From £16,796
Been in business as 18 years alway put clients first and never had any combacks
From £16,876
Antrim, BT36
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £16,932
We have over 25 years experience in all building work and renowned for good workmanship All jobs small and large taken on
From £16,884
Antrim, BT36
Designco Ltd is an established extension buildering business in Antrim. We come highly recommended and provide competitive quotes for your work.
From £16,836
Trusted and professional extension builder in Antrim. Experienced in all extension buildering work and keeping within budget and on quote. Belfast ...
From £16,764
Antrim, BT37
Trusted and professional extension builder in Antrim. Experienced in all extension buildering work and keeping within budget and on quote. DGA have...
From £16,796
Antrim, BT37
Ballantine building solutions is an established extension buildering business in Antrim. We come highly recommended and provide competitive quotes ...
From £16,676
Trusted and professional extension builder in Antrim. Experienced in all extension buildering work and keeping within budget and on quote. Extended...
From £16,884
Antrim, BT28
Relax... you have found a reliable extension builder in Antrim. Finch Construction NI is a friendly and reliable company based in Antrim who consid...

Underpinning ranges from £16,676 (Extended living by Gilbert-Ash based in BT12) to £18,060 (Build a Boiler based in BT67), 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 Antrim by posting a job with HaMuch and we will send it to extension builders in Antrim.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Crumlin | £26 | £194 |
| Underpin A Building near Ballyclare | £20 | £124 |
| Underpin A Building near Magherafelt | £30 | £238 |
| Underpin A Building near Maghaberry | £31 | £205 |
| Underpin A Building near Greenisland | £23 | £153 |
| Underpin A Building near Belfast | £23 | £161 |
| Underpin A Building near Lisburn | £24 | £164 |
| Underpin A Building near Carrickfergus | £23 | £158 |
| Underpin A Building near Holywood | £23 | £159 |
| Underpin A Building near Hillsborough and Culcavy | £25 | £170 |
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 - £16,950

Two storey extension - £87,176

Build a timber frame extension - £25,450

Build a swimming pool - £80,450

Single storey extension - £44,008

Side return extension - £35,317

Install an RSJ - £1,650

Outbuilding - £9,450

Build a Mansard loft conversion - £51,450

Loft conversion - £28,598

Build a kitchen extension - £41,450

Hip to gable loft conversion - £41,450

Granny annexe - £86,450

Garden office - £9,450

Convert a Garage - £15,450

Garage - £17,950

Build a flat roof extension - £21,450

Build a dormer loft conversion - £41,450

Concrete foundations - £5,700

Convert a bungalow loft - £28,450

Convert a basement - £31,317