An automatic sprinkler system shall be installed throughout every above-grade story of buildings below a height of 100 feet (30 480 mm), other than the first story or ground floor, on which access is not provided directly from the outdoors by at least one window or readily identifiable access panel within each 50 feet (15 240 mm) or fraction thereof of horizontal length of every wall that fronts on a street or frontage space required pursuant to Section 501.3.1.
Such windows shall be openable from the inside or breakable from both the inside and the outside, and shall have a size when open of at least 24 inches by 36 inches (610 mm by 914 mm). Such panels shall be openable from both the inside and outside and shall have a height when open of 48 inches (1219 mm) and a width of at least 32 inches (813 mm). The sill of the window or panel shall not be higher than 36 inches (914 mm) above the inside floor. Where not all of the windows are openable or breakable, the windows intended to satisfy the requirements of this section shall be readily identifiable.