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 £17,100
M Home Renovations is an established extension buildering business in NN3. We come highly recommended and provide competitive quotes for your work....
From £17,116
Brickwork specialist with 30 years experience.
From repointing, small repairs up to building extensions and houses.
Stonework...
From £17,428
Fountain Construction Ltd is an established and experienced local extension builder in NN3. Please contact us for a free, no obligation quote and c...
From £17,412
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,044
Need to find an Extension Builder near you for all your extension buildering work?
A G Hicks Building Services provides a local, trusted ex...
From £17,372
Need an Extension Builder in NN3? DAB & K&G Building Services has been helping local clients (20 mile radius) with their extension buildering jobs ...
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 £17,460
Trusted and professional extension builder in NN3. Experienced in all extension buildering work and keeping within budget and on quote. Northants G...
From £17,364
Walsh Builders Ltd is an established and experienced local extension builder in NN3. Please contact us for a free, no obligation quote and competit...

Underpinning ranges from £17,044 (A G Hicks Building Services based in NN3) 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 NN3 by posting a job with HaMuch and we will send it to extension builders in NN3.
| 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 Rushden | £34 | £231 |
| Underpin A Building near Kettering | £34 | £237 |
| Underpin A Building near Daventry | £31 | £230 |
| Underpin A Building near Market Harborough | £31 | £217 |
| Underpin A Building near Milton Keynes | £39 | £263 |
| Underpin A Building near Corby | £30 | £214 |
| Underpin A Building near South Bedfordshire | £45 | £278 |
| Underpin A Building near Bedford | £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 - £17,348

Two storey extension - £87,772

Build a timber frame extension - £25,848

Build a swimming pool - £80,848

Single storey extension - £51,960

Side return extension - £39,790

Install an RSJ - £2,048

Outbuilding - £9,848

Build a Mansard loft conversion - £51,848

Loft conversion - £32,325

Build a kitchen extension - £41,848

Hip to gable loft conversion - £41,848

Granny annexe - £86,848

Garden office - £9,848

Convert a Garage - £15,848

Garage - £18,348

Build a flat roof extension - £21,848

Build a dormer loft conversion - £41,848

Concrete foundations - £6,098

Convert a bungalow loft - £28,848

Convert a basement - £35,790