Range from the cheapest £20 per hour and £160 per day (HMS Property based in ST7) to the dearest £40 per hour and £250 per day (Highpride Developments Limited based in ST15).
Comparing hourly and daily rates of Extension Builder's 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.
See table for all Extension Builder rates in ST11
Experienced building company
| Job details | Estimate |
| Underpinning a house | £1440 |
| Build a two storey extension | £4801 |
| Build a timber frame extension | £4801 |
| Install a swimming pool | £2880 |
| Cost to build a single storey extension | £38405 |
| Cost to build a side return extension | £44166 |
| Install an RSJ | £840 |
| Build an outbuilding | £1920 |
| Build a mansard loft conversion | £9601 |
| Cost of a loft conversion | £26884 |
| Build a kitchen extension | £9601 |
| Build a hip to gable loft conversion | £7201 |
| Build a granny annexe | £4801 |
| Build a garden office | £1920 |
| Convert a garage | £960 |
| Build a flat roof extension | £1632 |
| Build a dormer loft conversion | £1920 |
| Lay a concrete foundation | £1920 |
| Convert a bungalow loft | £2880 |
| Basement conversion cost | £26884 |