exit proceedure

Tenancy Types and Management

I am a novice landlord and would welcome some advice. I have a tennant who's six month tennancy agreement comes to an end on the 23 September. He has been a good tennant and I have no complaints. He has decided to move in with his daughter and son in law to a bigger house and I accept that there is not enough room for them all at my property. However, the house he is due to rent is being refurbished and he cannot give me a precise date for moving out, as he does not know when it will be ready. I have already found a new tennant but at present am unable to let her know a move in date. Any advice on what to do or where i stand once the tennancy rolls over would be most greatful.