From £1,776
CAMWOOD BUILDING SERVICES is an established extension buildering business in CF5. We come highly recommended and provide competitive quotes for you...
From £1,960
RDL BUILDING SERVICES LTD is a trusted extension builder serving customers in CF5 and the surrounding area. Contact us to today to get a competitiv...
From £2,008
CJ BUILDING SERVICES are here to help customers who need an Extension Builder in CF5. We offer a competitive rate to complete all your extension bu...
From £2,008
Experienced extension builder ready to quote for your work. Chapman Builders is the best extension builder in CF5. No obligation free quotes and ma...
From £1,960
Construction Jobs is an established and experienced local extension builder in CF5. Please contact us for a free, no obligation quote and competiti...
From £1,760
Member since June 2026
Trusted and professional extension builder in CF5. Experienced in all extension buildering work and keeping within budget and on quote. Elite Build...
From £1,800
MARWAY BUILDING LTD is a trusted extension builder serving customers in CF5 and the surrounding area. Contact us to today to get a competitive quot...
From £2,072
GRE BUILDING SERVICES is an established and experienced local extension builder in CF5. Please contact us for a free, no obligation quote and compe...
From £1,928
The Philog Paving Services is an established extension buildering business in CF5. We come highly recommended and provide competitive quotes for yo...
From £1,920
Vencer understand that when it comes to delivering client\nsatisfaction, the project or property involved will require\nbeing delivered on time, wi...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in CF5 it ranges from £1,760 (Elite Building Contractors South Wales based in Cf5) to £2,072 (GRE BUILDING SERVICES based in CF5).
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 CF5 by posting a job with HaMuch and we will send it to extension builders in CF5.
"RSJ installation to open up kitchen and utility room. About 2m wide." - CARDIFF, job posted 01/01/70
"RSJ installation" - CARDIFF, job posted 01/01/70
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Cardiff | £35 | £219 |
| Install An RSJ near Penarth | £36 | £217 |
| Install An RSJ near Barry | £33 | £218 |
| Install An RSJ near Church Village | £34 | £214 |
| Install An RSJ near Caerphilly | £33 | £208 |
| Install An RSJ near Pontypridd | £33 | £211 |
| Install An RSJ near Risca | £32 | £218 |
| Install An RSJ near Vale of Glamorgan | £29 | £217 |
| Install An RSJ near Rhondda | £31 | £206 |
| Install An RSJ near Newport | £41 | £233 |
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 - £17,219

Two storey extension - £87,579

Build a timber frame extension - £25,719

Build a swimming pool - £80,719

Single storey extension - £49,384

Side return extension - £38,341

Install an RSJ - £1,919

Outbuilding - £9,719

Build a Mansard loft conversion - £51,719

Loft conversion - £31,118

Build a kitchen extension - £41,719

Hip to gable loft conversion - £41,719

Granny annexe - £86,719

Garden office - £9,719

Convert a Garage - £15,719

Garage - £18,219

Build a flat roof extension - £21,719

Build a dormer loft conversion - £41,719

Concrete foundations - £5,969

Convert a bungalow loft - £28,719

Convert a basement - £34,341