Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.72 (9 reviews)

Find affordable SG1 extension builders

Extension builders rates in SG1 range from £38/hour £252/day (G B BUILDSTORE LTD) to £76/hour £313/day (Precision Roofing & Building Maintenance). To see prices and availability now for your job click green button.

HaMuch is Excellent

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"Kitchen extension" - HITCHIN, job posted 03/06/26

"Outbuilding" - SG2, job posted 01/06/26

"Can i get a builder for an extension quotation please - require 1first floor building on top of my garage and a revamped, heat-proof conservatory if you deal with this - reasonably priced please, thank you." - SG2, job posted 21/04/26

"Side return extension" - SG4, job posted 01/03/26

"Kitchen extension" - SG1, job posted 18/11/25

"Single storey extension" - STEVENAGE, job posted 08/11/25

"I would to build an extension on top of my garage, planning stage at the moment but I would like to have an experienced builders intake, realistic cost analysis with a plan to use the builder throughout too. Thanks." - SG2, job posted 04/06/25

"Front of house extension. End of terrace property." - SG2, job posted 30/04/25

"Single storey extension" - LETCHWORTH, job posted 30/05/24

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 SG1 extension builders rates

Compare SG1 extension builders rates (excluding VAT or callout charges)
Location in UK	Hourly Rate	Daily Rate
Extension Builders near Stevenage	£44	£282
Extension Builders near Hitchin	£43	£283
Extension Builders near North Hertfordshire	£44	£283
Extension Builders near Letchworth	£44	£283
Extension Builders near East Hertfordshire	£44	£289
Extension Builders near Welwyn Garden City	£42	£269
Extension Builders near Hertford	£46	£290
Extension Builders near Harpenden	£87	£317
Extension Builders near Luton	£42	£279
Extension Builders near Ware	£47	£296

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 - £26,272

Garden office - £10,272

Granny annexe - £87,272

Build a flat roof extension - £22,272

Convert a Garage - £16,272

Hip to gable loft conversion - £42,272

Convert a bungalow loft - £29,272

Build a dormer loft conversion - £42,272

Build a swimming pool - £81,272

Build a Mansard loft conversion - £52,272

Concrete foundations - £6,522

Underpin a building - £17,772

Two storey extension - £88,408

Convert a basement - £40,560

Side return extension - £44,560

Loft conversion - £36,300

Garage - £18,772

Single storey extension - £60,440

Outbuilding - £10,272

Install an RSJ - £2,472

Build a kitchen extension - £42,272

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