430 ILCS 180/10

All existing buildings, new construction, new roofs, roof replacements, and renovation projects that increase the area of a home or business by more than 50% are subject to the following requirements: (1) The edges of a low-sloped roof that adjoin a shaft or a court that is enclosed on all sides shall be provided with a parapet, extended masonry, or guard, or any combination thereof that meets the requirements of Section 1015 of the International Building Code. (2) All skylights and other openings located in the plane of a low-sloped roof that are not otherwise required to remain open and unobstructed by law shall be either: (A) glazed with wired glass, plain glass, glass block, or polycarbonate plastic that is designed and constructed to withstand a minimum dynamic load test of no less than 400 pounds; or (B) provided with a parapet, extended masonry, or guard, or any combination thereof, that meets the requirements of Section 1015 of the International Building Code.