From £1,600
T.I Building is a trusted extension builder serving customers in Hillsborough and the surrounding area. Contact us to today to get a competitive qu...
From £1,584
Relax... you have found a reliable extension builder in Hillsborough. Finch Construction NI is a friendly and reliable company based in Hillsboroug...
From £1,336
Need to find an Extension Builder near you for all your extension buildering work?
Mount Oriel Conversions & Extensions provides a local, t...
From £1,536
Trusted and professional extension builder in Hillsborough. Experienced in all extension buildering work and keeping within budget and on quote. Be...
From £1,376
Trusted and professional extension builder in Hillsborough. Experienced in all extension buildering work and keeping within budget and on quote. Ex...
From £1,712
N W Doyle & Son is a trusted extension builder serving customers in Hillsborough and the surrounding area. Contact us to today to get a competitive...
From £1,648
Trusted and professional extension builder in Hillsborough. Experienced in all extension buildering work and keeping within budget and on quote. Th...
From £1,568
Relax... you have found a reliable extension builder in Hillsborough. SM Plumbing & Heating is a friendly and reliable company based in Hillsboroug...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Hillsborough it ranges from £1,336 (Mount Oriel Conversions & Extensions based in BT8) to £2,760 (Build a Boiler based in BT67).
Comparing extension builders estimates for fitting an RSJ gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
Get rates and quotes to install an RSJ in Hillsborough by posting a job with HaMuch and we will send it to extension builders in Hillsborough.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Hillsborough and Culcavy | £25 | £170 |
| Install An RSJ near Lisburn | £24 | £164 |
| Install An RSJ near Maghaberry | £31 | £205 |
| Install An RSJ near Ballynahinch | £19 | £189 |
| Install An RSJ near Carryduff | £23 | £158 |
| Install An RSJ near Saintfield | £23 | £162 |
| Install An RSJ near Waringstown | £23 | £167 |
| Install An RSJ near Banbridge | £29 | £205 |
| Install An RSJ near Belfast | £23 | £161 |
| Install An RSJ near Crumlin | £26 | £194 |
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 - £16,981

Two storey extension - £87,221

Build a timber frame extension - £25,481

Build a swimming pool - £80,481

Single storey extension - £44,616

Side return extension - £35,659

Install an RSJ - £1,681

Outbuilding - £9,481

Build a Mansard loft conversion - £51,481

Loft conversion - £28,883

Build a kitchen extension - £41,481

Hip to gable loft conversion - £41,481

Granny annexe - £86,481

Garden office - £9,481

Convert a Garage - £15,481

Garage - £17,981

Build a flat roof extension - £21,481

Build a dormer loft conversion - £41,481

Concrete foundations - £5,731

Convert a bungalow loft - £28,481

Convert a basement - £31,659