Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.63 (20 reviews)

Find affordable SN25 extension builders

Extension builders rates in SN25 range from £20/hour £182/day (Watts Builders) to £38/hour £280/day (Biocraft South West Ltd). To see prices and availability now for your job click green button.

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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

"Dormer loft conversion" - SN26, job posted 05/07/25

"Need an extension builder" - SN5, job posted 03/05/25

"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

"Fantastic service from start to finish. Great company, always fair" - SWINDON,reviewed 29/09/17, MARIE

"Concrete foundation for a future garage on the current drive way. 7x2.8 metres." - SN5, job posted 27/06/24

"Side return extension" - SN3, job posted 16/06/24

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

"Side return extension" - SN3, job posted 19/05/24

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

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 SN25 extension builders rates

Compare SN25 extension builders rates (excluding VAT or callout charges)
Location in UK	Hourly Rate	Daily Rate
Extension Builders near Thamesdown	£31	£239
Extension Builders near Stratton St Margaret	£32	£238
Extension Builders near Swindon	£31	£238
Extension Builders near Calne	£29	£225
Extension Builders near Vale of White Horse	£36	£271
Extension Builders near West Wiltshire	£32	£242
Extension Builders near North Wiltshire	£32	£242
Extension Builders near Witney	£32	£244
Extension Builders near Chippenham	£34	£258
Extension Builders near Devizes	£32	£242

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 - £25,896

Garden office - £9,896

Granny annexe - £86,896

Build a flat roof extension - £21,896

Convert a Garage - £15,896

Hip to gable loft conversion - £41,896

Convert a bungalow loft - £28,896

Build a dormer loft conversion - £41,896

Build a swimming pool - £80,896

Build a Mansard loft conversion - £51,896

Concrete foundations - £6,146

Underpin a building - £17,396

Two storey extension - £87,844

Convert a basement - £36,330

Side return extension - £40,330

Loft conversion - £32,775

Garage - £18,396

Single storey extension - £52,920

Outbuilding - £9,896

Install an RSJ - £2,096

Build a kitchen extension - £41,896

More extensions & conversions cost guides...

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