From £17,340
Building services with over 10 years experience all work completed to the highest standard call for a quote.
From £17,676
JKS Property is an established and experienced local extension builder in PO1. Please contact us for a free, no obligation quote and competitive ra...
From £17,420
Relax... you have found a reliable extension builder in PO1. IndieGo Build is a friendly and reliable company based in PO1 who consider no job as t...
From £17,492
BUILD PROJECT LIMITED are here to help customers who need an Extension Builder in PO1. We offer a competitive rate to complete all your extension b...
From £17,396
Abacus Building Services is an established and experienced local extension builder in PO1. Please contact us for a free, no obligation quote and co...
From £17,516
Need an Extension Builder in PO1? Buildtech southern Ltd has been helping local clients (20 mile radius) with their extension buildering jobs for m...
From £17,508
ARCHIBUILD design, build and deliver exciting design driven projects for clients who share our passion for spaces and places that benefit people.We...
From £17,500
Experienced extension builder ready to quote for your work. Pompey Homes Ltd is the best extension builder in PO1. No obligation free quotes and ma...
From £17,468
Experienced extension builder ready to quote for your work. Shepperd Developments is the best extension builder in PO1. No obligation free quotes a...
From £17,316
Architectural services, Design of office ,hotel, transport building,Residential .From Conceptual work to Appication.

Underpinning ranges from £17,316 (SODCON based in PO2) to £17,676 (JKS Property based in PO5), 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 PO1 by posting a job with HaMuch and we will send it to extension builders in PO1.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Portsmouth | £36 | £248 |
| Underpin A Building near Gosport | £35 | £246 |
| Underpin A Building near Lee-on-the-Solent | £35 | £249 |
| Underpin A Building near Fareham | £35 | £250 |
| Underpin A Building near Havant & Waterloo | £35 | £245 |
| Underpin A Building near Havant | £34 | £245 |
| Underpin A Building near Waterlooville | £35 | £246 |
| Underpin A Building near Horndean | £35 | £248 |
| Underpin A Building near Locks Heath | £33 | £240 |
| Underpin A Building near Isle of Wight | £34 | £246 |
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 - £17,463

Two storey extension - £87,945

Build a timber frame extension - £25,963

Build a swimming pool - £80,963

Single storey extension - £54,264

Side return extension - £41,086

Install an RSJ - £2,163

Outbuilding - £9,963

Build a Mansard loft conversion - £51,963

Loft conversion - £33,405

Build a kitchen extension - £41,963

Hip to gable loft conversion - £41,963

Granny annexe - £86,963

Garden office - £9,963

Convert a Garage - £15,963

Garage - £18,463

Build a flat roof extension - £21,963

Build a dormer loft conversion - £41,963

Concrete foundations - £6,213

Convert a bungalow loft - £28,963

Convert a basement - £37,086