From £2,112
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 £1,360
We provide expert advice on building defects and cost effective environmental friendly solutions throughout the North East of England. Our bu...
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 £2,032
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...
From £2,008
Trusted and professional extension builder in Seaham. Experienced in all extension buildering work and keeping within budget and on quote. DHB Buil...
From £2,112
Our building services company Home Grown NE has been providing professional, trustworthy building services to customers throughout the North-East f...
From £2,136
Building Craft Ltd is an established extension buildering business in Seaham. We come highly recommended and provide competitive quotes for your wo...
From £2,184
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £5,192
Trusted and professional extension builder in Seaham. Experienced in all extension buildering work and keeping within budget and on quote. David R...
From £2,304
RAINTON CONSTRUCTION LTD is an established and experienced local extension builder in Seaham. Please contact us for a free, no obligation quote and...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Seaham it ranges from £1,360 (Dry Tec 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 | £34 | £229 |
| Install An RSJ near Peterlee | £35 | £222 |
| Install An RSJ near Sunderland | £33 | £251 |
| Install An RSJ near Washington | £33 | £251 |
| 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 | £261 |
| 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 - £17,674

Two storey extension - £88,262

Build a timber frame extension - £26,174

Build a swimming pool - £81,174

Single storey extension - £58,488

Side return extension - £43,462

Install an RSJ - £2,374

Outbuilding - £10,174

Build a Mansard loft conversion - £52,174

Loft conversion - £35,385

Build a kitchen extension - £42,174

Hip to gable loft conversion - £42,174

Granny annexe - £87,174

Garden office - £10,174

Convert a Garage - £16,174

Garage - £18,674

Build a flat roof extension - £22,174

Build a dormer loft conversion - £42,174

Concrete foundations - £6,424

Convert a bungalow loft - £29,174

Convert a basement - £39,462