From £17,708
Need to find an Extension Builder near you for all your extension buildering work?
JAYEM BUILDING SERVICES LTD provides a local, trusted ex...
From £17,700
TB Projects is an established extension buildering business in HP9. We come highly recommended and provide competitive quotes for your work.
From £17,460
Relax... you have found a reliable extension builder in HP9. Kebbell Development Limited is a friendly and reliable company based in HP9 who consid...
From £17,844
Be Illuminated are here to help customers who need an Extension Builder in HP9. We offer a competitive rate to complete all your extension builderi...
From £17,812
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,404
Belvedere is an established and experienced local extension builder in HP9. Please contact us for a free, no obligation quote and competitive rates...
From £17,660
Need to find an Extension Builder near you for all your extension buildering work?
Loudwater Building Services provides a local, trusted ex...
From £17,836
Relax... you have found a reliable extension builder in HP9. J MCNAMEE J & J BUILDERS is a friendly and reliable company based in HP9 who consider ...
From £17,676
Experienced extension builder ready to quote for your work. G C JONES CONSTRUCTION CO LTD is the best extension builder in HP9. No obligation free ...
From £17,900
E E Construction is an established extension buildering business in HP9. We come highly recommended and provide competitive quotes for your work.

Underpinning ranges from £17,404 (Belvedere based in HP10) to £17,900 (E E Construction based in HP10), 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 HP9 by posting a job with HaMuch and we will send it to extension builders in HP9.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Gerrards Cross | £37 | £244 |
| Underpin A Building near Hazlemere | £34 | £235 |
| Underpin A Building near High Wycombe | £34 | £237 |
| Underpin A Building near Slough | £36 | £238 |
| Underpin A Building near Maidenhead | £36 | £236 |
| Underpin A Building near Rickmansworth | £37 | £241 |
| Underpin A Building near Chesham | £36 | £237 |
| Underpin A Building near Wycombe | £34 | £234 |
| Underpin A Building near Windsor & Maidenhead | £36 | £238 |
| Underpin A Building near Hillingdon | £56 | £240 |
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 - £17,700

Two storey extension - £88,300

Build a timber frame extension - £26,200

Build a swimming pool - £81,200

Single storey extension - £59,000

Side return extension - £43,750

Install an RSJ - £2,400

Outbuilding - £10,200

Build a Mansard loft conversion - £52,200

Loft conversion - £35,625

Build a kitchen extension - £42,200

Hip to gable loft conversion - £42,200

Granny annexe - £87,200

Garden office - £10,200

Convert a Garage - £16,200

Garage - £18,700

Build a flat roof extension - £22,200

Build a dormer loft conversion - £42,200

Concrete foundations - £6,450

Convert a bungalow loft - £29,200

Convert a basement - £39,750