Experienced extension builder ready to quote for your work. Grant Construction is the best extension builder in SO51. No obligation free quotes and...
The business offers a full design service for both kitchens and bathrooms.We work with you to make the best use of your space and find prod...
From £1,488
James Golby
All our work carries a life time guarantee , If we did it and you have a problem we want to know about it. Not the bloke in the pub or your next do...
From £2,472
Ibcon Construction is an established and experienced local extension builder in SO51. Please contact us for a free, no obligation quote and competi...
From £2,112
BUY BUILDER LTD is an established extension buildering business in SO51. We come highly recommended and provide competitive quotes for your work.
From £2,160
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,104
Our building services company KT Carpentry & Building Services has been helping customers in Southampton, Winchester, Brockenhurst and Portsmouth b...
From £2,264
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in SO51 it ranges from £1,488 (James Golby Construction based in SO51) to £2,472 (Ibcon Construction based in SO51).
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 SO51 by posting a job with HaMuch and we will send it to extension builders in SO51.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Romsey | £32 | £230 |
| Install An RSJ near Chandler's Ford | £34 | £245 |
| Install An RSJ near Totton | £34 | £243 |
| Install An RSJ near Eastleigh | £34 | £244 |
| Install An RSJ near Southampton | £34 | £243 |
| Install An RSJ near Test Valley | £37 | £261 |
| Install An RSJ near New Forest | £32 | £245 |
| Install An RSJ near Winchester | £39 | £283 |
| Install An RSJ near Hedge End | £34 | £244 |
| Install An RSJ near Locks Heath | £33 | £240 |
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 - £17,453

Two storey extension - £87,930

Build a timber frame extension - £25,953

Build a swimming pool - £80,953

Single storey extension - £54,060

Side return extension - £40,971

Install an RSJ - £2,153

Outbuilding - £9,953

Build a Mansard loft conversion - £51,953

Loft conversion - £33,309

Build a kitchen extension - £41,953

Hip to gable loft conversion - £41,953

Granny annexe - £86,953

Garden office - £9,953

Convert a Garage - £15,953

Garage - £18,453

Build a flat roof extension - £21,953

Build a dormer loft conversion - £41,953

Concrete foundations - £6,203

Convert a bungalow loft - £28,953

Convert a basement - £36,971