From £17,548
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in Islington. No obligation free q...
From £17,564
Hyde Building Ltd are here to help customers who need an Extension Builder in Islington. We offer a competitive rate to complete all your extension...
From £18,004
At Ferdas Design & Build Ltd we have been fitting bespoke bathrooms since 2013. We pride ourselves on being the go-to bathroom fitters for discerni...
1 review
From £17,692
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...
"Did callout made safe my elctrical work thanks" - reviewed 16/05/23, REECYRUSSO
From £17,524
Need the extension buildering job done quickly without breaking the bank? SH Enterprise offer fast, reliable, and affordable extension buildering s...
From £17,812
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,892
Need an Extension Builder in Islington? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for ma...
From £17,692
Need an Extension Builder in Islington? VA Structures has been helping local clients (10 mile radius) with their extension buildering jobs for many...
From £17,780
Trusted and professional extension builder in Islington. Experienced in all extension buildering work and keeping within budget and on quote. DC Bu...
From £17,652
I am a qualified, builder, electrician and plumber. I have been working in the construction industry for over 23 years and have built everything fr...

Underpinning ranges from £17,524 (SH Enterprise based in EC1V) to £18,004 (Ferdas Design & Build Ltd based in W3), 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 Islington by posting a job with HaMuch and we will send it to extension builders in Islington.
"Underpin a building" - N7, job posted 01/01/70
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 - £17,716

Two storey extension - £88,324

Build a timber frame extension - £26,216

Build a swimming pool - £81,216

Single storey extension - £59,320

Side return extension - £43,930

Install an RSJ - £2,416

Outbuilding - £10,216

Build a Mansard loft conversion - £52,216

Loft conversion - £35,775

Build a kitchen extension - £42,216

Hip to gable loft conversion - £42,216

Granny annexe - £87,216

Garden office - £10,216

Convert a Garage - £16,216

Garage - £18,716

Build a flat roof extension - £22,216

Build a dormer loft conversion - £42,216

Concrete foundations - £6,466

Convert a bungalow loft - £29,216

Convert a basement - £39,930