Thanks for your reply.
To be honest I was expecting a more detailed response regarding my Buy to Let property, I have already visied the HRMC website however I find it does not really answer my question. My original question is as follows-
'Also, we are currently buying a Buy to Let property which I will let out to tenants. When we have sold our current residential property could we then change this Buy to Let into a residential mortgage? We would then aim to move back from Australia at some point and live in this property in order to avoid paying capital gains tax when we eventually sell it. Is this something we can do? and if yes how long do we have to live in this property to avoid paying CGT?'
Look forward to hearing from you.