From £87,048
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in SW4. No obligation free quotes ...
From £87,096
Experienced extension builder ready to quote for your work. Mr is the best extension builder in SW4. No obligation free quotes and many happy custo...
From £86,984
JK Doors is a trusted extension builder serving customers in SW4 and the surrounding area. Contact us to today to get a competitive quote for exten...
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 SW4? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many yea...
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 SW4 and the surrounding area. Contact us to today to get a comp...
From £86,888
Member since April 2025
Trusted and professional extension builder in SW4. Experienced in all extension buildering work and keeping within budget and on quote. GR MAINTENA...
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 SW4. Derryard Construction Ltd is a friendly and reliable company based in SW4 who consider...

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 SW4 by posting a job with HaMuch. We will send it to extension builders in SW4 who will be happy to help you.
| Borough in London |
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| Granny Annexe in Clapham |
| Granny Annexe in Brixton |
| Granny Annexe in Nine Elms |
| Granny Annexe in Balham |
| Granny Annexe in Stockwell |
| Granny Annexe in Battersea |
| Granny Annexe in Herne Hill |
| Granny Annexe in Pimlico |
| Granny Annexe in Camberwell |
| Granny Annexe in Lambeth |
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 - £17,704

Two storey extension - £88,306

Build a timber frame extension - £26,204

Build a swimming pool - £81,204

Single storey extension - £59,080

Side return extension - £43,795

Install an RSJ - £2,404

Outbuilding - £10,204

Build a Mansard loft conversion - £52,204

Loft conversion - £35,663

Build a kitchen extension - £42,204

Hip to gable loft conversion - £42,204

Granny annexe - £87,204

Garden office - £10,204

Convert a Garage - £16,204

Garage - £18,704

Build a flat roof extension - £22,204

Build a dormer loft conversion - £42,204

Concrete foundations - £6,454

Convert a bungalow loft - £29,204

Convert a basement - £39,795