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 £1,952
Need an Extension Builder in L3? ARGYLE BUILDING AND MAINTENANCE has been helping local clients (20 mile radius) with their extension buildering jo...
From £1,992
J J Nuttall Specialist Roofing Ltd are here to help customers who need an Extension Builder in L3. We offer a competitive rate to complete all your...
From £2,216
Art Henry's are here to help customers who need an Extension Builder in L3. We offer a competitive rate to complete all your extension buildering j...
From £1,872
J.M.C Building Services is a trusted extension builder serving customers in L3 and the surrounding area. Contact us to today to get a competitive q...
From £2,000
Experienced extension builder ready to quote for your work. Oxygen Property Partners is the best extension builder in L3. No obligation free quote...
From £2,104
Glassrooms is an established extension buildering business in L3. We come highly recommended and provide competitive quotes for your work.
From £1,864
Accro Building Services is an established extension buildering business in L3. We come highly recommended and provide competitive quotes for your w...
From £2,072
Relax... you have found a reliable extension builder in L3. Britannia Builders is a friendly and reliable company based in L3 who consider no job a...
From £1,936
Trusted and professional extension builder in L3. 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 L3 it ranges from £1,864 (Accro Building Services based in CH44) 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 L3 by posting a job with HaMuch and we will send it to extension builders in L3.
"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 Wirral | £31 | £219 |
| Install An RSJ near Bebington | £31 | £222 |
| 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 - £17,318

Two storey extension - £87,726

Build a timber frame extension - £25,818

Build a swimming pool - £80,818

Single storey extension - £51,352

Side return extension - £39,448

Install an RSJ - £2,018

Outbuilding - £9,818

Build a Mansard loft conversion - £51,818

Loft conversion - £32,040

Build a kitchen extension - £41,818

Hip to gable loft conversion - £41,818

Granny annexe - £86,818

Garden office - £9,818

Convert a Garage - £15,818

Garage - £18,318

Build a flat roof extension - £21,818

Build a dormer loft conversion - £41,818

Concrete foundations - £6,068

Convert a bungalow loft - £28,818

Convert a basement - £35,448