From £2,248
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in N14. No obligation free quotes ...
From £2,168
B J CULLEN BUILDERS are here to help customers who need an Extension Builder in N14. We offer a competitive rate to complete all your extension bui...
From £2,232
Relax... you have found a reliable extension builder in N14. Major Building Contractors Ltd is a friendly and reliable company based in N14 who con...
From £2,384
Need to find an Extension Builder near you for all your extension buildering work?
Sz Builders provides a local, trusted extension builderi...
From £2,912
Experienced extension builder ready to quote for your work. Render is the best extension builder in N14. No obligation free quotes and many happy c...
From £2,096
Experienced extension builder ready to quote for your work. Jhon is the best extension builder in N14. No obligation free quotes and many happy cus...
From £2,080
Member since August 2025
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,392
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...
From £2,512
skilled worker who specializes in completing a wide range of building and renovation projects
From £2,232
M & S Builders is a trusted extension builder serving customers in N14 and the surrounding area. Contact us to today to get a competitive quote for...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in N14 it ranges from £2,080 (Can design and Construction based in Ig11) to £2,912 (Render based in IG1).
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 N14 by posting a job with HaMuch and we will send it to extension builders in N14.
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 - £17,626

Two storey extension - £88,188

Build a timber frame extension - £26,126

Build a swimming pool - £81,126

Single storey extension - £57,512

Side return extension - £42,913

Install an RSJ - £2,326

Outbuilding - £10,126

Build a Mansard loft conversion - £52,126

Loft conversion - £34,928

Build a kitchen extension - £42,126

Hip to gable loft conversion - £42,126

Granny annexe - £87,126

Garden office - £10,126

Convert a Garage - £16,126

Garage - £18,626

Build a flat roof extension - £22,126

Build a dormer loft conversion - £42,126

Concrete foundations - £6,376

Convert a bungalow loft - £29,126

Convert a basement - £38,913