From £16,868
Relax... you have found a reliable extension builder in Down. SM Plumbing & Heating is a friendly and reliable company based in Down who consider n...
From £16,884
Designco Ltd is an established extension buildering business in Down. We come highly recommended and provide competitive quotes for your work.
...From £16,676
Trusted and professional extension builder in Down. Experienced in all extension buildering work and keeping within budget and on quote. Extended l...
From £16,796
Ballantine building solutions is an established extension buildering business in Down. 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 £16,764
Trusted and professional extension builder in Down. Experienced in all extension buildering work and keeping within budget and on quote. DGA have m...
From £16,772
Down, BT30
apex pharaoh ltd is a trusted extension builder serving customers in Down and the surrounding area. Contact us to today to get a competitive quote ...
From £16,836
Trusted and professional extension builder in Down. Experienced in all extension buildering work and keeping within budget and on quote. Belfast Lo...
From £16,876
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

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 Down by posting a job with HaMuch and we will send it to extension builders in Down.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Comber | £22 | £160 |
| Underpin A Building near Holywood | £23 | £159 |
| Underpin A Building near Ballygowan | £24 | £183 |
| Underpin A Building near Belfast | £23 | £161 |
| Underpin A Building near Carryduff | £23 | £158 |
| Underpin A Building near Bangor | £24 | £183 |
| Underpin A Building near Bangor | £24 | £183 |
| Underpin A Building near Greenisland | £23 | £153 |
| Underpin A Building near Saintfield | £23 | £162 |
| Underpin A Building near Carrickfergus | £23 | £158 |
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 - £16,810

Two storey extension - £86,964

Build a timber frame extension - £25,310

Build a swimming pool - £80,310

Single storey extension - £41,192

Side return extension - £33,733

Install an RSJ - £1,510

Outbuilding - £9,310

Build a Mansard loft conversion - £51,310

Loft conversion - £27,278

Build a kitchen extension - £41,310

Hip to gable loft conversion - £41,310

Granny annexe - £86,310

Garden office - £9,310

Convert a Garage - £15,310

Garage - £17,810

Build a flat roof extension - £21,310

Build a dormer loft conversion - £41,310

Concrete foundations - £5,560

Convert a bungalow loft - £28,310

Convert a basement - £29,733