From £1,952
Need an Extension Builder in L1? ARGYLE BUILDING AND MAINTENANCE has been helping local clients (20 mile radius) with their extension buildering jo...
From £2,168
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,216
Art Henry's are here to help customers who need an Extension Builder in L1. We offer a competitive rate to complete all your extension buildering j...
From £1,992
J J Nuttall Specialist Roofing Ltd are here to help customers who need an Extension Builder in L1. We offer a competitive rate to complete all your...
From £2,000
Experienced extension builder ready to quote for your work. Oxygen Property Partners is the best extension builder in L1. No obligation free quote...
From £1,872
J.M.C Building Services is a trusted extension builder serving customers in L1 and the surrounding area. Contact us to today to get a competitive q...
From £2,016
DK Building is an established extension buildering business in L1. We come highly recommended and provide competitive quotes for your work.
From £2,104
Glassrooms is an established extension buildering business in L1. We come highly recommended and provide competitive quotes for your work.
From £2,072
Relax... you have found a reliable extension builder in L1. Britannia Builders is a friendly and reliable company based in L1 who consider no job a...
From £1,936
Trusted and professional extension builder in L1. Experienced in all extension buildering work and keeping within budget and on quote. MA Roofing &...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in L1 it ranges from £1,872 (J.M.C Building Services based in L4) to £2,216 (Art Henry's based in L8).
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 L1 by posting a job with HaMuch and we will send it to extension builders in L1.
"RSJ installation" - LIVERPOOL, job posted 04/09/25
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Liverpool | £31 | £222 |
| Install An RSJ near Birkenhead | £31 | £219 |
| Install An RSJ near Wallasey | £33 | £224 |
| Install An RSJ near Bootle | £32 | £223 |
| Install An RSJ near Bebington | £31 | £222 |
| Install An RSJ near Wirral | £31 | £219 |
| Install An RSJ near Crosby | £34 | £223 |
| Install An RSJ near Kirkby | £31 | £222 |
| Install An RSJ near Huyton with Roby | £31 | £225 |
| Install An RSJ near Knowsley | £31 | £221 |
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 - £17,333

Two storey extension - £87,749

Build a timber frame extension - £25,833

Build a swimming pool - £80,833

Single storey extension - £51,656

Side return extension - £39,619

Install an RSJ - £2,033

Outbuilding - £9,833

Build a Mansard loft conversion - £51,833

Loft conversion - £32,183

Build a kitchen extension - £41,833

Hip to gable loft conversion - £41,833

Granny annexe - £86,833

Garden office - £9,833

Convert a Garage - £15,833

Garage - £18,333

Build a flat roof extension - £21,833

Build a dormer loft conversion - £41,833

Concrete foundations - £6,083

Convert a bungalow loft - £28,833

Convert a basement - £35,619