Houses on Inactive Accounts
If your account becomes inactive for any reason, any house you own on that account will be set to "Condemned" status. An inactive account is one that has been cancelled or suspended for more than [highlight]90 days.[/highlight] If your account remains inactive for more than 90 days, your house will begin a decay period of about 5 days. If you reactivate your account within the initial [highlight]90-day grace period[/highlight] or before your house finishes its 5-day decay period, then it will return to its original status of "Primary."
So, in a nutshell, [highlight]you have 90 days to reactivate your account,[/highlight] or your house will vanish. But don't wait until the last moment!
Grandfathered houses follow the same rules, with one exception. You must reactive your account within the 90-day grace period in order to keep the Grandfathered status of your houses. If, instead, you reactive your account after that 90-day period, when the houses have started the 5-day decay cycle, then only the house that was most recently placed will be set to "Primary." All others will become condemned.
Note: Once you reactivate your game account, it can take up to 24 hours for the houses on your account to reflect this change. In other words, if your house has become condemned because your account was inactive, it can take up to 24 hours after your account becomes reactivated for your house to become un-condemned.
Quoted from The Herald