Lighting standards. In the application of the provisions of this chapter, the standard of natural light, unless otherwise specifically required by the building provisions of this Code for special occupancies and uses (described in Section 13-172-060), shall be based on 250 footcandles (2,691 lux) of illumination on the vertical plane adjacent to the exterior of the light- transmitting device in the enclosure wall and shall be adequate to provide an average illumination of at least 6 footcandles (64.58 lux) over the area of the room at a height of 30 inches (762 mm) above the floor level.
Minimum glazing area. Every room or space intended for human occupancy shall have an exterior glazing area of not less than 8 percent of the floor area. Natural light shall be provided by glazing areas that open onto courts, yards or public ways which comply with the requirements of Section 13-172-130, or by other approved means.
Borrowed light for remote rooms. Where natural light for rooms or spaces without exterior glazing areas is provided through an adjoining room, the unobstructed opening to the adjoining room shall be at least 8 percent of the floor area of the interior room or space, but not less than 25 square feet (2.33m2). The plane of the opening through which light is borrowed for a remote room without windows shall be parallel to the window wall. The exterior glazing area shall be based on the total floor area being served.
(Added Coun. J. 4-29-98, p. 66679, § 1)