perhaps a small fan in the bathroom to use for ventilation

The apartment is in a new building in New York City...70 units. I need to find out from people with non-studios if they have the same situation. The bathroom is in the front of the unit, at the opposite end from the window wall, so using the window (which also opens only to a limited height) does not really help.

We had an experience with such a bathroom in Cape Cod. I wouldn't wish that to my enemies:) I would ask to see if this is legal..moisture and no ventilation brings trouble

I cannot imagine a new build could have such a situation. Did someone pay off the inspector? This should be a valid reason to break a lease.

The code that is being guessed about here is under this section, and does not apply to apartment buildings over 3 stories.

That's right, Fred....it's seven stories.....

are you certain it doesnt have a constant fan? just because there isnt a switch doesnt necessarily mean there isnt negative air flow.