From £17,940
Need to find an Extension Builder near you for all your extension buildering work?
Main Construction provides a local, trusted extension bu...
From £17,372
Need an Extension Builder in Southwick? MPS Home Improvements Ltd has been helping local clients (20 mile radius) with their extension buildering j...
From £17,492
Member since August 2026
H P Building Services Sussex is a one-stop solution for all your extension buildering needs. Establish over 10 years ago and covering 20 miles arou...
From £17,532
We are a family run business we 40 years experience delivering multiple projects from new developments . Extension. Loft conversion. Including foun...
From £17,612
Futureways Design and Build are here to help customers who need an Extension Builder in Southwick. We offer a competitive rate to complete all your...
From £17,700
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,380
Trusted and professional extension builder in Southwick. Experienced in all extension buildering work and keeping within budget and on quote. Stret...
From £17,228
Need to find an Extension Builder near you for all your extension buildering work?
Knights Construction provides a local, trusted extension...
From £17,268
Trusted and professional extension builder in Southwick. Experienced in all extension buildering work and keeping within budget and on quote. Paul ...
From £17,484
Need to find an Extension Builder near you for all your extension buildering work?
FMB CONSTRUCTION LTD provides a local, trusted extension...

Underpinning ranges from £17,228 (Knights Construction based in BN18) to £17,940 (Main Construction based in BN12), 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 Southwick by posting a job with HaMuch and we will send it to extension builders in Southwick.
"Underpinning" - BRIGHTON, job posted 01/01/70
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Shoreham-by-Sea | £36 | £250 |
| Underpin A Building near Lancing | £37 | £251 |
| Underpin A Building near Brighton | £35 | £251 |
| Underpin A Building near Brighton and Hove | £35 | £251 |
| Underpin A Building near Worthing | £35 | £251 |
| Underpin A Building near Burgess Hill | £36 | £240 |
| Underpin A Building near Rustington | £36 | £246 |
| Underpin A Building near Haywards Heath | £35 | £256 |
| Underpin A Building near Littlehampton | £35 | £244 |
| Underpin A Building near Mid Sussex | £35 | £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 - £17,501

Two storey extension - £88,001

Build a timber frame extension - £26,001

Build a swimming pool - £81,001

Single storey extension - £55,016

Side return extension - £41,509

Install an RSJ - £2,201

Outbuilding - £10,001

Build a Mansard loft conversion - £52,001

Loft conversion - £33,758

Build a kitchen extension - £42,001

Hip to gable loft conversion - £42,001

Granny annexe - £87,001

Garden office - £10,001

Convert a Garage - £16,001

Garage - £18,501

Build a flat roof extension - £22,001

Build a dormer loft conversion - £42,001

Concrete foundations - £6,251

Convert a bungalow loft - £29,001

Convert a basement - £37,509