From £17,444
Ross Taylor Homes is an established extension buildering business in SG3. We come highly recommended and provide competitive quotes for your work.<...
From £17,460
Relax... you have found a reliable extension builder in SG3. Interior Installations is a friendly and reliable company based in SG3 who consider no...
From £17,420
Need an Extension Builder in SG3? MA Gower has been helping local clients (20 mile radius) with their extension buildering jobs for many years. Get...
From £17,908
Laurdan Building LTD is an established and experienced local extension builder in SG3. Please contact us for a free, no obligation quote and compet...
From £17,692
In an unstable market house extensions are often the most viable option, helping you to get the most out of the space you have without the addition...
From £17,596
Relax... you have found a reliable extension builder in SG3. GB Build is a friendly and reliable company based in SG3 who consider no job as too bi...
From £16,820
Complex Construction is an established extension buildering business in SG3. We come highly recommended and provide competitive quotes for your wor...
From £17,860
We are a family run business with over 30 years of combined experience, we offer everything from replacing doors and worktops on your kitchen to sm...
From £17,772
Harris Building Solutions Limited is an established extension buildering business in SG3. We come highly recommended and provide competitive quotes...
From £17,900
J&R Property is an established and experienced local extension builder in SG3. Please contact us for a free, no obligation quote and competitive ra...

Underpinning ranges from £16,820 (Complex Construction based in AL7) to £17,908 (Laurdan Building LTD based in AL6), 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 SG3 by posting a job with HaMuch and we will send it to extension builders in SG3.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Stevenage | £37 | £239 |
| Underpin A Building near Welwyn Garden City | £36 | £229 |
| Underpin A Building near Hertford | £39 | £247 |
| Underpin A Building near Hitchin | £37 | £238 |
| Underpin A Building near East Hertfordshire | £37 | £241 |
| Underpin A Building near North Hertfordshire | £37 | £239 |
| Underpin A Building near Hatfield | £53 | £244 |
| Underpin A Building near Ware | £40 | £252 |
| Underpin A Building near Harpenden | £70 | £264 |
| Underpin A Building near Letchworth | £37 | £239 |
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 - £17,587

Two storey extension - £88,131

Build a timber frame extension - £26,087

Build a swimming pool - £81,087

Single storey extension - £56,744

Side return extension - £42,481

Install an RSJ - £2,287

Outbuilding - £10,087

Build a Mansard loft conversion - £52,087

Loft conversion - £34,568

Build a kitchen extension - £42,087

Hip to gable loft conversion - £42,087

Granny annexe - £87,087

Garden office - £10,087

Convert a Garage - £16,087

Garage - £18,587

Build a flat roof extension - £22,087

Build a dormer loft conversion - £42,087

Concrete foundations - £6,337

Convert a bungalow loft - £29,087

Convert a basement - £38,481