From £2,248
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in TW12. No obligation free quotes...
1 review
From £2,392
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...
"Did callout made safe my elctrical work thanks" - reviewed 16/05/23, REECYRUSSO
From £2,224
Need the extension buildering job done quickly without breaking the bank? SH Enterprise offer fast, reliable, and affordable extension buildering s...
From £2,512
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £2,592
Need an Extension Builder in TW12? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many ye...
From £2,392
Need an Extension Builder in TW12? VA Structures has been helping local clients (10 mile radius) with their extension buildering jobs for many year...
From £2,480
Trusted and professional extension builder in TW12. Experienced in all extension buildering work and keeping within budget and on quote. DC Build &...
From £2,352
I am a qualified, builder, electrician and plumber. I have been working in the construction industry for over 23 years and have built everything fr...
From £2,504
Hi we have 15 years of experience in building and construction industry our specialization is bathrooms and renovations please have a look at the w...
From £3,224
Buci builders ltd is a trusted extension builder serving customers in TW12 and the surrounding area. Contact us to today to get a competitive quote...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in TW12 it ranges from £2,224 (SH Enterprise based in EC1V) to £3,224 (Buci builders ltd based in SE27).
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 TW12 by posting a job with HaMuch and we will send it to extension builders in TW12.
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 - £17,792

Two storey extension - £88,438

Build a timber frame extension - £26,292

Build a swimming pool - £81,292

Single storey extension - £60,840

Side return extension - £44,785

Install an RSJ - £2,492

Outbuilding - £10,292

Build a Mansard loft conversion - £52,292

Loft conversion - £36,488

Build a kitchen extension - £42,292

Hip to gable loft conversion - £42,292

Granny annexe - £87,292

Garden office - £10,292

Convert a Garage - £16,292

Garage - £18,792

Build a flat roof extension - £22,292

Build a dormer loft conversion - £42,292

Concrete foundations - £6,542

Convert a bungalow loft - £29,292

Convert a basement - £40,785