§ 215. Interior water-closets and bathrooms. 1. Except as otherwise provided in this section, water-closets, bath and shower rooms may be ventilated by windows or mechanically ventilated as prescribed in section one hundred seventy-one.
2. In transiently occupied dwellings there shall be on each story at least two water-closet compartments for the first twenty living rooms or fraction thereof and at least one additional water-closet compartment for each additional fifteen living rooms or fraction thereof.
a. The water-closet compartments on each story shall be accessible from every such living room on the story. Such water-closet compartments may be placed in one or more general toilet rooms.
b. Every water-closet compartment of a general toilet containing water-closet compartments permitted under this subdivision shall have a window opening to the outer air of the dimensions, kind and location required in a living room of the same area by section one hundred three, or be provided with a system of mechanical ventilation as prescribed in subdivision six of section one hundred seventy-one.