To prevent people from unintentionally falling from one level to another.
Buildings and their facilities shall be constructed to reduce the likelihood of unintentional falls.
A barrier shall be provided where people could fall 30 inches (762 mm) or more from an opening in the external envelope or floor of a building or its facilities.
Roofs with permanent access shall have barriers provided.
Barriers shall be constructed and installed appropriate to the hazard.
When barriers have openings, the openings shall be of an appropriate size and configuration to keep people from falling through based upon the anticipated age of the occupants.