Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.61 (19 reviews)

Find affordable Cosgrove extension builders

Prices range from cheapest £29/hour and £223/day (A B Construction) to £46/hour and £312/day (JAB) - average £38/hr and £261/day

HaMuch is Excellent

Local Cosgrove extension builders, reviews & latest jobs

"Two single bedroom" - MK8, job posted 22/06/26

"Kitchen extension" - MILTON KEYNES, job posted 05/02/26

"Loft conversion" - MILTON KEYNES, job posted 14/08/25

"Kitchen extension" - MILTON KEYNES, job posted 30/05/25

"Garage conversion" - MILTON KEYNES, job posted 25/05/25

"First floor extension" - MK12, job posted 23/05/25

"Kitchen extension" - MILTON KEYNES, job posted 08/04/25

"Garage conversion to a kitchen" - MILTON KEYNES, job posted 25/03/25

"Garage conversion" - MILTON KEYNES, job posted 25/03/25

"Single storey extension" - MILTON KEYNES, job posted 22/02/25

"Loft conversion" - MILTON KEYNES, job posted 17/12/24

"Loft conversion" - MILTON KEYNES, job posted 18/07/24

"Loft conversion" - MILTON KEYNES, job posted 09/07/24

"Internal supporting wall needs removing (3.5m wide) and RSJ installed above plinths within ceiling." - MK19, job posted 19/06/24

"Loft conversion" - MILTON KEYNES, job posted 07/05/24

"Loft conversion" - MILTON KEYNES, job posted 23/04/24

"Loft conversion Velux conversion" - MILTON KEYNES, job posted 29/12/23

"Loft conversion" - MILTON KEYNES, job posted 27/09/23

"Loft conversion" - MILTON KEYNES, job posted 28/08/23

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 Cosgrove extension builders rates

Compare Cosgrove extension builders rates (excluding VAT or callout charges)
Location in UK	Hourly Rate	Daily Rate
Extension Builders near Milton Keynes	£39	£263
Extension Builders near Bletchley	£39	£265
Extension Builders near Northampton	£35	£239
Extension Builders near Aylesbury Vale	£36	£246
Extension Builders near Leighton Buzzard	£38	£270
Extension Builders near Ampthill	£38	£258
Extension Builders near Kempston	£44	£273
Extension Builders near Bedford	£45	£278
Extension Builders near South Bedfordshire	£45	£278
Extension Builders near Mid Bedfordshire	£42	£276

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 - £26,112

Garden office - £10,112

Granny annexe - £87,112

Build a flat roof extension - £22,112

Convert a Garage - £16,112

Hip to gable loft conversion - £42,112

Convert a bungalow loft - £29,112

Build a dormer loft conversion - £42,112

Build a swimming pool - £81,112

Build a Mansard loft conversion - £52,112

Concrete foundations - £6,362

Underpin a building - £17,612

Two storey extension - £88,168

Convert a basement - £38,760

Side return extension - £42,760

Loft conversion - £34,800

Garage - £18,612

Single storey extension - £57,240

Outbuilding - £10,112

Install an RSJ - £2,312

Build a kitchen extension - £42,112

More extensions & conversions cost guides...

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