[onetwo_threefour]

I am not aware of any rules stating that you can't own a single property in a corporation. It is possible that you may obtain some beneficial tax treatment if you do own many properties and become a 'rental corporation' as you called it but I am not aware of anything in that regard. Legally speaking you can hold whatever assets you want in the company and there is some potential protection from liability by leaving it in the company's name. So unless there was some valid reason to realize a gain or loss for the company I would say leave the ownership as it is.