From £2,280
Greater London, SW3
ADOVA are here to help customers who need an Extension Builder in SW3. We offer a competitive rate to complete all your extension buildering jobs t...
From £2,464
Trusted and professional extension builder in SW3. Experienced in all extension buildering work and keeping within budget and on quote. Oro Project...
From £2,448
Greater London, SW3
Experienced extension builder ready to quote for your work. Clarisford is the best extension builder in SW3. No obligation free quotes and many hap...
From £2,728
Clarisford is a property developer and Design & Build firm that specialise in the creation of extraordinary projects from concept all the way to co...
From £2,608
Our building services company Autas Developments have fifteen years' experience of helping customers in Central London and the surrounding areas by...
From £2,464
We specialise in mid to high end residential renovations.Offering comprehensive Design and Build packages that Inc all necessary reports, plans and...
From £2,096
Trusted and professional extension builder in SW3. Experienced in all extension buildering work and keeping within budget and on quote. Sloane Ave ...
From £2,592
Trusted and professional extension builder in SW3. Experienced in all extension buildering work and keeping within budget and on quote. Property Re...
From £2,624
Greater London, SW3
Builders by Design Ltd are here to help customers who need an Extension Builder in SW3. We offer a competitive rate to complete all your extension ...
From £2,536
Need to find an Extension Builder near you for all your extension buildering work?
Hearne House provides a local, trusted extension builder...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in SW3 it ranges from £2,096 (Sloane Ave Renovations based in SW1X) to £2,728 (Clarisford based in SW3).
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 SW3 by posting a job with HaMuch and we will send it to extension builders in SW3.
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 - £17,784

Two storey extension - £88,426

Build a timber frame extension - £26,284

Build a swimming pool - £81,284

Single storey extension - £60,680

Side return extension - £44,695

Install an RSJ - £2,484

Outbuilding - £10,284

Build a Mansard loft conversion - £52,284

Loft conversion - £36,413

Build a kitchen extension - £42,284

Hip to gable loft conversion - £42,284

Granny annexe - £87,284

Garden office - £10,284

Convert a Garage - £16,284

Garage - £18,784

Build a flat roof extension - £22,284

Build a dormer loft conversion - £42,284

Concrete foundations - £6,534

Convert a bungalow loft - £29,284

Convert a basement - £40,695