Name: Extension Builder
Brand: HaMuch
SKU: extension-renovation
Rating: 4.62 (13 reviews)

Find affordable Portsmouth extension builders

Prices range from cheapest £29/hour and £216/day (P Pattison) to £39/hour and £387/day (Devscapes) - average £35/hr and £252/day

HaMuch is Excellent

Local Portsmouth extension builders, reviews & latest jobs

"Garden office" - PO9, job posted 05/01/26

"Two storey extension" - PO12, job posted 30/09/25

"Single storey extension" - GOSPORT, job posted 21/07/25

"Two storey extension" - PORTSMOUTH, job posted 08/07/25

"RSJ installation" - PO2, job posted 25/11/24

"Loft conversion" - PORTSMOUTH, job posted 06/11/24

"Garage 5 metre by 4.7" - PORTSMO, job posted 28/09/24

"Loft conversion" - PORTSMOUTH, job posted 14/09/24

"Loft conversion" - PORTSMOUTH, job posted 19/08/24

"Loft conversion" - PORTSMOUTH, job posted 29/07/24

"Loft conversion: I am asking for to have loft conversion done to my house which has 3 bedrooms. It is a mid terraced house. What I am looking for is to build 2 big bedrooms in the loft and to have with fitted wardrobes in both of the rooms as well make extra storage units too and also to build a..." - PORTSMOUTH, job posted 11/04/24

"Loft conversion in my bunglow. No plans" - PORTSMOUTH, job posted 03/10/23

"Loft conversion" - PORTSMOUTH, job posted 09/08/23

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 Portsmouth extension builders rates

Compare Portsmouth extension builders rates (excluding VAT or callout charges)
Location in UK	Hourly Rate	Daily Rate
Extension Builders near Portsmouth	£36	£250
Extension Builders near Gosport	£35	£246
Extension Builders near Fareham	£35	£250
Extension Builders near Lee-on-the-Solent	£35	£249
Extension Builders near Havant & Waterloo	£35	£248
Extension Builders near Havant	£35	£249
Extension Builders near Waterlooville	£36	£250
Extension Builders near Horndean	£35	£253
Extension Builders near Ryde	£34	£255
Extension Builders near Locks Heath	£33	£240

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 - £25,984

Garden office - £9,984

Granny annexe - £86,984

Build a flat roof extension - £21,984

Convert a Garage - £15,984

Hip to gable loft conversion - £41,984

Convert a bungalow loft - £28,984

Build a dormer loft conversion - £41,984

Build a swimming pool - £80,984

Build a Mansard loft conversion - £51,984

Concrete foundations - £6,234

Underpin a building - £17,484

Two storey extension - £87,976

Convert a basement - £37,320

Side return extension - £41,320

Loft conversion - £33,600

Garage - £18,484

Single storey extension - £54,680

Outbuilding - £9,984

Install an RSJ - £2,184

Build a kitchen extension - £41,984

More extensions & conversions cost guides...

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