

Gallant Contractors Ltd

£40/hour

£249/day

(last active 21/09/26)

Gallant Contractors have partnered with Homeowners, Designers and Architects to deliver unrivalled construction, renovation, double glazing and ref...

"Loft conversion" - EALING, job posted 25/06/26

Quickly find an Extension Builder in London

Use these steps to find Extension Builders in London for FREE!

  1. Post your job: Click "Get quotes" and briefly describe your job.
  2. Enter your details: We’ll match you with Extension Builders in London. We’ll notify you via text or email when an Extension Builder is available to quote.
  3. Select your Extension Builder: Compare Extension Builders  interested in working with you. You can use HaMuch to safely message local London Extension Builders or phone them directly - you’re in control!

The most important thing is do avoid handing over cash or paying large sums in advance. Be wary of paying cash for a cheaper job, i.e. to avoid VAT, you may be going down a slippery slope of not doing things properly which may eventually mean your job is also not done properly.

Agree when you intend to pay, ideally after you are satisfied with the completed job. If it is a big job agree a schedule of staged payments which is fair to both parties.

To avoid bad tradespeople and to ensure you can find them should they not answer a mobile;

  • Get proper contact details and check them yourself
  • Check if the company is verified on the Companies House website
  • Get phone details, ideally a land line or 0800 number and check it
  • Get a physical office address

Get quotes in writing by email or in person if possible. Getting quotes online or by text is ok (make sure you accept the offer by replying). For large projects make a written agreement, schedule of works and snagging plans as part of a working document. Also;

  • Agree expected quality of workmanship and materials in advance
  • When will work start and when will project be finished, what happens if project over runs ?
  • How long is the guarantee on work and materials eg 12 months
  • Discuss onsite behaviour in advance (no smoking, swearing or using mobile phones for non-work purposes)
  • Agree that your Extension Builder will remove all debris and rubbish and what level of tidying up you want after job

Compare London extension builders rates

Compare London extension builders rates
Location in UKHourly RateDaily Rate
Extension Builders near Belgravia£44£276
Extension Builders near Lambeth£44£275
Extension Builders near Camden Town£44£277
Extension Builders near Chelsea£44£276
Extension Builders near Islington£45£276
Extension Builders near Camberwell£44£276
Extension Builders near Kensington£44£277
Extension Builders near Bethnal Green£45£276
Extension Builders near Hackney£45£278
Extension Builders near Fulham£44£277
Extension Builders near Hammersmith£44£278
Extension Builders near Earlsfield£44£276
Extension Builders near Greenwich£44£268
Extension Builders near Muswell Hill£44£273
Extension Builders near Lewisham£43£268
Extension Builders near Wimbledon£43£271
Extension Builders near Plaistow£42£268
Extension Builders near Brent Cross£43£272
Extension Builders near Walthamstow£45£277
Extension Builders near Merton£43£272
Extension Builders near Ealing£44£275
Extension Builders near Redbridge£41£264
Extension Builders near Bromley£42£265
Extension Builders near Croydon£43£267
Extension Builders near Barking£43£261
Extension Builders near Kingston Upon Thames£43£271
Extension Builders near Sutton£43£273
Extension Builders near High Barnet£43£272
Extension Builders near Harrow£43£271
Extension Builders near Hounslow£43£281
Extension Builders near Richmond Upon Thames£43£274
Extension Builders near Bexley£42£265
Extension Builders near Hillingdon£63£276
Extension Builders near Romford£45£275

Job estimates from extension builders near you

Whether you’re looking to extend your kitchen with a side return extension or you want to convert your basement into a liveable space, read our cost guides to get an idea of how much each project costs before getting a more accurate quote from our database of reliable tradespeople.

More extensions & conversions cost guides...

People in London searching for a Extension Builder also viewed...

The Largest Database of UK Trade Rates

At HaMuch we know what tradespeople charge because we have the largest database of rates anywhere in the UK. If you want quotes for jobs at the right price for you, post your jobs with HaMuch and get your home improvements kickstarted straight away!