Quote Originally Posted by Jojoya View Post
So then what happens when a new expansion gets released? Everyone's house demos and it becomes a free for all among those who reach the new level cap first?
Yes, this is the rational conclusion to come to. lol

I assume it would work like other things that you need to reach max to unlock. For example, the new requirements for mentor increase every expansion. The progress you made during one expansion isn't going to be wiped and you wouldn't lose your house. If you wanted to buy another house though you would need to meet the new requirements.