ABSTRACT
Provisions concerning requirements of two or more means of escape in the building codes of several countries. The objective of the requirement of two or more exits for rooms is designed to assure alternative exit/exits even when an exit happens to be blocked by fire. The scenario that is assumed in the requirement of two or more exits for rooms is considered to be the former, i.e., an inside fire adjacent to a doorway. The requirement of two or more exits from a room has been discussed from the viewpoint of the expected number of occupants unable to escape, and a criterion for the required number of exits is proposed as an alternative to the existing provisions. The scenario that is assumed in the requirement of two or more exits for rooms is considered to be the former, i.e., an inside fire adjacent to a doorway.
