I once worked in an office that was split level. The support staff (all women) were on the upper level, and the sales staff (all men) were on the lower level. There was one restroom for the women, and it was located on the lower level, and the door opened to the sales floor where all the men's desks were. This was a single room restroom. You open the door and there's the toilet and sink. No stalls.
It was so uncomfortable when any of us had to use the restroom. There was absolutely NO privacy whatsoever. They pretty much knew everything that went on in there, and we heard them joking about it. One poor girl had to do a #2 very badly, and was in there for quite a while. Even though she used the spray and had the fan on, when she opened the door, well ... you know.
It was horrible. Most of us would rather walk a few blocks to the building down the street and use their restrooms than use the one in that office.