From £18,524
Buci builders ltd is a trusted extension builder serving customers in DA13 and the surrounding area. Contact us to today to get a competitive quote...
From £17,812
Local Boiler Plumbing & Heating Services is an established and experienced local extension builder in DA13. Please contact us for a free, no obliga...
From £17,692
Gb construction are here to help customers who need an Extension Builder in DA13. We offer a competitive rate to complete all your extension build...
From £18,700
Member since August 2025
Banga decoration. Is Base in south London for number of year Banga decoration is a small company. Wich provide an excellent job to the custom...
From £17,684
Experienced extension builder ready to quote for your work. CC&D BUILDING LTD is the best extension builder in DA13. No obligation free quotes and ...
From £18,116
HOUSE BUILDING SERVICES LIMITED is a trusted extension builder serving customers in DA13 and the surrounding area. Contact us to today to get a com...
From £17,380
Member since August 2025
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,420
Masonic Plumbing and Heating Ltd are here to help customers who need an Extension Builder in DA13. We offer a competitive rate to complete all your...
From £17,812
skilled worker who specializes in completing a wide range of building and renovation projects
From £17,700
Relax... you have found a reliable extension builder in DA13. Derryard Construction Ltd is a friendly and reliable company based in DA13 who consid...

Underpinning ranges from £17,380 (Can design and Construction based in Ig11) to £18,700 (Banga Decoration based in CR7), 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 DA13 by posting a job with HaMuch and we will send it to extension builders in DA13.
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 - £17,884

Two storey extension - £88,576

Build a timber frame extension - £26,384

Build a swimming pool - £81,384

Single storey extension - £62,680

Side return extension - £45,820

Install an RSJ - £2,584

Outbuilding - £10,384

Build a Mansard loft conversion - £52,384

Loft conversion - £37,350

Build a kitchen extension - £42,384

Hip to gable loft conversion - £42,384

Granny annexe - £87,384

Garden office - £10,384

Convert a Garage - £16,384

Garage - £18,884

Build a flat roof extension - £22,384

Build a dormer loft conversion - £42,384

Concrete foundations - £6,634

Convert a bungalow loft - £29,384

Convert a basement - £41,820