From £2,624
ARCHWAY DESIGN+BUILD LTD are here to help customers who need an Extension Builder in Highgate. We offer a competitive rate to complete all your ext...
From £2,248
Need an Extension Builder in Highgate? Avocado Sweets Design Studio has been helping local clients (5 mile radius) with their extension buildering ...
From £2,328
RAM Build Construction Ltd is an established and experienced local extension builder in Highgate. Please contact us for a free, no obligation quote...
From £2,536
We make the adage ‘House is where the heart is’, a reality for the house-owners.We are an empathetic housebuilder that delivers elegance and du...
From £2,496
We pride ourselves on our ability to provide unmatched construction, renovation and refurbishment services to homeowners, designers and architects ...
From £2,088
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,392
SJ Expert Building Services are here to help customers who need an Extension Builder in Highgate. We offer a competitive rate to complete all your ...
From £2,280
Trusted and professional extension builder in Highgate. Experienced in all extension buildering work and keeping within budget and on quote. Arunde...
From £2,160
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,320
We have worked with homeowners all over London and designers to produce work we think you'll love. Our past projects include both new construction ...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Highgate it ranges from £2,088 (Warren House Construction Ltd based in N19) to £2,624 (ARCHWAY DESIGN+BUILD LTD based in N19).
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 Highgate by posting a job with HaMuch and we will send it to extension builders in Highgate.
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 - £17,647

Two storey extension - £88,221

Build a timber frame extension - £26,147

Build a swimming pool - £81,147

Single storey extension - £57,944

Side return extension - £43,156

Install an RSJ - £2,347

Outbuilding - £10,147

Build a Mansard loft conversion - £52,147

Loft conversion - £35,130

Build a kitchen extension - £42,147

Hip to gable loft conversion - £42,147

Granny annexe - £87,147

Garden office - £10,147

Convert a Garage - £16,147

Garage - £18,647

Build a flat roof extension - £22,147

Build a dormer loft conversion - £42,147

Concrete foundations - £6,397

Convert a bungalow loft - £29,147

Convert a basement - £39,156