From £2,160
Experienced extension builder ready to quote for your work. LMR BUILDING SERVICES LIMITED is the best extension builder in SO15. No obligation free...
From £2,344
Bailey Construction Services are here to help customers who need an Extension Builder in SO15. We offer a competitive rate to complete all your ext...
From £2,280
Experienced extension builder ready to quote for your work. Shay building LTD is the best extension builder in SO15. No obligation free quotes and ...
From £2,120
Need to find an Extension Builder near you for all your extension buildering work?
DSH Roofing provides a local, trusted extension builderi...
From £2,128
Loki Projects & Development specialises in design, construction & project management.
From £1,928
Hestia Trustins LTD are here to help customers who need an Extension Builder in SO15. We offer a competitive rate to complete all your extension bu...
From £2,392
We are a Design and Build company based in Hampshire. Proud of our roots, we try to be the very best in the way we go about our business. Friendly...
From £2,168
Trusted and professional extension builder in SO15. Experienced in all extension buildering work and keeping within budget and on quote. LG PLANNIN...
From £2,128
Relax... you have found a reliable extension builder in SO15. 1st Oak Building Preservation & Maintenance is a friendly and reliable company based ...
From £1,968
Need to find an Extension Builder near you for all your extension buildering work?
Mark Mckie provides a local, trusted extension builderin...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in SO15 it ranges from £1,928 (Hestia Trustins LTD based in SO14) to £2,392 (AAConcepts based in SO14).
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 SO15 by posting a job with HaMuch and we will send it to extension builders in SO15.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Southampton | £30 | £215 |
| Install An RSJ near Totton | £30 | £216 |
| Install An RSJ near Eastleigh | £30 | £215 |
| Install An RSJ near Chandler's Ford | £30 | £216 |
| Install An RSJ near Hedge End | £30 | £215 |
| Install An RSJ near Romsey | £28 | £203 |
| Install An RSJ near Locks Heath | £30 | £213 |
| Install An RSJ near New Forest | £28 | £211 |
| Install An RSJ near Fareham | £31 | £217 |
| Install An RSJ near Winchester | £31 | £225 |
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 - £17,462

Two storey extension - £87,942

Build a timber frame extension - £25,962

Build a swimming pool - £80,962

Single storey extension - £54,232

Side return extension - £41,068

Install an RSJ - £2,162

Outbuilding - £9,962

Build a Mansard loft conversion - £51,962

Loft conversion - £33,390

Build a kitchen extension - £41,962

Hip to gable loft conversion - £41,962

Granny annexe - £86,962

Garden office - £9,962

Convert a Garage - £15,962

Garage - £18,462

Build a flat roof extension - £21,962

Build a dormer loft conversion - £41,962

Concrete foundations - £6,212

Convert a bungalow loft - £28,962

Convert a basement - £37,068