Risk analysis of escape time in buildings of Hong Kong

Fire safety of some buildings is examined from the perspective of the risk of evacuees, who would be unable to escape from an unprotected space through the designated exits in the period of time allowed. This paper, taking account of exit design, occupant load and its variations using the door carrying capacity approach, presents a simple method to determine the probable risk to evacuees in buildings of Hong Kong. The probable risk of evacuees in example residential, institutional and office buildings of Hong Kong was evaluated for certain exit dimensions with the door carrying capacity, with considerations of the uncertainties of the probable occupant loads and the specific flow rates at the exit. The results show that the building occupant load, occupant-load ratio, total exit width and specific flow rate at the exit significantly affect the risk to evacuees. The result would be useful in the risk assessment for safe egress design of buildings.