From £2,344
We are a small family run business with over 20 years experience in brickwork, bathroom/kitchen fitting, roofing, landscaping, fencing, tiling and ...
From £2,216
Trusted and professional extension builder in SO40. Experienced in all extension buildering work and keeping within budget and on quote. GMS Carpen...
From £2,424
Elmer Building Services ltd is an established extension buildering business in SO40. We come highly recommended and provide competitive quotes for ...
From £2,344
Bailey Construction Services are here to help customers who need an Extension Builder in SO40. We offer a competitive rate to complete all your ext...
From £3,400
Building extensions and conversions - commercial and domesticstructural repairsgroundworksdrainage workspaving, patios and concreti...
From £1,952
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,320
Need to find an Extension Builder near you for all your extension buildering work?
Mobile Services provides a local, trusted extension buil...
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 £2,336
Claytons Building and Roofing are here to help customers who need an Extension Builder in SO40. We offer a competitive rate to complete all your ex...
From £2,160
ROB DINE CONSTRUCTION is an established and experienced local extension builder in SO40. Please contact us for a free, no obligation quote and comp...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in SO40 it ranges from £1,952 (Steve Lovett Builders based in SO18) to £3,400 (Wade and Son Builders based in bh22).
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 SO40 by posting a job with HaMuch and we will send it to extension builders in SO40.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Totton | £34 | £243 |
| Install An RSJ near Southampton | £34 | £243 |
| Install An RSJ near Romsey | £32 | £230 |
| Install An RSJ near New Forest | £32 | £245 |
| Install An RSJ near Eastleigh | £34 | £244 |
| Install An RSJ near Chandler's Ford | £34 | £245 |
| Install An RSJ near Hedge End | £34 | £244 |
| Install An RSJ near Locks Heath | £33 | £240 |
| Install An RSJ near Winchester | £37 | £266 |
| Install An RSJ near Fareham | £35 | £250 |
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 - £17,689

Two storey extension - £88,283

Build a timber frame extension - £26,189

Build a swimming pool - £81,189

Single storey extension - £58,776

Side return extension - £43,624

Install an RSJ - £2,389

Outbuilding - £10,189

Build a Mansard loft conversion - £52,189

Loft conversion - £35,520

Build a kitchen extension - £42,189

Hip to gable loft conversion - £42,189

Granny annexe - £87,189

Garden office - £10,189

Convert a Garage - £16,189

Garage - £18,689

Build a flat roof extension - £22,189

Build a dormer loft conversion - £42,189

Concrete foundations - £6,439

Convert a bungalow loft - £29,189

Convert a basement - £39,624