From £17,540
Hertfordshire, NW7
RAS Construction & Design Ltd is a well established company specialising in all aspects of extensions, loft conversions, general building, renovati...
From £17,348
Ask Windows Limited is an established and experienced local extension builder in NW7. Please contact us for a free, no obligation quote and competi...
From £17,652
Greater London, NW7
Trusted and professional extension builder in NW7. Experienced in all extension buildering work and keeping within budget and on quote. MH Costa Co...
From £17,500
TSCR Construction are here to help customers who need an Extension Builder in NW7. We offer a competitive rate to complete all your extension build...
From £16,908
London, NW7
DBR Construction Ltd are here to help customers who need an Extension Builder in NW7. We offer a competitive rate to complete all your extension bu...
From £17,868
NW London Contracts Ltd are here to help customers who need an Extension Builder in NW7. We offer a competitive rate to complete all your extension...
From £17,260
Hi everyone!
i have good experience over 25 years working in construction and I have my on Business and my company
From £17,164
With over 24 years of hands-on experience, FC Builders London Ltd specialises in home extensions, loft conversions, full renovations, kitchen and b...
From £17,892
Greater London, NW7
Coldshield ltd are here to help customers who need an Extension Builder in NW7. We offer a competitive rate to complete all your extension builderi...
From £17,420
NISUP BUILDING SERVICES Company specializes in the domestic and commercial building industry :1. Refurbishm...

Underpinning ranges from £16,908 (DBR Construction Ltd based in NW7) to £17,892 (Coldshield ltd based in NW7), but the final cost will depend on the method of underpinning used, how much of your foundations need underpinning and where you live.
Comparing extension builders estimates for underpinning gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
Get quotes to underpin your home in NW7 by posting a job with HaMuch and we will send it to extension builders in NW7.
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.

Underpin a building - £17,455

Two storey extension - £87,933

Build a timber frame extension - £25,955

Build a swimming pool - £80,955

Single storey extension - £54,104

Side return extension - £40,996

Install an RSJ - £2,155

Outbuilding - £9,955

Build a Mansard loft conversion - £51,955

Loft conversion - £33,330

Build a kitchen extension - £41,955

Hip to gable loft conversion - £41,955

Granny annexe - £86,955

Garden office - £9,955

Convert a Garage - £15,955

Garage - £18,455

Build a flat roof extension - £21,955

Build a dormer loft conversion - £41,955

Concrete foundations - £6,205

Convert a bungalow loft - £28,955

Convert a basement - £36,996