That's definitely part of it. But, also because it's not part of the building code, they can just lie. So, even if you go look at a luxury apartment building, they might tell you that it's high quality and you can't hear the neighbours at all. Maybe if you get a chance to talk to someone who lives there they can tell you the truth. But, in my experience a lot of real estate agents / rental agents / landlords and the like lie.