From £17,708
FEATHERBED CONSTRUCTION is a trusted extension builder serving customers in BS40 and the surrounding area. Contact us to today to get a competitive...
From £17,268
Trusted and professional extension builder in BS40. Experienced in all extension buildering work and keeping within budget and on quote. Jeremy Bly...
From £17,740
We are a full-service design and build company committed to creating sustainable and efficient buildings. We understand that a house is more than j...
From £17,716
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,444
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £18,428
We are a family run small business, we only use fully time served tradespeople. Having been building for 22years a still having a passion for quali...
From £17,748
Paskell Construction is an established and experienced local extension builder in BS40. Please contact us for a free, no obligation quote and compe...
From £17,260
Trusted and professional extension builder in BS40. Experienced in all extension buildering work and keeping within budget and on quote. L J Iles C...
From £17,500
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,340
MOORLAND DESIGN & BUILD LTD are here to help customers who need an Extension Builder in BS40. We offer a competitive rate to complete all your exte...

Underpinning ranges from £17,260 (L J Iles Construction based in BS25) to £18,428 (Unique Design & Build based in BS39), 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 BS40 by posting a job with HaMuch and we will send it to extension builders in BS40.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near North Somerset | £32 | £245 |
| Underpin A Building near Clifton | £33 | £255 |
| Underpin A Building near Bristol | £33 | £256 |
| Underpin A Building near Clevedon | £32 | £243 |
| Underpin A Building near Bath | £32 | £249 |
| Underpin A Building near Portishead | £33 | £247 |
| Underpin A Building near Keynsham | £33 | £251 |
| Underpin A Building near Weston-super-Mare | £33 | £253 |
| Underpin A Building near Kingswood | £34 | £257 |
| Underpin A Building near Bradley Stoke | £34 | £259 |
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 - £17,615

Two storey extension - £88,173

Build a timber frame extension - £26,115

Build a swimming pool - £81,115

Single storey extension - £57,304

Side return extension - £42,796

Install an RSJ - £2,315

Outbuilding - £10,115

Build a Mansard loft conversion - £52,115

Loft conversion - £34,830

Build a kitchen extension - £42,115

Hip to gable loft conversion - £42,115

Granny annexe - £87,115

Garden office - £10,115

Convert a Garage - £16,115

Garage - £18,615

Build a flat roof extension - £22,115

Build a dormer loft conversion - £42,115

Concrete foundations - £6,365

Convert a bungalow loft - £29,115

Convert a basement - £38,796