Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.7 (5 reviews)

Find affordable Cwmbran extension builders

Prices range from cheapest £20/hour and £150/day (A.Gaddarn Builders) to £40/hour and £288/day (Carter Thomas Construction Ltd) - average £32/hr and £221/day

HaMuch is Excellent

Local Cwmbran extension builders & latest jobs

"Loft conversion" - NP44, job posted 29/06/26

"Attic is already converted, but looking to alter to make space more useable. Potentially consider dormer or dormer windows and fitted storage." - NP18, job posted 30/12/25

"Loft conversion" - NEWPORT, job posted 06/03/25

"RSJ installation" - NEWPORT, job posted 16/10/24

"Remove current conservatory and build a small extension 4x4m" - NP19, job posted 01/05/24

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 Cwmbran extension builders rates

Compare Cwmbran extension builders rates (excluding VAT or callout charges)
Location in UK	Hourly Rate	Daily Rate
Extension Builders near Cwmbran	£43	£219
Extension Builders near Risca	£32	£218
Extension Builders near Newport	£41	£233
Extension Builders near Pontypool	£30	£210
Extension Builders near Caerphilly	£33	£208
Extension Builders near Ebbw Vale	£28	£218
Extension Builders near Tredegar	£28	£218
Extension Builders near Cardiff	£34	£219
Extension Builders near Pontypridd	£33	£211
Extension Builders near Church Village	£34	£214

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 - £25,800

Garden office - £9,800

Granny annexe - £86,800

Build a flat roof extension - £21,800

Convert a Garage - £15,800

Hip to gable loft conversion - £41,800

Convert a bungalow loft - £28,800

Build a dormer loft conversion - £41,800

Build a swimming pool - £80,800

Build a Mansard loft conversion - £51,800

Concrete foundations - £6,050

Underpin a building - £17,300

Two storey extension - £87,700

Convert a basement - £35,250

Side return extension - £39,250

Loft conversion - £31,875

Garage - £18,300

Single storey extension - £51,000

Outbuilding - £9,800

Install an RSJ - £2,000

Build a kitchen extension - £41,800

More extensions & conversions cost guides...

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