Range from the cheapest, mostly independent, £3 per hour and £230 per day (Surrey Hills Extend and Renovate Limited based in KT13) to the dearest, normally the best, £39 per hour and £264 per day (DITTON CONSTRUCTION LIMITED based in KT12).
Comparing hourly and daily rates of extension builders 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 - Click 'Get quotes' and describe your job and we will send it to your local extension builders for FREE.
Two Storey Extension plans approved, must be high end builder.
Extend rear of house by total of 10 sqm.
Convert loft to include 2 bed rooms and a bathroom.
We need extension builders like you to help local homeowners with their jobs.
| Job details | Estimate |
| Underpinning a house | £1720 |
| Build a two storey extension | £5735 |
| Build a timber frame extension | £5735 |
| Install a swimming pool | £3441 |
| Cost to build a single storey extension | £45880 |
| Cost to build a side return extension | £52762 |
| Install an RSJ | £1004 |
| Build an outbuilding | £2294 |
| Build a mansard loft conversion | £11470 |
| Cost of a loft conversion | £32116 |
| Build a kitchen extension | £11470 |
| Build a hip to gable loft conversion | £8602 |
| Build a granny annexe | £5735 |
| Build a garden office | £2294 |
| Convert a garage | £1147 |
| Build a new garage | £2294 |
| Build a flat roof extension | £1950 |
| Build a dormer loft conversion | £2294 |
| Lay a concrete foundation | £2294 |
| Convert a bungalow loft | £3441 |
| Basement conversion cost | £32116 |