From £17,588
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,604
We are a part of the award-winning Refresh Renovation franchise network.Whether you want a simple bathroom remodel, or a large double storey extens...
From £17,564
Probuild was set up as a platform to service clients with High End affordable quality Construction & project Management with solid advice & accurat...
From £17,604
Need an Extension Builder in St Austell? Paul Clarke Architectural Builders has been helping local clients (20 mile radius) with their extension bu...
From £17,340
Aston Construction Project Management is a trusted extension builder serving customers in St Austell and the surrounding area. Contact us to today ...
From £17,436
SANDSTONE BUILDERS T/A is a trusted extension builder serving customers in St Austell and the surrounding area. Contact us to today to get a compet...
From £17,324
Relax... you have found a reliable extension builder in St Austell. BUILDMARK BUILDERS is a friendly and reliable company based in St Austell who c...
From £17,644
Relax... you have found a reliable extension builder in St Austell. Daniel Job Building & Roofing Contractor Ltd is a friendly and reliable company...
From £17,308
Need to find an Extension Builder near you for all your extension buildering work?
Pendragon Builders Ltd provides a local, trusted extensi...
From £17,460
Pendragon Builders is a Cornwall-based business with over 40 years of experience specializing in end-to-end building solutions. We specialise in e...

Underpinning ranges from £17,308 (Pendragon Builders Ltd based in PL26) to £17,644 (Daniel Job Building & Roofing Contractor Ltd based in PL24), 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 St Austell by posting a job with HaMuch and we will send it to extension builders in St Austell.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near St Austell | £38 | £245 |
| Underpin A Building near Truro | £31 | £206 |
| Underpin A Building near Newquay | £32 | £230 |
| Underpin A Building near Falmouth | £33 | £220 |
| Underpin A Building near Camborne | £28 | £196 |
| Underpin A Building near Plymouth | £30 | £230 |
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 - £17,487

Two storey extension - £87,981

Build a timber frame extension - £25,987

Build a swimming pool - £80,987

Single storey extension - £54,744

Side return extension - £41,356

Install an RSJ - £2,187

Outbuilding - £9,987

Build a Mansard loft conversion - £51,987

Loft conversion - £33,630

Build a kitchen extension - £41,987

Hip to gable loft conversion - £41,987

Granny annexe - £86,987

Garden office - £9,987

Convert a Garage - £15,987

Garage - £18,487

Build a flat roof extension - £21,987

Build a dormer loft conversion - £41,987

Concrete foundations - £6,237

Convert a bungalow loft - £28,987

Convert a basement - £37,356