From £17,548
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in TN13. No obligation free quotes...
From £17,380
Experienced extension builder ready to quote for your work. CIA Construction Limited is the best extension builder in TN13. No obligation free quot...
From £17,564
Hyde Building Ltd are here to help customers who need an Extension Builder in TN13. We offer a competitive rate to complete all your extension buil...
From £18,524
Buci builders ltd is a trusted extension builder serving customers in TN13 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 TN13. Please contact us for a free, no obliga...
From £17,692
Gb construction are here to help customers who need an Extension Builder in TN13. 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 TN13. No obligation free quotes and ...
From £18,116
HOUSE BUILDING SERVICES LIMITED is a trusted extension builder serving customers in TN13 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...

Underpinning ranges from £17,380 (CIA Construction Limited based in RM18) 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 TN13 by posting a job with HaMuch and we will send it to extension builders in TN13.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Sevenoaks | £38 | £234 |
| Underpin A Building near Tonbridge | £38 | £254 |
| Underpin A Building near Tunbridge Wells | £37 | £258 |
| Underpin A Building near Bexley | £42 | £265 |
| Underpin A Building near Caterham | £43 | £272 |
| Underpin A Building near Larkfield | £41 | £253 |
| Underpin A Building near Bromley | £42 | £265 |
| Underpin A Building near Dartford | £51 | £273 |
| Underpin A Building near Croydon | £43 | £267 |
| Underpin A Building near Northfleet | £41 | £261 |
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 - £17,840

Two storey extension - £88,510

Build a timber frame extension - £26,340

Build a swimming pool - £81,340

Single storey extension - £61,800

Side return extension - £45,325

Install an RSJ - £2,540

Outbuilding - £10,340

Build a Mansard loft conversion - £52,340

Loft conversion - £36,938

Build a kitchen extension - £42,340

Hip to gable loft conversion - £42,340

Granny annexe - £87,340

Garden office - £10,340

Convert a Garage - £16,340

Garage - £18,840

Build a flat roof extension - £22,340

Build a dormer loft conversion - £42,340

Concrete foundations - £6,590

Convert a bungalow loft - £29,340

Convert a basement - £41,325