From £87,048
Experienced extension builder ready to quote for your work. J&J Building Solutions is the best extension builder in DA18. No obligation free quotes...
From £87,184
Experienced extension builder ready to quote for your work. CC&D BUILDING LTD is the best extension builder in DA18. No obligation free quotes and ...
From £87,560
Our homes need to be regularly maintained and from time to time they need to be rejuvenated, modernised and enhanced. When it comes to building wor...
From £87,096
Experienced extension builder ready to quote for your work. Mr is the best extension builder in DA18. No obligation free quotes and many happy cust...
From £86,984
JK Doors is a trusted extension builder serving customers in DA18 and the surrounding area. Contact us to today to get a competitive quote for exte...
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 DA18? Samuele Paolini has been helping local clients (5 mile radius) with their extension buildering jobs for many ye...
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 DA18 and the surrounding area. Contact us to today to get a com...
From £86,888
Member since April 2025
Trusted and professional extension builder in DA18. Experienced in all extension buildering work and keeping within budget and on quote. GR MAINTEN...

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 DA18 by posting a job with HaMuch. We will send it to extension builders in DA18 who will be happy to help you.
"Granny annexe" - ABBEY WOOD, job posted 08/01/24
| Borough in London |
|---|
| Granny Annexe in Erith |
| Granny Annexe in Belvedere |
| Granny Annexe in Abbey Wood |
| Granny Annexe in Thamesmead |
| Granny Annexe in Barnehurst |
| Granny Annexe in Crayford |
| Granny Annexe in Welling |
| Granny Annexe in Bexleyheath |
| Granny Annexe in Woolwich |
| Granny Annexe in Rainham |
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 - £17,727

Two storey extension - £88,341

Build a timber frame extension - £26,227

Build a swimming pool - £81,227

Single storey extension - £59,544

Side return extension - £44,056

Install an RSJ - £2,427

Outbuilding - £10,227

Build a Mansard loft conversion - £52,227

Loft conversion - £35,880

Build a kitchen extension - £42,227

Hip to gable loft conversion - £42,227

Granny annexe - £87,227

Garden office - £10,227

Convert a Garage - £16,227

Garage - £18,727

Build a flat roof extension - £22,227

Build a dormer loft conversion - £42,227

Concrete foundations - £6,477

Convert a bungalow loft - £29,227

Convert a basement - £40,056