Every room shall have at least one window which can be easily opened or such other device as will adequately ventilate the room. The total openable window area in every room shall be equal to at least forty-five (45) percent of the minimum window area size required in Section 15.36.350 except that no openable window shall be required in bathrooms or water closet compartments equipped with an approved ventilation system. (Prior code § 17-1-45)