On some of our small 2 story government buildings built many years ago, we tend to have stairs that resemble a stairwell but there are no doors to the stairs on the 1st floor nor on the 2nd floor. At times there may be a door built later on one of the floors to control access- no for fire/smoke separation. At times it's a straight run of stairs from 1st to 2nd floor and at other times, the stairs are in a tight U shape. There is no open air space to look down or up. Is this a BS(1st floor) and void(2nd floor) scenario or does one stay with Vertical penetration?