RAINTON CONSTRUCTION LTD is an established and experienced local extension builder in Seaham. Please contact us for a free, no obligation quote and...
Trusted and professional extension builder in Seaham. Experienced in all extension buildering work and keeping within budget and on quote. DHB Buil...
Building Craft Ltd is an established extension buildering business in Seaham. We come highly recommended and provide competitive quotes for your wo...
Ian
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
LJP Roofing are here to help customers who need an Extension Builder in Seaham. We offer a competitive rate to complete all your extension builderi...
David Robertson
Trusted and professional extension builder in Seaham. Experienced in all extension buildering work and keeping within budget and on quote. David R...
STEVE MULVANEY BUILDING are here to help customers who need an Extension Builder in Seaham. We offer a competitive rate to complete all your extens...
From £2,304
A Kendal Builders (N/E) Limited is an established and experienced local extension builder in Seaham. Please contact us for a free, no obligation qu...
From £2,112
Our building services company Home Grown NE has been providing professional, trustworthy building services to customers throughout the North-East f...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Seaham it ranges from £2,008 (DHB Builders based in DH6) to £5,192 (David Robertson builders based in Sr4).
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 Seaham by posting a job with HaMuch and we will send it to extension builders in Seaham.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Seaham | £35 | £235 |
| Install An RSJ near Peterlee | £36 | £230 |
| Install An RSJ near Sunderland | £33 | £251 |
| Install An RSJ near Washington | £33 | £254 |
| Install An RSJ near Durham | £47 | £267 |
| Install An RSJ near Chester-le-Street | £35 | £242 |
| Install An RSJ near South Tyneside | £34 | £261 |
| Install An RSJ near Jarrow | £34 | £262 |
| Install An RSJ near Hartlepool | £40 | £236 |
| Install An RSJ near South Shields | £36 | £257 |
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 - £17,787

Two storey extension - £88,431

Build a timber frame extension - £26,287

Build a swimming pool - £81,287

Single storey extension - £60,742

Side return extension - £44,730

Install an RSJ - £2,487

Outbuilding - £10,287

Build a Mansard loft conversion - £52,287

Loft conversion - £36,442

Build a kitchen extension - £42,287

Hip to gable loft conversion - £42,287

Granny annexe - £87,287

Garden office - £10,287

Convert a Garage - £16,287

Garage - £18,787

Build a flat roof extension - £22,287

Build a dormer loft conversion - £42,287

Concrete foundations - £6,537

Convert a bungalow loft - £29,287

Convert a basement - £40,730