§ 151.365 HABITABLE SPACES.
   (A)   General. Every habitable space shall have at least one window of approved size facing directly to the outdoors or to a court. The minimum total glazed area for every habitable space shall be 8% of the floor area of such room. Wherever 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 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.
   (B)   Exception. 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% of the floor area of the interior room or space, but not less than 25 square feet (2.33 m2). The exterior glazing area shall be based on the total floor area being served.
(2009 Code, § 29-4-5)