From £2,328
Fornia Build Ltd is an established and experienced local extension builder in EC1Y. Please contact us for a free, no obligation quote and competiti...
From £2,728
Bring your vision to life with Fornia build. Our main aim is to design and build exceptional residential properties in prime locations, to the high...
From £2,240
TOP CONSTRUCTION is an established extension buildering business in EC1Y. We come highly recommended and provide competitive quotes for your work.<...
From £2,360
Venta Construction is an established and experienced local extension builder in EC1Y. Please contact us for a free, no obligation quote and competi...
From £2,472
Need an Extension Builder in EC1Y? Aylaa Exclusive has been helping local clients (5 mile radius) with their extension buildering jobs for many yea...
From £2,296
Our family-run building services company Dual City Building Contractors Limited has over 30 years’ experience in the industry. We have been helpi...
From £2,568
Need to find an Extension Builder near you for all your extension buildering work?
Alkemist Build and Decorate provides a local, trusted ex...
From £2,600
Need an Extension Builder in EC1Y? Cadway Group Ltd has been helping local clients (5 mile radius) with their extension buildering jobs for many ye...
From £2,328
Master Build Team is an established extension buildering business in EC1Y. We come highly recommended and provide competitive quotes for your work....
From £2,160
Relax... you have found a reliable extension builder in EC1Y. MM Construction Group is a friendly and reliable company based in EC1Y who consider n...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in EC1Y it ranges from £2,160 (MM Construction Group based in EC1V) to £2,728 (Fornia Build Ltd based in EC1V).
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 EC1Y by posting a job with HaMuch and we will send it to extension builders in EC1Y.
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 - £17,708

Two storey extension - £88,312

Build a timber frame extension - £26,208

Build a swimming pool - £81,208

Single storey extension - £59,160

Side return extension - £43,840

Install an RSJ - £2,408

Outbuilding - £10,208

Build a Mansard loft conversion - £52,208

Loft conversion - £35,700

Build a kitchen extension - £42,208

Hip to gable loft conversion - £42,208

Granny annexe - £87,208

Garden office - £10,208

Convert a Garage - £16,208

Garage - £18,708

Build a flat roof extension - £22,208

Build a dormer loft conversion - £42,208

Concrete foundations - £6,458

Convert a bungalow loft - £29,208

Convert a basement - £39,840