Extension builder estimates (based on hourly rates) to build a single storey extension in CM3
Range from the cheapest single storey extension £35600 (1st Fix Home Improvements based in CM9) to the dearest single storey extension £50000 (Mr. based in CM1).
Comparing extension builders estimates for fitting a downstairs toilet 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 to build a single storey extension in CM3 by posting a job with HaMuch and we will send it to extension builders in CM3.
Estimates for common extension builder jobs in CM3;
| Job | Estimate |
| Underpinning a house | £17233 |
| Build a two storey extension | £87599 |
| Build a timber frame extension | £25733 |
| Install a swimming pool | £80733 |
| Cost to build a single storey extension | £44656 |
| Cost to build a side return extension | £34494 |
| Install an RSJ | £1933 |
| Build an outbuilding | £9733 |
| Build a mansard loft conversion | £51733 |
| Cost of a loft conversion | £31245 |
| Build a kitchen extension | £41733 |
| Build a hip to gable loft conversion | £41733 |
| Build a granny annexe | £86733 |
| Build a garden office | £9733 |
| Convert a garage | £15733 |
| Build a new garage | £18233 |
| Build a flat roof extension | £21733 |
| Build a dormer loft conversion | £41733 |
| Lay a concrete foundation | £5983 |
| Convert a bungalow loft | £28733 |
| Basement conversion cost | £34494 |