From £17,436
L.D.Design&Build means a holistic approach to building, one simple way of finding everything you need for your building project under the ‘same r...
From £17,372
Need an Extension Builder in NN1? DAB & K&G Building Services has been helping local clients (20 mile radius) with their extension buildering jobs ...
From £17,116
Brickwork specialist with 30 years experience.
From repointing, small repairs up to building extensions and houses.
Stonework...
From £17,692
Relax... you have found a reliable extension builder in NN1. Wright Building is a friendly and reliable company based in NN1 who consider no job as...
From £17,100
M Home Renovations is an established extension buildering business in NN1. We come highly recommended and provide competitive quotes for your work....
From £17,612
Need to find an Extension Builder near you for all your extension buildering work?
The Builders - Northampton Limited provides a local, tru...
From £17,428
Fountain Construction Ltd is an established and experienced local extension builder in NN1. Please contact us for a free, no obligation quote and c...
From £17,748
Samrai Associates was founded by Hars Samrai in Northampton in order to provide clients with a prompt and robust Architectural Service. Over time m...
From £16,908
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...
From £17,364
Walsh Builders Ltd is an established and experienced local extension builder in NN1. Please contact us for a free, no obligation quote and competit...

Underpinning ranges from £16,908 (Artizan Roofing based in NN2) to £17,748 (Samrai Associates Limited based in NN3), but the final cost will depend on the method of underpinning used, how much of your foundations need underpinning and where you live.
Comparing extension builders estimates for underpinning gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
Get quotes to underpin your home in NN1 by posting a job with HaMuch and we will send it to extension builders in NN1.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Underpin A Building near Northampton | £35 | £239 |
| Underpin A Building near Wellingborough | £39 | £251 |
| Underpin A Building near Daventry | £31 | £230 |
| Underpin A Building near Rushden | £34 | £231 |
| Underpin A Building near Kettering | £34 | £237 |
| Underpin A Building near Milton Keynes | £39 | £263 |
| Underpin A Building near Market Harborough | £31 | £217 |
| Underpin A Building near Rugby | £31 | £224 |
| Underpin A Building near Bletchley | £39 | £265 |
| Underpin A Building 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 - £17,378

Two storey extension - £87,816

Build a timber frame extension - £25,878

Build a swimming pool - £80,878

Single storey extension - £52,552

Side return extension - £40,123

Install an RSJ - £2,078

Outbuilding - £9,878

Build a Mansard loft conversion - £51,878

Loft conversion - £32,603

Build a kitchen extension - £41,878

Hip to gable loft conversion - £41,878

Granny annexe - £86,878

Garden office - £9,878

Convert a Garage - £15,878

Garage - £18,378

Build a flat roof extension - £21,878

Build a dormer loft conversion - £41,878

Concrete foundations - £6,128

Convert a bungalow loft - £28,878

Convert a basement - £36,123