From £22,040
Hertfordshire, NW7
RAS Construction & Design Ltd is a well established company specialising in all aspects of extensions, loft conversions, general building, renovati...
From £21,848
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 £22,152
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 £22,000
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 £21,408
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 £22,368
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 £21,760
Hi everyone!
i have good experience over 25 years working in construction and I have my on Business and my company
From £21,664
With over 24 years of hands-on experience, FC Builders London Ltd specialises in home extensions, loft conversions, full renovations, kitchen and b...
From £22,392
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 £21,920
NISUP BUILDING SERVICES Company specializes in the domestic and commercial building industry :1. Refurbishm...

A flat roof extension ranges from the cheapest of £21,408 (DBR Construction Ltd based in NW7) to the dearest of £22,392 (Coldshield ltd based in NW7), but these are just estimates. While they give you an idea of who will be better value, the best way to compare costs is to get real quotes.
Find out how much your flat roof extension will cost in NW7 by posting a job with HaMuch. We'll 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