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 £17,468
Greater London, SW14
MCB Developments is an established extension buildering business in Mortlake. We come highly recommended and provide competitive quotes for your wo...
From £17,988
Metos Design & Build is a property renovation and bespoke kitchen company based in South West London. With two decades of experience and an excepti...
From £17,820
Mortlake Richmond Surrey, SW14
Gem Look Construction specialise in large refurbishments, extensions, loft conversions and more. Offering a full Design & Build service we are able...
From £17,564
Raylian Power Design are here to help customers who need an Extension Builder in Mortlake. We offer a competitive rate to complete all your extensi...
From £17,540
Mortlake Greater London, SW14
Our specialist and diverse skill sets include: concept design, design Illustration and detailing, layout drawings, project management, architectura...
From £17,652
Experienced extension builder ready to quote for your work. Build Space London Ltd is the best extension builder in Mortlake. No obligation free qu...
From £17,852
Greater London, SW14
Experienced extension builder ready to quote for your work. Convert Construction Ltd is the best extension builder in Mortlake. No obligation free ...
From £17,876
Need to find an Extension Builder near you for all your extension buildering work?
Family developments Ltd provides a local, trusted extens...
From £17,468
Need to find an Extension Builder near you for all your extension buildering work?
Embury Building Services Ltd provides a local, trusted e...

Underpinning ranges from £17,468 (MCB Developments based in SW14) to £17,988 (Metos Design & Build based in SW14), 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 Mortlake by posting a job with HaMuch and we will send it to extension builders in Mortlake.
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 - £17,671

Two storey extension - £88,257

Build a timber frame extension - £26,171

Build a swimming pool - £81,171

Single storey extension - £58,424

Side return extension - £43,426

Install an RSJ - £2,371

Outbuilding - £10,171

Build a Mansard loft conversion - £52,171

Loft conversion - £35,355

Build a kitchen extension - £42,171

Hip to gable loft conversion - £42,171

Granny annexe - £87,171

Garden office - £10,171

Convert a Garage - £16,171

Garage - £18,671

Build a flat roof extension - £22,171

Build a dormer loft conversion - £42,171

Concrete foundations - £6,421

Convert a bungalow loft - £29,171

Convert a basement - £39,426