From £2,248
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in DA15. No obligation free quotes...
From £2,392
Gb construction are here to help customers who need an Extension Builder in DA15. We offer a competitive rate to complete all your extension build...
From £2,384
Experienced extension builder ready to quote for your work. CC&D BUILDING LTD is the best extension builder in DA15. No obligation free quotes and ...
From £2,760
Our homes need to be regularly maintained and from time to time they need to be rejuvenated, modernised and enhanced. When it comes to building wor...
From £2,296
Experienced extension builder ready to quote for your work. Mr is the best extension builder in DA15. No obligation free quotes and many happy cust...
From £2,184
JK Doors is a trusted extension builder serving customers in DA15 and the surrounding area. Contact us to today to get a competitive quote for exte...
From £2,392
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...
From £2,592
Need an Extension Builder in DA15? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many ye...
From £2,512
skilled worker who specializes in completing a wide range of building and renovation projects
From £2,816
HOUSE BUILDING SERVICES LIMITED is a trusted extension builder serving customers in DA15 and the surrounding area. Contact us to today to get a com...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in DA15 it ranges from £2,184 (JK Doors based in W1W) to £2,816 (HOUSE BUILDING SERVICES LIMITED based in DA16).
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 DA15 by posting a job with HaMuch and we will send it to extension builders in DA15.
"RSJ installation - check if we need one installed" - ELTHAM, job posted 01/06/25
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 - £17,758

Two storey extension - £88,386

Build a timber frame extension - £26,258

Build a swimming pool - £81,258

Single storey extension - £60,152

Side return extension - £44,398

Install an RSJ - £2,458

Outbuilding - £10,258

Build a Mansard loft conversion - £52,258

Loft conversion - £36,165

Build a kitchen extension - £42,258

Hip to gable loft conversion - £42,258

Granny annexe - £87,258

Garden office - £10,258

Convert a Garage - £16,258

Garage - £18,758

Build a flat roof extension - £22,258

Build a dormer loft conversion - £42,258

Concrete foundations - £6,508

Convert a bungalow loft - £29,258

Convert a basement - £40,398