From £2,192
Member since August 2026
H P Building Services Sussex is a one-stop solution for all your extension buildering needs. Establish over 10 years ago and covering 20 miles arou...
From £2,216
Trusted and professional extension builder in Seaford. Experienced in all extension buildering work and keeping within budget and on quote. Good Co...
From £2,192
Experienced extension builder ready to quote for your work. Brighton Marina Hand Car Wash is the best extension builder in Seaford. No obligation f...
From £2,272
Relax... you have found a reliable extension builder in Seaford. R & G Construction Brighton Ltd is a friendly and reliable company based in Seafor...
From £1,968
Experienced extension builder ready to quote for your work. Graeme Davies Plumbing and Heating is the best extension builder in Seaford. No obligat...
From £3,320
Experienced extension builder ready to quote for your work. CITY BUILDING SERVICES LIMITED is the best extension builder in Seaford. No obligation ...
From £1,944
Relax... you have found a reliable extension builder in Seaford. Ljo Brickwork, Landscapes and General Building is a friendly and reliable company ...
From £1,960
Need to find an Extension Builder near you for all your extension buildering work?
S F CONSTRUCTION provides a local, trusted extension bu...
From £2,056
CAMBRIDGE BUILDING SERVICES is a trusted extension builder serving customers in Seaford and the surrounding area. Contact us to today to get a comp...
From £2,136
ACF Carpentry Ltd is an established and experienced local extension builder in Seaford. Please contact us for a free, no obligation quote and compe...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in Seaford it ranges from £1,944 (Ljo Brickwork, Landscapes and General Building based in TN38) to £3,320 (CITY BUILDING SERVICES LIMITED based in BN2).
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 Seaford by posting a job with HaMuch and we will send it to extension builders in Seaford.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Seaford | £34 | £243 |
| Install An RSJ near Eastbourne | £32 | £245 |
| Install An RSJ near Hailsham | £31 | £243 |
| Install An RSJ near Brighton and Hove | £35 | £251 |
| Install An RSJ near Brighton | £35 | £251 |
| Install An RSJ near Wealden | £35 | £256 |
| Install An RSJ near Burgess Hill | £36 | £240 |
| Install An RSJ near Shoreham-by-Sea | £36 | £250 |
| Install An RSJ near Bexhill-on-Sea | £31 | £243 |
| Install An RSJ near Haywards Heath | £35 | £256 |
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 - £17,526

Two storey extension - £88,038

Build a timber frame extension - £26,026

Build a swimming pool - £81,026

Single storey extension - £55,512

Side return extension - £41,788

Install an RSJ - £2,226

Outbuilding - £10,026

Build a Mansard loft conversion - £52,026

Loft conversion - £33,990

Build a kitchen extension - £42,026

Hip to gable loft conversion - £42,026

Granny annexe - £87,026

Garden office - £10,026

Convert a Garage - £16,026

Garage - £18,526

Build a flat roof extension - £22,026

Build a dormer loft conversion - £42,026

Concrete foundations - £6,276

Convert a bungalow loft - £29,026

Convert a basement - £37,788