From £17,156
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,324
Experienced extension builder ready to quote for your work. CR BUILDING & MAINTENANCE SERV is the best extension builder in SA18. No obligation fre...
From £17,500
GAB BUILDING CONTRACTORS LTD is an established and experienced local extension builder in SA18. Please contact us for a free, no obligation quote a...
From £17,468
S H PHILLIPS BUILDING CONTRACT are here to help customers who need an Extension Builder in SA18. We offer a competitive rate to complete all your e...
From £17,236
Trusted and professional extension builder in SA18. Experienced in all extension buildering work and keeping within budget and on quote. R E Davies...
From £17,476
Relax... you have found a reliable extension builder in SA18. OSBORNE BUILDING SERVICES is a friendly and reliable company based in SA18 who consid...
From £17,508
Experienced extension builder ready to quote for your work. D J Howells is the best extension builder in SA18. No obligation free quotes and many h...
From £16,692
I have 26 years experience in the building industry and owned my company for 24 years, i am able to carry out most buildin...
From £16,956
The Home Extension Company has earned its reputation as being one of the leading Home Development Companies in and around South Wales. We pride our...
From £17,172
SC CONSTRUCTION is an established and experienced local extension builder in SA18. Please contact us for a free, no obligation quote and competitiv...

Underpinning ranges from £16,692 (R i daniels based in SA14) to £17,508 (D J Howells based in SA18), 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 SA18 by posting a job with HaMuch and we will send it to extension builders in SA18.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Gorseinon | £25 | £196 |
| Underpin A Building near Neath | £25 | £191 |
| Underpin A Building near Llanelli | £25 | £196 |
| Underpin A Building near Neath Port Talbot | £26 | £188 |
| Underpin A Building near Swansea | £25 | £197 |
| Underpin A Building near Carmarthen | £24 | £191 |
| Underpin A Building near Carmarthenshire | £24 | £191 |
| Underpin A Building near Port Talbot | £26 | £188 |
| Underpin A Building near Maesteg | £32 | £239 |
| Underpin A Building near Pyle | £30 | £234 |
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 - £17,249

Two storey extension - £87,623

Build a timber frame extension - £25,749

Build a swimming pool - £80,749

Single storey extension - £49,976

Side return extension - £38,674

Install an RSJ - £1,949

Outbuilding - £9,749

Build a Mansard loft conversion - £51,749

Loft conversion - £31,395

Build a kitchen extension - £41,749

Hip to gable loft conversion - £41,749

Granny annexe - £86,749

Garden office - £9,749

Convert a Garage - £15,749

Garage - £18,249

Build a flat roof extension - £21,749

Build a dormer loft conversion - £41,749

Concrete foundations - £5,999

Convert a bungalow loft - £28,749

Convert a basement - £34,674