this also rules out every floor that has an odd number of rooms

On the fifth highest floor,to fulfill our starting conditions,we'd need four rooms with three neighbors each,plus the control panel room with one neighbor,which makes 13 total neighbors.Since that's an odd number,it's not possible,and, in fact, this also rules out every floor that has an odd number of rooms.So let's go one more floor down.When we draw out the rooms,low and behold, we can find an arrangement that works like this.