From £87,048
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in South East. No obligation free ...
From £86,984
JK Doors is a trusted extension builder serving customers in South East and the surrounding area. Contact us to today to get a competitive quote fo...
From £87,192
NIECEIC / NAAPIT GASSAFE WATER REGULATIONS We offer services towards completion of high end construction projects to dis...
From £87,392
Need an Extension Builder in South East? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for m...
From £87,312
skilled worker who specializes in completing a wide range of building and renovation projects
From £87,616
HOUSE BUILDING SERVICES LIMITED is a trusted extension builder serving customers in South East and the surrounding area. Contact us to today to get...
From £86,888
Member since April 2025
Trusted and professional extension builder in South East. Experienced in all extension buildering work and keeping within budget and on quote. GR M...
From £87,312
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £87,200
Relax... you have found a reliable extension builder in South East. Derryard Construction Ltd is a friendly and reliable company based in South Eas...
From £86,968
B J CULLEN BUILDERS are here to help customers who need an Extension Builder in South East. We offer a competitive rate to complete all your extens...

Building a granny annexe ranges from £86,888 (GR MAINTENANCE LTD based in IG11) to £87,616 (HOUSE BUILDING SERVICES LIMITED based in DA16), but these are just estimates that can help give you an idea of who will be better value in your area.
The best thing to do is to get quotes to build a granny annexe in South East by posting a job with HaMuch. We will send it to extension builders in South East who will be happy to help you.
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 - £17,691

Two storey extension - £88,287

Build a timber frame extension - £26,191

Build a swimming pool - £81,191

Single storey extension - £58,824

Side return extension - £43,651

Install an RSJ - £2,391

Outbuilding - £10,191

Build a Mansard loft conversion - £52,191

Loft conversion - £35,543

Build a kitchen extension - £42,191

Hip to gable loft conversion - £42,191

Granny annexe - £87,191

Garden office - £10,191

Convert a Garage - £16,191

Garage - £18,691

Build a flat roof extension - £22,191

Build a dormer loft conversion - £42,191

Concrete foundations - £6,441

Convert a bungalow loft - £29,191

Convert a basement - £39,651