What counts as a walled zone in Towns?
I have heard that a zone which is completely surrounded by walls (with doors and windows permitted) results in more efficient production.
Does this require that the zone have a room to itself (i.e. all floor tiles within the wall are that zone) or merely that the zone is within a room (so that multiple zones can share one room/building)?
Or is it simply that zones are enhanced by nearby walls, without regard to whether they are contiguous?
Additionally, does it matter whether the walls are more than 1 block high (i.e. cannot be walked over), or whether there is a roof?
I believe it just needs to be inside, that is, under a roof. This is actually what led to me changing from building below ground to building above ground.