Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
Experienced extension builder ready to quote for your work. A South View is the best extension builder in Colnbrook. No obligation free quotes and ...
Colnbrook, SL3
MRE Maintenance Services is an established and experienced local extension builder in Colnbrook. Please contact us for a free, no obligation quote ...
BeautifulRenovation are here to help customers who need an Extension Builder in Colnbrook. We offer a competitive rate to complete all your extensi...
Experienced extension builder ready to quote for your work. Sherry Construction is the best extension builder in Colnbrook. No obligation free quot...
EIC Builders Ltd are here to help customers who need an Extension Builder in Colnbrook. We offer a competitive rate to complete all your extension ...
Colnbrook, SL3
BDR Home Improvement are here to help customers who need an Extension Builder in Colnbrook. We offer a competitive rate to complete all your extens...
Dub Solutions is a trusted extension builder serving customers in Colnbrook and the surrounding area. Contact us to today to get a competitive quot...
Lee Townsend
Need to find an Extension Builder near you for all your extension buildering work?
Lp Townsend Brickwork provides a local, trusted extensio...
B.A Ruffle Building Contractor is an established extension buildering business in Colnbrook. We come highly recommended and provide competitive quo...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Colnbrook it ranges from £1,880 (Lp Townsend Brickwork based in SL2) to £2,512 (T M Builder based in UB4).
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 Colnbrook by posting a job with HaMuch and we will send it to extension builders in Colnbrook.
"RSJ installation" - SLOUGH, job posted 05/07/25
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Slough | £42 | £272 |
| Install An RSJ near Windsor & Maidenhead | £42 | £272 |
| Install An RSJ near Windsor | £41 | £271 |
| Install An RSJ near Staines-upon-Thames | £42 | £269 |
| Install An RSJ near Egham | £42 | £266 |
| Install An RSJ near Hillingdon | £63 | £276 |
| Install An RSJ near Gerrards Cross | £43 | £282 |
| Install An RSJ near Maidenhead | £41 | £273 |
| Install An RSJ near Ascot | £41 | £276 |
| Install An RSJ near Sunbury-on-Thames | £42 | £279 |
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 - £17,554

Two storey extension - £88,080

Build a timber frame extension - £26,054

Build a swimming pool - £81,054

Single storey extension - £56,072

Side return extension - £42,103

Install an RSJ - £2,254

Outbuilding - £10,054

Build a Mansard loft conversion - £52,054

Loft conversion - £34,253

Build a kitchen extension - £42,054

Hip to gable loft conversion - £42,054

Granny annexe - £87,054

Garden office - £10,054

Convert a Garage - £16,054

Garage - £18,554

Build a flat roof extension - £22,054

Build a dormer loft conversion - £42,054

Concrete foundations - £6,304

Convert a bungalow loft - £29,054

Convert a basement - £38,103