Re: Apartment Building
@blindude Normally, anything not marked with either a public or NPC hidden room marker is considered part of the active family's apartment. That's how some builders get into trouble—they build a game room or something downstairs without marking it as public, and their bills skyrocket. But I don't know how the game would treat balconies specifically, since they're technically outside.
You could experiment a bit more with the markers, though. Any time you start a new save and move a famiy in, they should get their first bill the next day just after 8 am. If you save right before, you could fiddle with the building and see what happens to the bills. If adding a massive balcony to the NPC apartment doesn't change the amount due, you'll know it's public.
I also wonder if you can't build properly (that is, without cheats) in public areas once your sims have moved in. I'm not sure about this, but if not, that would be an even easier way to figure out what the game considers public.