From £86,936
Trusted and professional extension builder in RH12. Experienced in all extension buildering work and keeping within budget and on quote. M + H Buil...
From £86,952
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £87,416
Established in 2005, GreenBuild provides a sustainable high-end construction service throughout Sussex, Surrey and the surrounding areas. Our exper...
From £87,312
Trusted and professional extension builder in RH12. Experienced in all extension buildering work and keeping within budget and on quote. CadLine Lt...
From £86,984
Trusted and professional extension builder in RH12. Experienced in all extension buildering work and keeping within budget and on quote. Design-a-l...
From £87,056
Capital lofts are a design and build construction company based in Horsham, we provide high quality workmanship from architectural drawings to a f...
From £86,624
Hi I'm an independent patio and drive way specialist with over 10 years experence. My reasonable prices and my professional work is every reason to...
From £87,136
G & R Homes is an established and experienced local extension builder in RH12. Please contact us for a free, no obligation quote and competitive ra...
From £87,136
AWS Home Improvements is an established extension buildering business in RH12. We come highly recommended and provide competitive quotes for your w...
From £87,264
Need an Extension Builder in RH12? Michael & Co has been helping local clients (20 mile radius) with their extension buildering jobs for many years...

Building a granny annexe ranges from £86,624 (Farley Patio & Paving based in RH13) to £87,416 (GreenBuild based in RH13), 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 RH12 by posting a job with HaMuch. We will send it to extension builders in RH12 who will be happy to help you.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Granny Annexe near Horsham | £32 | £226 |
| Granny Annexe near Crawley | £33 | £227 |
| Granny Annexe near Mid Sussex | £30 | £224 |
| Granny Annexe near Horley | £35 | £234 |
| Granny Annexe near Haywards Heath | £30 | £222 |
| Granny Annexe near Burgess Hill | £31 | £208 |
| Granny Annexe near Reigate | £36 | £238 |
| Granny Annexe near Redhill | £36 | £236 |
| Granny Annexe near Great Bookham | £36 | £235 |
| Granny Annexe near East Grinstead | £32 | £220 |
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 - £17,582

Two storey extension - £88,122

Build a timber frame extension - £26,082

Build a swimming pool - £81,082

Single storey extension - £56,632

Side return extension - £42,418

Install an RSJ - £2,282

Outbuilding - £10,082

Build a Mansard loft conversion - £52,082

Loft conversion - £34,515

Build a kitchen extension - £42,082

Hip to gable loft conversion - £42,082

Granny annexe - £87,082

Garden office - £10,082

Convert a Garage - £16,082

Garage - £18,582

Build a flat roof extension - £22,082

Build a dormer loft conversion - £42,082

Concrete foundations - £6,332

Convert a bungalow loft - £29,082

Convert a basement - £38,418