From £2,248
Flow-Right Construction is an established extension buildering business in Walthamstow. We come highly recommended and provide competitive quotes f...
From £2,144
Walthamstow London, E17
Italian Home Renovation are here to help customers who need an Extension Builder in Walthamstow. We offer a competitive rate to complete all your e...
From £2,688
Specialized in advising and implement the choices of the most demanding customers. From inerior design with also crafted tailored solutions and the...
From £2,248
Walthamstow, E17
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,336
Walthamstow Londonderry, E17
London Airports Taxi are here to help customers who need an Extension Builder in Walthamstow. We offer a competitive rate to complete all your exte...
From £3,512
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £4,336
Walthamstow London, E17
We are one of the leading specialists company in London and we believe in providing a wide range of services to many of our clients. We have extens...
From £2,264
Gold & Berg are a London-based, international construction services company and are a leading builder in diverse market segments. The company has e...
From £2,416
Walthamstow, E17
Relax... you have found a reliable extension builder in Walthamstow. Amwell Construction Ltd is a friendly and reliable company based in Walthamsto...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Walthamstow it ranges from £2,144 (Italian Home Renovation based in e17) to £4,336 (Iservices-uk Ltd based in E17).
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 Walthamstow by posting a job with HaMuch and we will send it to extension builders in Walthamstow.
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 - £17,938

Two storey extension - £88,658

Build a timber frame extension - £26,438

Build a swimming pool - £81,438

Single storey extension - £63,768

Side return extension - £46,432

Install an RSJ - £2,638

Outbuilding - £10,438

Build a Mansard loft conversion - £52,438

Loft conversion - £37,860

Build a kitchen extension - £42,438

Hip to gable loft conversion - £42,438

Granny annexe - £87,438

Garden office - £10,438

Convert a Garage - £16,438

Garage - £18,938

Build a flat roof extension - £22,438

Build a dormer loft conversion - £42,438

Concrete foundations - £6,688

Convert a bungalow loft - £29,438

Convert a basement - £42,432