1462.11  LIGHT AND VENTILATION REQUIREMENTS.
   (a)   General Requirements.  The owner of a structure shall provide and maintain light and ventilation and space conditions in compliance with these requirements.  A person shall not occupy as owner-occupant, or let to another for occupancy or use, any premises which do not comply with the following requirements of this section.
      (1)   All structures shall be provided access to public property.  Such means of access shall be maintained unobstructed.
      (2)   An open space, when used for the origin of light and ventilation, shall be maintained and unobstructed.
      (3)   In place of the means for natural light and ventilation herein prescribed, alternative arrangements of windows, louvers or other methods and devices that will provide the equivalent minimum performance requirements shall be permitted when such other arrangements are in compliance with this Building and Housing Code.
   (b)   Light.  All spaces or rooms shall be provided with sufficient light so as not to endanger health and safety.
      (1)   Habitable spaces.  Every habitable space shall have at least one window of approved size facing directly to the outdoors or to a court.  The minimum total window area, measured between stops, for every habitable space, shall be eight percent of the floor area of such room, except in kitchens when artificial light is provided in accordance with the provisions of this Building and Housing Code. 
         Whenever walls or other portions of a structure face a window of any room, and such obstructions are located less than three feet (914 mm) from the window and extend to a level above that of the ceiling of the room, such a window shall not be deemed to face directly to the outdoors, nor to a court, and shall not be included as contributing to the required minimum total window area for the room.
      (2)   Common halls and stairways.  Every common hall and stairway shall be adequately lighted at all times with an illumination of at least a sixty-watt standard incandescent light bulb or equivalent thereof for each 200 square feet (18.60 m2) of floor area, provided that the spacing between lights shall not be greater than thirty feet (9144 mm).  Every exterior stairway shall be illuminated with a minimum of one foot-candle (10.76 lux) at the floor, landings and treads.
      (3)   Other spaces.  All other spaces shall be provided with natural or artificial light of sufficient intensity and so distributed as to permit the maintenance of sanitary conditions and the safe use of the space and the appliances, equipment and fixtures.
   (c)   Ventilation.  All spaces or rooms shall be provided sufficient natural or mechanical ventilation so as not to endanger health and safety.  Where mechanical ventilation is provided in lieu of the natural ventilation, such mechanical ventilating systems shall be maintained in operation during the occupancy of any structure or portion thereof.  When part of the air provided by a mechanical ventilation system is recirculated, the portion or volume of air recirculated shall not be recirculated to a different residential space from which it is withdrawn.
      (1)   Habitable spaces.  Every habitable space 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 percent of the minimum window area size required in paragraph (b)(1) hereof.
      (2)   Toilet rooms.  Every bathroom and water closet compartment shall comply with the light and ventilation requirements for habitable spaces as required by paragraph (b)(1) hereof, except that a window shall not be required in bathrooms or water closet compartments equipped with an approved mechanical ventilation system.  Air exhausted by a mechanical ventilation system from rooms containing a bathtub or shower within a dwelling unit shall be exhausted to the exterior and shall not be recirculated to any habitable space, including the space from which it is withdrawn.  Air exhausted by a mechanical ventilation system from all other bathroom or water closet compartments shall be exhausted to the exterior without recirculation to any space, or not more than eighty-five percent of the exhaust air shall be recirculated where the system is provided with effective absorption and filtering equipment complying with this Building and Housing Code.
      (3)   Clothes dryer exhaust.  Clothes dryer venting systems shall be independent of all other systems and shall be vented in accordance with the manufacturer's recommendations.  Gas dryers shall be vented to the exterior.
(Ord. 2285.  Passed 1-14-91.)