Alan Hicks
Need to find an Extension Builder near you for all your extension buildering work?
A G Hicks Building Services provides a local, trusted ex...
Trusted and professional extension builder in NN3. Experienced in all extension buildering work and keeping within budget and on quote. Northants G...
M Home Renovations is an established extension buildering business in NN3. We come highly recommended and provide competitive quotes for your work....
Walsh Builders Ltd is an established and experienced local extension builder in NN3. Please contact us for a free, no obligation quote and competit...
Relax... you have found a reliable extension builder in NN3. Wright Building is a friendly and reliable company based in NN3 who consider no job as...
Need an Extension Builder in NN3? DAB & K&G Building Services has been helping local clients (20 mile radius) with their extension buildering jobs ...
Samrai Associates was founded by Hars Samrai in Northampton in order to provide clients with a prompt and robust Architectural Service. Over time m...
Neil Donlevy
Need to find an Extension Builder near you for all your extension buildering work?
The Builders - Northampton Limited provides a local, tru...
Paul Watts
We have a great team behind us, we offer friendly, competitive and professional service. With years of experience among the trades, there's not muc...
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...

How much RSJs cost for supply and installation varies depending on the size, type and load-bearing properties, but in NN3 it ranges from £1,608 (Artizan Roofing based in NN2) to £2,448 (Samrai Associates Limited based in NN3).
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 NN3 by posting a job with HaMuch and we will send it to extension builders in NN3.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Install An RSJ near Northampton | £35 | £239 |
| Install An RSJ near Wellingborough | £39 | £251 |
| Install An RSJ near Rushden | £34 | £231 |
| Install An RSJ near Kettering | £34 | £237 |
| Install An RSJ near Daventry | £31 | £230 |
| Install An RSJ near Market Harborough | £31 | £217 |
| Install An RSJ near Milton Keynes | £39 | £263 |
| Install An RSJ near Corby | £30 | £214 |
| Install An RSJ near Bedford | £45 | £278 |
| Install An RSJ near South Bedfordshire | £45 | £278 |
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 - £17,371

Two storey extension - £87,807

Build a timber frame extension - £25,871

Build a swimming pool - £80,871

Single storey extension - £52,424

Side return extension - £40,051

Install an RSJ - £2,071

Outbuilding - £9,871

Build a Mansard loft conversion - £51,871

Loft conversion - £32,543

Build a kitchen extension - £41,871

Hip to gable loft conversion - £41,871

Granny annexe - £86,871

Garden office - £9,871

Convert a Garage - £15,871

Garage - £18,371

Build a flat roof extension - £21,871

Build a dormer loft conversion - £41,871

Concrete foundations - £6,121

Convert a bungalow loft - £28,871

Convert a basement - £36,051