Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.8 (20 reviews)

Find affordable Oxhey extension builders now

Extension builders rates in Oxhey range from £31/hour £235/day (COMPLETE CIVIL ENGINEERING) to £50/hour £314/day (Mandala Building Services). To see prices and availability now for your job click green button.

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"Loft conversion" - WD7, job posted 30/08/26

"Two storey extension" - WD3, job posted 13/05/26

"Loft conversion" - WD19, job posted 07/05/26

"Loft conversion" - HARROW, job posted 04/04/26

"Outbuilding" - HA4, job posted 16/03/26

"Looking for a loft conversion with a flat shed dormer (1 bed and bathroom) i have plans which have been submitted so looking for quotes" - WD24, job posted 26/12/25

"Loft conversion" - WD24, job posted 07/12/25

"Side return extension" - WD18, job posted 09/10/25

"Loft conversion" - HARROW ON THE HILL, job posted 29/09/25

"Cost to build a single storey extension rear roughly 4x5 and build a dormer loft conversion with ceilings lowered to get height in loft on a terraced house." - HA4, job posted 17/09/25

"I am looking for quotes for a small rear extension on a terraced property in WD18, Watford. The extension will be built directly behind the existing kitchen and will house a toilet, stand-up shower, and a small hand basin. Existing Details: Existing Kitchen Width (internal): 2.01 metres ..." - WD18, job posted 07/08/25

"I am looking for quotes for a small rear extension on a terraced property in WD18, Watford. The extension will be built directly behind the existing kitchen and will house a toilet, stand-up shower, and a small hand basin. Existing Details: Property Type: Mid-terrace house Location: WD18,..." - WATFORD, job posted 07/08/25

"Garden office" - HARROW ON THE HILL, job posted 20/07/25

"Loft conversion" - HARROW ON THE HILL, job posted 05/07/25

"Single storey extension" - WATFORD, job posted 26/05/25

"Garage conversion" - PINNER, job posted 24/03/25

"Outbuilding" - HA4, job posted 11/03/25

"Loft conversion" - HARROW ON THE HILL, job posted 07/03/25

"Hip to gable loft conversion" - WD24, job posted 28/01/25

"Two storey extension" - HA7, job posted 13/01/25

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 Oxhey extension builders rates

Compare Oxhey extension builders rates (excluding VAT or callout charges)
Location in UK	Hourly Rate	Daily Rate
Extension Builders near Watford	£43	£280
Extension Builders near Bushey	£43	£278
Extension Builders near Rickmansworth	£43	£282
Extension Builders near Harrow	£43	£270
Extension Builders near Borehamwood	£42	£271
Extension Builders near Hillingdon	£43	£276
Extension Builders near Gerrards Cross	£43	£283
Extension Builders near Brent Cross	£43	£273
Extension Builders near High Barnet	£43	£272
Extension Builders near St Albans	£43	£272

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 - £26,184

Garden office - £10,184

Granny annexe - £87,184

Build a flat roof extension - £22,184

Convert a Garage - £16,184

Hip to gable loft conversion - £42,184

Convert a bungalow loft - £29,184

Build a dormer loft conversion - £42,184

Build a swimming pool - £81,184

Build a Mansard loft conversion - £52,184

Concrete foundations - £6,434

Underpin a building - £17,684

Two storey extension - £88,276

Convert a basement - £39,570

Side return extension - £43,570

Loft conversion - £35,475

Garage - £18,684

Single storey extension - £58,680

Outbuilding - £10,184

Install an RSJ - £2,384

Build a kitchen extension - £42,184

More extensions & conversions cost guides...

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