Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.63 (16 reviews)

Find local affordable SN4 extension builders

Cheapest £26/hour & £185/day (MR HOWELL) to £39/hour & £289/day (The trade collective ltd) - average £32/hour & £239/day

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"Underpin a building" - SN3, job posted 05/09/26

"Main contractor required for the refurbishment of Laboratories 258 & 270 at the British Antarctic Survey, Cambridge. Works include internal strip-out, building alterations, partitioning, ceilings, flooring, decorating, mechanical and electrical installations, laboratory fit-out, fire stopping,..." - SN2, job posted 28/07/26

"Single storey extension" - SN2, job posted 17/07/26

"Two storey extension" - SN1, job posted 27/01/26

"Two storey extension" - SN2, job posted 27/01/26

"Garage conversion" - SWINDON, job posted 10/01/26

"Single storey extension" - SWINDON, job posted 24/10/25

"Loft conversion" - SWINDON, job posted 06/10/25

"Loft conversion" - SWINDON, job posted 16/02/25

"Loft conversion for 48 meter square house" - SN25, job posted 09/02/25

"RSJ installation" - SN2, job posted 19/11/24

"Loft conversion" - SWINDON, job posted 18/08/24

"Loft conversion" - SWINDON, job posted 12/06/24

"Loft conversion" - SWINDON, job posted 21/04/24

"Loft conversion end terrace house. Lift gable end on side, large dormer to the back Velex window to the front. Ensuite, and stairs from box room front to middle so head Hight already there." - SWINDON, job posted 08/02/24

"3x3m external size single story rear extension" - SN5, job posted 04/10/23

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 SN4 extension builders rates

Compare SN4 extension builders rates (excluding VAT or callout charges)
Location in UK	Hourly Rate	Daily Rate
Extension Builders near Swindon	£38	£238
Extension Builders near Stratton St Margaret	£37	£238
Extension Builders near Thamesdown	£38	£239
Extension Builders near Calne	£29	£225
Extension Builders near North Wiltshire	£32	£242
Extension Builders near West Wiltshire	£32	£242
Extension Builders near Devizes	£32	£242
Extension Builders near Vale of White Horse	£36	£271
Extension Builders near Chippenham	£34	£258
Extension Builders near Trowbridge	£34	£266

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 - £25,920

Garden office - £9,920

Granny annexe - £86,920

Build a flat roof extension - £21,920

Convert a Garage - £15,920

Hip to gable loft conversion - £41,920

Convert a bungalow loft - £28,920

Build a dormer loft conversion - £41,920

Build a swimming pool - £80,920

Build a Mansard loft conversion - £51,920

Concrete foundations - £6,170

Underpin a building - £17,420

Two storey extension - £87,880

Convert a basement - £36,600

Side return extension - £40,600

Loft conversion - £33,000

Garage - £18,420

Single storey extension - £53,400

Outbuilding - £9,920

Install an RSJ - £2,120

Build a kitchen extension - £41,920

More extensions & conversions cost guides...

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