Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.6 (20 reviews)

Find affordable London extension builders

Prices range from cheapest £30/hour and £235/day (Nisup Building Services) to £80/hour and £400/day (Banga Decoration) - average £44/hr and £280/day

HaMuch is Excellent

Local London extension builders & latest jobs

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

"For garden extention" - SM5, job posted 23/06/26

"Loft conversion quote" - EN5, job posted 20/06/26

"Loft conversion" - EN5, job posted 20/06/26

"Basement conversion" - SE18, job posted 18/06/26

"Outbuilding" - IG5, job posted 17/05/26

Quickly find an Extension Builder in London

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

Post your job: Click "Get quotes" and briefly describe your job.
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.
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!

What are the best ways to avoid problems when paying the Extension Builder?

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

Before the job starts should I agree standards of quality and behaviour?

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 UK	Hourly Rate	Daily 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	£276
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	£267
Extension Builders near Brent Cross	£43	£271
Extension Builders near Walthamstow	£45	£276
Extension Builders near Merton	£43	£272
Extension Builders near Ealing	£44	£274
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	£270
Extension Builders near Hounslow	£43	£281
Extension Builders near Richmond Upon Thames	£43	£273
Extension Builders near Bexley	£41	£265
Extension Builders near Hillingdon	£62	£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.

Build a timber frame extension - £26,184

Garden office - £10,184

Granny annexe - £87,184

Build a flat roof extension - £22,184

Convert a Garage - £16,184

Hip to gable loft conversion - £42,184

Convert a bungalow loft - £29,184

Build a dormer loft conversion - £42,184

Build a swimming pool - £81,184

Build a Mansard loft conversion - £52,184

Concrete foundations - £6,434

Underpin a building - £17,684

Two storey extension - £88,276

Convert a basement - £39,570

Side return extension - £43,570

Loft conversion - £35,475

Garage - £18,684

Single storey extension - £58,680

Outbuilding - £10,184

Install an RSJ - £2,384

Build a kitchen extension - £42,184

More extensions & conversions cost guides...

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

Painter and Decorator

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!

Appliance Repair Specialist

Conservatory Specialist