From £17,548
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in Kilburn. No obligation free quo...
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 £17,700
Relax... you have found a reliable extension builder in Kilburn. Derryard Construction Ltd is a friendly and reliable company based in Kilburn who ...
From £17,468
B J CULLEN BUILDERS are here to help customers who need an Extension Builder in Kilburn. We offer a competitive rate to complete all your extension...
From £17,532
Relax... you have found a reliable extension builder in Kilburn. Major Building Contractors Ltd is a friendly and reliable company based in Kilburn...
From £17,684
Need to find an Extension Builder near you for all your extension buildering work?
Sz Builders provides a local, trusted extension builderi...
From £18,212
Experienced extension builder ready to quote for your work. Render is the best extension builder in Kilburn. No obligation free quotes and many hap...
From £17,396
Experienced extension builder ready to quote for your work. Jhon is the best extension builder in Kilburn. No obligation free quotes and many happy...
From £17,380
Member since August 2025
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £17,692
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...

Underpinning ranges from £17,380 (Can design and Construction based in Ig11) to £18,212 (Render based in IG1), 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 Kilburn by posting a job with HaMuch and we will send it to extension builders in Kilburn.
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 - £17,642

Two storey extension - £88,214

Build a timber frame extension - £26,142

Build a swimming pool - £81,142

Single storey extension - £57,848

Side return extension - £43,102

Install an RSJ - £2,342

Outbuilding - £10,142

Build a Mansard loft conversion - £52,142

Loft conversion - £35,085

Build a kitchen extension - £42,142

Hip to gable loft conversion - £42,142

Granny annexe - £87,142

Garden office - £10,142

Convert a Garage - £16,142

Garage - £18,642

Build a flat roof extension - £22,142

Build a dormer loft conversion - £42,142

Concrete foundations - £6,392

Convert a bungalow loft - £29,142

Convert a basement - £39,102