In an anarchist society I don't think there is any place for holding property you are not actually using yourself. Owning more property than your immediate needs for housing yourself and those things you have rightfully acquired through VOLUNTARY exchanges or directly through your labor, or land that you put work into for crops, or beautification ect. is merely maintaining the means to extort others for a portion of the product of their labor, giving them no lasting return. That said, if you build a home and sell it that is perfectly reasonable, if we find ourselves in an anarchist society and you work out terms to sell rental properties to recover value on what you have paid in..fine. But with anarchy will also come the fall of the fiat currency banking system, so anything "owed" to the banks on money they got from thin air will be void, and the stake you have in any property will be only the portion you have already paid off on mortgages... As for the rest of the value of the house, that is no more rightfully yours than it is anyone elses so recoup your actual investment and move on. The other side of this is yes every person has the right to control the property on which his house, and possessions sit, along with any land they put their labor into improving, working, and maintaining, so long as they or their benefactors continue the work that gave them the right to claim it to begin with,so long as it is not abandoned, or the work does not cease for an excessive period of time, .....and the right to defend it from agressors, for any theft of the product of one's labors is the theft of their time and bodily efforts is slavery.