A. Natural Light and Ventilation. All guest rooms, dormitories and habitable rooms within a dwelling unit shall be provided with natural light by means of exterior glazed openings with an area not less than one twentieth of the floor area of such rooms with a minimum of 5 square feet. All bathrooms, water closet compartments, laundry rooms and similar rooms shall be provided with natural ventilation by means of openable exterior openings with an area not less than one-twentieth of the floor area of such rooms with a minimum of 1 1/2 square feet. All guest rooms, dormitories and habitable rooms within a dwelling unit shall be provided with natural ventilation by means of openable exterior openings with an area of not less than one-twentieth of the floor area of such rooms with a minimum of 5 square feet.
B. Origin of Light and Ventilation. Required exterior openings for natural light and ventilation shall open directly onto a street or public alley or a yard or court located on the same lot as the building.
EXCEPTION: Required windows may open into a roofed porch where the porch:
1. Abuts a street, yard, or court; and
2. Has a ceiling height of not less than 7 feet; and
3. Has the longer side at least 65 percent open and unobstructed.
A required window in a service room may open into a vent shaft which is open and unobstructed to the sky and not less than 4 feet in least dimension. No vent shaft shall extend through more than two stories.
For the purpose of determining light and ventilation requirements, any room may be considered as a portion of an adjoining room when one half of the area of the common wall is open and unobstructed and provides an opening of not less than one tenth of the floor area of the interior room or 25 square feet, whichever is greater.
C. Mechanical Ventilation. In lieu of openable windows for natural ventilation, a mechanical ventilation system may be provided. Such system shall be capable of providing two air changes per hour in all guest rooms, dormitories, habitable rooms, and in public corridors. One-fifth of the air supply shall be taken from the outside. In bathrooms, water closet compartments, laundry rooms, and similar rooms, a mechanical ventilation system connected directly to the outside or into attic space properly ventilated in compliance with the current building code capable of providing five air changes per hour, shall be provided.
D. Hallways. All public hallways, stairs and other exitways shall be adequately lighted at all times in accordance with the Building Code.
(Amended by Ordinance No. 9044, effective 6-7-2006)