Starting with the 3.1 patch drop, people who own houses in game must visit their homes once every 45 days or they'll lose their property.
http://na.finalfantasyxiv.com/lodestone/topics/detail/424658bcd52a5737194a4088eb3e7ccabefa9954#_ga=1.140046259.1241946526.1444836845
Personally, I like this. There's no reason for people to own homes if they're only going to sub during the month after patches. Also, looks like people who lose their homes will get back 80 percent of what they paid for their property along with their furnishings (retrievable from a new NPC for 35 days).
Will be interesting to see how this shakes out. If I were a player who frequently unsubbed, I'd be tempted to just sell my house now rather than worry about logging in more often.