From £42,450
Need to find an Extension Builder near you for all your extension buildering work?
Main Construction provides a local, trusted extension bu...
From £36,060
Need an Extension Builder in Southwater? MPS Home Improvements Ltd has been helping local clients (20 mile radius) with their extension buildering ...
From £41,190
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £37,410
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...
From £40,560
Need to find an Extension Builder near you for all your extension buildering work?
DPP Construction (David Price Partnership) provides a lo...
From £39,390
R S Construction (Surrey) is an established extension buildering business in Southwater. We come highly recommended and provide competitive quotes ...
From £37,860
We are a family run business we 40 years experience delivering multiple projects from new developments . Extension. Loft conversion. Including foun...
From £38,760
, BN18
Futureways Design and Build are here to help customers who need an Extension Builder in Southwater. We offer a competitive rate to complete all you...
From £39,750
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £42,090
Garage Door Repairs is an established extension buildering business in Southwater. We come highly recommended and provide competitive quotes for yo...

Comparing extension builders estimates for a Convert a basement gives you an idea of who will be better value but the best way to compare costs is to get actual quotes.
What to do - Get rates and quotes for the cost to convert a basement in Southwater by posting a job with HaMuch and we will send it to extension builders in Southwater.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Convert A Basement near Horsham | £38 | £265 |
| Convert A Basement near Mid Sussex | £35 | £261 |
| Convert A Basement near Crawley | £38 | £255 |
| Convert A Basement near Burgess Hill | £36 | £240 |
| Convert A Basement near Haywards Heath | £35 | £256 |
| Convert A Basement near Horley | £38 | £258 |
| Convert A Basement near Shoreham-by-Sea | £36 | £250 |
| Convert A Basement near Lancing | £37 | £251 |
| Convert A Basement near Reigate | £40 | £270 |
| Convert A Basement near East Grinstead | £37 | £259 |
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 - £17,682

Two storey extension - £88,274

Build a timber frame extension - £26,182

Build a swimming pool - £81,182

Single storey extension - £58,648

Side return extension - £43,552

Install an RSJ - £2,382

Outbuilding - £10,182

Build a Mansard loft conversion - £52,182

Loft conversion - £35,460

Build a kitchen extension - £42,182

Hip to gable loft conversion - £42,182

Granny annexe - £87,182

Garden office - £10,182

Convert a Garage - £16,182

Garage - £18,682

Build a flat roof extension - £22,182

Build a dormer loft conversion - £42,182

Concrete foundations - £6,432

Convert a bungalow loft - £29,182

Convert a basement - £39,552