From £2,440
JAS Housing Developments is an established and experienced local extension builder in AL1. Please contact us for a free, no obligation quote and co...
From £2,480
Need to find an Extension Builder near you for all your extension buildering work?
JGS Building Ltd provides a local, trusted extension bui...
From £2,440
Beswick Building and Renovations LTD is a trusted extension builder serving customers in AL1 and the surrounding area. Contact us to today to get a...
From £2,336
Relax... you have found a reliable extension builder in AL1. Property Interior Services is a friendly and reliable company based in AL1 who conside...
From £2,520
Relax... you have found a reliable extension builder in AL1. Designer Shade Solutions is a friendly and reliable company based in AL1 who consider ...
From £2,640
IC Builders have been helping customers in St Albans and the surrounding area by providing professional, trustworthy building services.We k...
From £2,280
Trusted and professional extension builder in AL1. Experienced in all extension buildering work and keeping within budget and on quote. P & A Doher...
From £2,344
Relax... you have found a reliable extension builder in AL1. DK Home Refurbishment Limited is a friendly and reliable company based in AL1 who cons...
From £2,416
Ebro Construction Group are here to help customers who need an Extension Builder in AL1. We offer a competitive rate to complete all your extension...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in AL1 it ranges from £2,224 (Planson’s Building Services based in AL1) to £2,640 (IC Builders based in AL1).
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 AL1 by posting a job with HaMuch and we will send it to extension builders in AL1.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near St Albans | £63 | £288 |
| Install An RSJ near Hatfield | £64 | £283 |
| Install An RSJ near Harpenden | £86 | £315 |
| Install An RSJ near Borehamwood | £42 | £270 |
| Install An RSJ near Welwyn Garden City | £42 | £268 |
| Install An RSJ near Hemel Hempstead | £42 | £270 |
| Install An RSJ near Potters Bar | £43 | £273 |
| Install An RSJ near Bushey | £42 | £276 |
| Install An RSJ near Dacorum | £42 | £269 |
| Install An RSJ near Watford | £43 | £278 |
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 - £17,712

Two storey extension - £88,318

Build a timber frame extension - £26,212

Build a swimming pool - £81,212

Single storey extension - £59,240

Side return extension - £43,885

Install an RSJ - £2,412

Outbuilding - £10,212

Build a Mansard loft conversion - £52,212

Loft conversion - £35,738

Build a kitchen extension - £42,212

Hip to gable loft conversion - £42,212

Granny annexe - £87,212

Garden office - £10,212

Convert a Garage - £16,212

Garage - £18,712

Build a flat roof extension - £22,212

Build a dormer loft conversion - £42,212

Concrete foundations - £6,462

Convert a bungalow loft - £29,212

Convert a basement - £39,885