From £2,400
Experienced extension builder ready to quote for your work. IM Construction is the best extension builder in Harlesden. No obligation free quotes a...
From £3,816
Harlesden London, NW10
Over 20 years experience
Client focussed and driven
Personal planning and completion of work
Warranty ...
From £2,584
Need an Extension Builder in Harlesden? C & I has been helping local clients (5 mile radius) with their extension buildering jobs for many years. G...
From £2,240
Harlesden Greater London, NW10
T&M Property Services was established in 2000. We are quality, friendly affordable general builders. We undertake large projects like loft conversi...
From £2,520
Need to find an Extension Builder near you for all your extension buildering work?
Byron Elie provides a local, trusted extension builderin...
From £2,496
Harlesden Greater London, NW10
We offer a bespoke domestic build and design service.
From £2,104
V.S.P is a trusted extension builder serving customers in Harlesden and the surrounding area. Contact us to today to get a competitive quote for ex...
From £2,352
Harlesden, NW10
SDM Services is an established extension buildering business in Harlesden. We come highly recommended and provide competitive quotes for your work....
From £2,344
Experienced extension builder ready to quote for your work. Khetani Builders (UK) Ltd is the best extension builder in Harlesden. No obligation fre...
From £2,280
Harlesden, NW10
Miyard Ltd is a trusted extension builder serving customers in Harlesden and the surrounding area. Contact us to today to get a competitive quote f...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Harlesden it ranges from £2,104 (V.S.P based in NW10) to £3,816 (GasHeat based in NW10).
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 Harlesden by posting a job with HaMuch and we will send it to extension builders in Harlesden.
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 - £17,814

Two storey extension - £88,470

Build a timber frame extension - £26,314

Build a swimming pool - £81,314

Single storey extension - £61,272

Side return extension - £45,028

Install an RSJ - £2,514

Outbuilding - £10,314

Build a Mansard loft conversion - £52,314

Loft conversion - £36,690

Build a kitchen extension - £42,314

Hip to gable loft conversion - £42,314

Granny annexe - £87,314

Garden office - £10,314

Convert a Garage - £16,314

Garage - £18,814

Build a flat roof extension - £22,314

Build a dormer loft conversion - £42,314

Concrete foundations - £6,564

Convert a bungalow loft - £29,314

Convert a basement - £41,028