If they have served notice, you will be able to claim liquidated damages. The amount you can claim will be specified in the contract and will be in the order of £50 per day. However, the builders will only serve notice once they are absolutely certain that they won't have to pay any damages. They do this by serving notice just a couple of weeks before the property is finished.

If they have not served notice, it is not possible to claim compensation. This is despite the fact that the sales staff will have probably given you an unrealistic moving date to close the deal resulting in significant inconvenience and expense. The best way to mitigate this risk is to buy a stock home or to use a part-exchange scheme if one is available.