Performance Based Fire Engineering to Mitigate Non-Compliance in Exit Provisions

Addition and Alteration works to aging buildings have become common place in land scarce Singapore. For a recent retail development in the Central Business District, the developers choose to convert the basement parking facility in the existing building to a retail facility with a large F&B component. However, the exit provisions were insufficient to serve the larger occupant load demanded by F&B. This paper briefly describes the Performance Based approach to taken to mitigate the non-compliance. Several strategies were implemented as part of the Performance Based approach to ensure that the inadequate exit provisions will not compromise tenable conditions needed for evacuation. Appropriate Design Fire scenarios were conceptualized and associated Available Safe Egress Times (ASET) were evaluated using FDS. Appropriate pre-movement timings were derived from prior evacuation studies and the movement times were evaluated using evacuation modeling. By demonstrating to the AHJ that the Required Safe Egress Times (RSET) was less than the ASET, the performance based design of the development was accepted.