From £18,060
Our homes need to be regularly maintained and from time to time they need to be rejuvenated, modernised and enhanced. When it comes to building wor...
From £17,892
Need an Extension Builder in Welwyn? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many ...
From £19,084
Propello is an established and experienced local extension builder in Welwyn. Please contact us for a free, no obligation quote and competitive ra...
From £17,924
Sharp Building Ltd is an established and experienced local extension builder in Welwyn. Please contact us for a free, no obligation quote and compe...
From £17,420
NISUP BUILDING SERVICES Company specializes in the domestic and commercial building industry :1. Refurbishm...
From £17,732
If you are looking for a Welwyn extension builder and you need something replaced, fitted, or fixed, contact Space Above Limited today. We are comp...
From £17,724
S Cooke Building Services is an established and experienced local extension builder in Welwyn. Please contact us for a free, no obligation quote an...
From £17,924
Nouvell Decor is a trusted extension builder serving customers in Welwyn and the surrounding area. Contact us to today to get a competitive quote f...
From £17,932
Platinum Electrics is a Branch off Platinum Premier Projects who deal in all types of construction projects. Platinum Electrics are based in London...
From £17,612
JJSR Construction Ltd is an established and experienced local extension builder in Welwyn. Please contact us for a free, no obligation quote and co...

Underpinning ranges from £17,420 (Nisup Building Services based in HA8) to £19,084 (Propello based in E17), 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 Welwyn by posting a job with HaMuch and we will send it to extension builders in Welwyn.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Welwyn Garden City | £42 | £268 |
| Underpin A Building near Hertford | £46 | £289 |
| Underpin A Building near Hatfield | £64 | £283 |
| Underpin A Building near Stevenage | £44 | £282 |
| Underpin A Building near Harpenden | £86 | £315 |
| Underpin A Building near Hitchin | £43 | £283 |
| Underpin A Building near East Hertfordshire | £44 | £289 |
| Underpin A Building near Ware | £47 | £296 |
| Underpin A Building near St Albans | £63 | £288 |
| Underpin A Building near North Hertfordshire | £44 | £283 |
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 - £17,930

Two storey extension - £88,646

Build a timber frame extension - £26,430

Build a swimming pool - £81,430

Single storey extension - £63,608

Side return extension - £46,342

Install an RSJ - £2,630

Outbuilding - £10,430

Build a Mansard loft conversion - £52,430

Loft conversion - £37,785

Build a kitchen extension - £42,430

Hip to gable loft conversion - £42,430

Granny annexe - £87,430

Garden office - £10,430

Convert a Garage - £16,430

Garage - £18,930

Build a flat roof extension - £22,430

Build a dormer loft conversion - £42,430

Concrete foundations - £6,680

Convert a bungalow loft - £29,430

Convert a basement - £42,342