From £16,676
Trusted and professional extension builder in BT12. Experienced in all extension buildering work and keeping within budget and on quote. Extended l...
From £16,868
Relax... you have found a reliable extension builder in BT12. SM Plumbing & Heating is a friendly and reliable company based in BT12 who consider n...
From £16,836
Trusted and professional extension builder in BT12. Experienced in all extension buildering work and keeping within budget and on quote. Belfast Lo...
From £16,884
Designco Ltd is an established extension buildering business in BT12. We come highly recommended and provide competitive quotes for your work.
...From £16,876
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £16,796
Ballantine building solutions is an established extension buildering business in BT12. We come highly recommended and provide competitive quotes fo...
From £16,636
Need to find an Extension Builder near you for all your extension buildering work?
Mount Oriel Conversions & Extensions provides a local, t...
From £16,884
Relax... you have found a reliable extension builder in BT12. Finch Construction NI is a friendly and reliable company based in BT12 who consider n...
From £16,900
T.I Building is a trusted extension builder serving customers in BT12 and the surrounding area. Contact us to today to get a competitive quote for ...

Underpinning ranges from £16,636 (Mount Oriel Conversions & Extensions based in BT8) to £16,988 (AK Building Services based in BT8), 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 BT12 by posting a job with HaMuch and we will send it to extension builders in BT12.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Belfast | £23 | £161 |
| Underpin A Building near Carryduff | £23 | £158 |
| Underpin A Building near Holywood | £23 | £159 |
| Underpin A Building near Lisburn | £24 | £164 |
| Underpin A Building near Greenisland | £23 | £153 |
| Underpin A Building near Comber | £22 | £160 |
| Underpin A Building near Hillsborough and Culcavy | £25 | £170 |
| Underpin A Building near Crumlin | £26 | £194 |
| Underpin A Building near Ballygowan | £24 | £183 |
| Underpin A Building near Saintfield | £23 | £162 |
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 - £16,834

Two storey extension - £87,002

Build a timber frame extension - £25,334

Build a swimming pool - £80,334

Single storey extension - £41,688

Side return extension - £34,012

Install an RSJ - £1,534

Outbuilding - £9,334

Build a Mansard loft conversion - £51,334

Loft conversion - £27,510

Build a kitchen extension - £41,334

Hip to gable loft conversion - £41,334

Granny annexe - £86,334

Garden office - £9,334

Convert a Garage - £15,334

Garage - £17,834

Build a flat roof extension - £21,334

Build a dormer loft conversion - £41,334

Concrete foundations - £5,584

Convert a bungalow loft - £28,334

Convert a basement - £30,012