I can't say for certain, but I think most regulations about windows are about having an escape in case of disaster.
Specifically, there was house we were looking at, and one of the previous owners covered up the back porch.
However, one of the bedrooms used to overlook that back porch, and had a window on that wall.
They were not allowed to remove that window because "bedrooms have windows", even though the window was an interior window.
Similarly, we considered replacing our bedroom window with a bay window, but the code would not allow it because the windows were too small to allow egress.
I completely forgot about the fire thing, and that only strengthens my argument/stance. The Triangle fire was a terrible tragedy in American history during which a lot of women died not even because of lack of windows, but because doors and windows were barred. Now imagine how many people would be at risk if they didn't even have windows in the first place.
Specifically, there was house we were looking at, and one of the previous owners covered up the back porch.
However, one of the bedrooms used to overlook that back porch, and had a window on that wall.
They were not allowed to remove that window because "bedrooms have windows", even though the window was an interior window.
Similarly, we considered replacing our bedroom window with a bay window, but the code would not allow it because the windows were too small to allow egress.