We send your job to ALL West Sussex extension builders
Available extension builders in West Sussex reply
Select your affordable West Sussex extension builder
Experienced extension builder ready to quote for your work. C C OLEARY CONSTRUCTION is the best extension builder in West Sussex. No obligation fre...
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
Trusted and professional extension builder in West Sussex. Experienced in all extension buildering work and keeping within budget and on quote. Str...
M Wesley General Builder & Property Maintenance is a trusted extension builder serving customers in West Sussex and the surrounding area. Contact u...
Need to find an Extension Builder near you for all your extension buildering work?
FIRST FORMAT BUILDING provides a local, trusted extensio...
From £21,992
Member since August 2026
H P Building Services Sussex is a one-stop solution for all your extension buildering needs. Establish over 10 years ago and covering 20 miles arou...
Relax... you have found a reliable extension builder in West Sussex. Haynes & Scott Developments is a friendly and reliable company based in West S...
Trusted and professional extension builder in West Sussex. Experienced in all extension buildering work and keeping within budget and on quote. S J...
Relax... you have found a reliable extension builder in West Sussex. ONE BUILD is a friendly and reliable company based in West Sussex who consider...
ACF Carpentry Ltd is an established and experienced local extension builder in West Sussex. Please contact us for a free, no obligation quote and c...

A flat roof extension ranges from the cheapest of £21,744 (ONE BUILD based in BN17) to the dearest of £22,200 (Alan Pacy Builder based in BN12), but these are just estimates. While they give you an idea of who will be better value, the best way to compare costs is to get real quotes.
Find out how much your flat roof extension will cost in West Sussex by posting a job with HaMuch. We'll send it to extension builders in West Sussex.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Build A Flat Roof Extension near Worthing | £35 | £249 |
| Build A Flat Roof Extension near Lancing | £36 | £249 |
| Build A Flat Roof Extension near Shoreham-by-Sea | £36 | £250 |
| Build A Flat Roof Extension near Rustington | £35 | £242 |
| Build A Flat Roof Extension near Littlehampton | £35 | £241 |
| Build A Flat Roof Extension near Arun | £35 | £241 |
| Build A Flat Roof Extension near Brighton | £35 | £253 |
| Build A Flat Roof Extension near Brighton and Hove | £35 | £252 |
| Build A Flat Roof Extension near Bognor Regis | £35 | £247 |
| Build A Flat Roof Extension near Burgess Hill | £36 | £256 |
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 - £17,452

Two storey extension - £87,928

Build a timber frame extension - £25,952

Build a swimming pool - £80,952

Single storey extension - £54,040

Side return extension - £40,960

Install an RSJ - £2,152

Outbuilding - £9,952

Build a Mansard loft conversion - £51,952

Loft conversion - £33,300

Build a kitchen extension - £41,952

Hip to gable loft conversion - £41,952

Granny annexe - £86,952

Garden office - £9,952

Convert a Garage - £15,952

Garage - £18,452

Build a flat roof extension - £21,952

Build a dormer loft conversion - £41,952

Concrete foundations - £6,202

Convert a bungalow loft - £28,952

Convert a basement - £36,960