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 £17,508
Whites Carpentry & Building prides in delivering an excellent extension buildering service and value for money in Felpham and the surrounding areas...
From £18,596
We are a Small Family run business with over 30 years experience in the building trade, Carpentry is my main trade, with NVQ Level 2.
From £17,372
Need an Extension Builder in Felpham? MPS Home Improvements Ltd has been helping local clients (20 mile radius) with their extension buildering job...
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 £17,612
, BN18
Futureways Design and Build are here to help customers who need an Extension Builder in Felpham. We offer a competitive rate to complete all your e...
From £17,252
Park Building Services Ltd is a trusted extension builder serving customers in Felpham and the surrounding area. Contact us to today to get a compe...
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 £17,876
Giles Dixon is an experienced Project Manager with over 30 years experience, having worked from the ground up starting in 1984 as an apprentice ele...
From £17,628
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

Underpinning ranges from £17,252 (Park Building Services Ltd based in PO9) to £18,596 (R&B Property Improvements based in PO9), 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 Felpham by posting a job with HaMuch and we will send it to extension builders in Felpham.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Bognor Regis | £35 | £247 |
| Underpin A Building near Arun | £35 | £241 |
| Underpin A Building near Littlehampton | £35 | £244 |
| Underpin A Building near Chichester | £34 | £242 |
| Underpin A Building near Rustington | £36 | £246 |
| Underpin A Building near Worthing | £35 | £251 |
| Underpin A Building near Lancing | £37 | £251 |
| Underpin A Building near Havant & Waterloo | £35 | £248 |
| Underpin A Building near Havant | £35 | £249 |
| Underpin A Building near Shoreham-by-Sea | £36 | £250 |
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 - £17,698

Two storey extension - £88,296

Build a timber frame extension - £26,198

Build a swimming pool - £81,198

Single storey extension - £58,952

Side return extension - £43,723

Install an RSJ - £2,398

Outbuilding - £10,198

Build a Mansard loft conversion - £52,198

Loft conversion - £35,603

Build a kitchen extension - £42,198

Hip to gable loft conversion - £42,198

Granny annexe - £87,198

Garden office - £10,198

Convert a Garage - £16,198

Garage - £18,698

Build a flat roof extension - £22,198

Build a dormer loft conversion - £42,198

Concrete foundations - £6,448

Convert a bungalow loft - £29,198

Convert a basement - £39,723