Fire Safety Science Digital Archive

Usually, it is required by building codes that two or more escape routes be available from every point in a building for the purpose of assuring at least one available egress route should the other happen to be blocked by fire. The limitation of common path length and the requirement of two or more stairways for buildings exceeding certain size are typical examples of such requirements. Despite their vital influence on building design, lucid explanation has not been given to the adequacy of the provisions. In this paper, the meaning of the code requirements on common path length and number of stairways is discussed, and the criterion that may be used as an alternative to such prescribed standards is derived based on the consideration of the expected number of occupants unable to escape.