I think adding instanced rural housing might work. Each instance would be a private piece of land with only 1 housing plot on it by itself surrounded by wilderness, rather than other houses. I don't think it would take much more effort than the current apartment system, and it would also cause less server load than the wards, since each house would only need to be loaded when a player is present, as opposed to the wards which have to be loaded 24/7. This system, like the apartments, could be implemented on top of the currently existing ward system, which would continue to work as before.