First, the house does NOT transfer over with you. It doesn't matter which ever it may be a personal or free company house. If you are the leader of a free company and other members decide NOT to transfer with you, one of those member will be assign leader of the free company and the free company house will remain with them in the server that you transferred out of. This is my understanding and from what I have read in regard to this. You will need to buy a new house at the server that you decided to transfer to. So it be in your best interest if you decide to transfer is to FIRST, create a character on the server you want to transfer and check if plots are available, if any. Also if you're inclined to transfer to a legacy server, don't bother transferring if you're in the idea of getting a house.
I didn't find the right solution from the Internet.