From £2,576
CK Constructions & Development Ltd is a trusted extension builder serving customers in WC1B and the surrounding area. Contact us to today to get a ...
From £2,600
FLAVIA CONDE is an established and experienced local extension builder in WC1B. Please contact us for a free, no obligation quote and competitive r...
From £2,384
Need to find an Extension Builder near you for all your extension buildering work?
Pacho Build Ltd provides a local, trusted extension buil...
From £2,672
Longland Construction LTD is a high end refurbishment contractor and sub contractor company in London and surrounding areas. Woodwork, painting and...
From £2,344
House Rendering Ltd is a trusted extension builder serving customers in WC1B and the surrounding area. Contact us to today to get a competitive quo...
From £2,440
Relax... you have found a reliable extension builder in WC1B. HouseUP is a friendly and reliable company based in WC1B who consider no job as too b...
From £2,400
Experienced extension builder ready to quote for your work. My Trusted Builder is the best extension builder in WC1B. No obligation free quotes and...
From £2,224
Need to find an Extension Builder near you for all your extension buildering work?
ORO Projects provides a local, trusted extension builder...
From £2,472
Trusted and professional extension builder in WC1B. Experienced in all extension buildering work and keeping within budget and on quote. ElleHaus h...
From £2,280
Whitehorse Build London offers a full management service running each project from design through to completion, removing many of the hassle associ...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in WC1B it ranges from £2,224 (ORO Projects based in WC2H) to £2,672 (Longland Construction based in WC1N).
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 WC1B by posting a job with HaMuch and we will send it to extension builders in WC1B.
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 - £17,739

Two storey extension - £88,359

Build a timber frame extension - £26,239

Build a swimming pool - £81,239

Single storey extension - £59,784

Side return extension - £44,191

Install an RSJ - £2,439

Outbuilding - £10,239

Build a Mansard loft conversion - £52,239

Loft conversion - £35,993

Build a kitchen extension - £42,239

Hip to gable loft conversion - £42,239

Granny annexe - £87,239

Garden office - £10,239

Convert a Garage - £16,239

Garage - £18,739

Build a flat roof extension - £22,239

Build a dormer loft conversion - £42,239

Concrete foundations - £6,489

Convert a bungalow loft - £29,239

Convert a basement - £40,191