Range from the cheapest, mostly independent, £30 per hour and £200 per day (Philpot Construction based in EN9) to the dearest, normally the best, £39 per hour and £250 per day (Nouvell Decor based in IG9).
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.
Groundworkers construction
Extension , loft conversion
Loft extension and ground floor extension
We need extension builders like you to help local homeowners with their jobs.
| Job details | Estimate |
| Underpinning a house | £1689 |
| Build a two storey extension | £5632 |
| Build a timber frame extension | £5632 |
| Install a swimming pool | £3379 |
| Cost to build a single storey extension | £45052 |
| Cost to build a side return extension | £51810 |
| Install an RSJ | £986 |
| Build an outbuilding | £2253 |
| Build a mansard loft conversion | £11263 |
| Cost of a loft conversion | £31537 |
| Build a kitchen extension | £11263 |
| Build a hip to gable loft conversion | £8447 |
| Build a granny annexe | £5632 |
| Build a garden office | £2253 |
| Convert a garage | £1126 |
| Build a new garage | £2253 |
| Build a flat roof extension | £1915 |
| Build a dormer loft conversion | £2253 |
| Lay a concrete foundation | £2253 |
| Convert a bungalow loft | £3379 |
| Basement conversion cost | £31537 |