From £17,484
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,892
Eagle Eye Building has been helping customers in New Malden and the surrounding area by providing professional, trustworthy building services.
From £17,428
WILDE BUILDING CONTRACTORS LTD is an established extension buildering business in New Malden. We come highly recommended and provide competitive qu...
From £17,932
Trusted and professional extension builder in New Malden. Experienced in all extension buildering work and keeping within budget and on quote. Gord...
From £17,532
Relax... you have found a reliable extension builder in New Malden. Galaxy Extend is a friendly and reliable company based in New Malden who consid...
From £17,788
Linkfern Limited is an established extension buildering business in New Malden. We come highly recommended and provide competitive quotes for your ...
From £17,612
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,636
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,748
Trusted and professional extension builder in New Malden. Experienced in all extension buildering work and keeping within budget and on quote. Racs...
From £17,764
Need to find an Extension Builder near you for all your extension buildering work?
Racsel Building Services Ltd provides a local, trusted e...

Underpinning ranges from £17,428 (WILDE BUILDING CONTRACTORS LTD based in KT3) to £17,932 (Gordon Dicks based in KT3), 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 New Malden by posting a job with HaMuch and we will send it to extension builders in New Malden.
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 - £17,682

Two storey extension - £88,272

Build a timber frame extension - £26,182

Build a swimming pool - £81,182

Single storey extension - £58,632

Side return extension - £43,543

Install an RSJ - £2,382

Outbuilding - £10,182

Build a Mansard loft conversion - £52,182

Loft conversion - £35,453

Build a kitchen extension - £42,182

Hip to gable loft conversion - £42,182

Granny annexe - £87,182

Garden office - £10,182

Convert a Garage - £16,182

Garage - £18,682

Build a flat roof extension - £22,182

Build a dormer loft conversion - £42,182

Concrete foundations - £6,432

Convert a bungalow loft - £29,182

Convert a basement - £39,543