From £12,064
We build Lofts. We build Extensions. We undertake conversions. Our Terms and conditions apply as shown in our starter packs.
From £10,200
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £9,920
Experienced extension builder ready to quote for your work. Kovacs Construction Ltd is the best extension builder in Finsbury. No obligation free q...
From £10,272
At Kovacs Construction, you can rely on our talented builders and engineers to deliver unrivalled building services solutions. Let us show you our ...
From £10,272
Experienced extension builder ready to quote for your work. Oxford West is the best extension builder in Finsbury. No obligation free quotes and ma...
From £10,040
JM Building Services is a trusted extension builder serving customers in Finsbury and the surrounding area. Contact us to today to get a competitiv...
From £10,392
We have the experience and knowledge to carry out any project, big or small. Our team of experts thoroughly plan the budget and manage your projec...
From £10,216
Buildwiser is a trusted extension builder serving customers in Finsbury and the surrounding area. Contact us to today to get a competitive quote fo...
From £10,408
Centaurus is one of North London's most experienced builders. With expert craftsmanship, attention to detail, the right materials we are committed ...
From £10,408
Trusted and professional extension builder in Finsbury. Experienced in all extension buildering work and keeping within budget and on quote. Cedar ...

Outbuilding costs in Finsbury range from the cheapest of £9,920 (Kovacs Construction Ltd based in EC1N) to the dearest of £12,064 (Q Lofts and Extensions based in EC1R), but these are just estimates.
Comparing extension builders estimates for building an outbuilding 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 build an outbuilding in Finsbury by posting a job with HaMuch and we will send it to extension builders.
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 - £17,919

Two storey extension - £88,629

Build a timber frame extension - £26,419

Build a swimming pool - £81,419

Single storey extension - £63,384

Side return extension - £46,216

Install an RSJ - £2,619

Outbuilding - £10,419

Build a Mansard loft conversion - £52,419

Loft conversion - £37,680

Build a kitchen extension - £42,419

Hip to gable loft conversion - £42,419

Granny annexe - £87,419

Garden office - £10,419

Convert a Garage - £16,419

Garage - £18,919

Build a flat roof extension - £22,419

Build a dormer loft conversion - £42,419

Concrete foundations - £6,669

Convert a bungalow loft - £29,419

Convert a basement - £42,216