Design fire in performance-based fire safety design for green and sustainable buildings

Construction industry in the Far East is developing rapidly with many new architectural features for achieving green and sustainable designs. Fire safety has drawn public attention consequent to the serious accidental fire occurred at the Garley Building in 1996. Therefore, fire safety provisions have to be assessed vigorously. There might be difficulties for some of these new architectural features to comply with the current prescriptive fire safety codes. The environmental friendly design might even be in conflict with the fire safety requirements. Special design considerations are required individually for such buildings. Performance-based design known as the "fire engineering approach FEA" is accepted in Hong Kong since 1998. Basically, this applies to passive protection constructions in demonstrating that the building elements which did not satisfy the code requirements are of equal safety to what specified. The problem is more serious especially for glass construction. Hazard assessment is required and the heat release rate of the design fire is a key issue. All the fire safety provisions were determined based on that. The fire safety strategy for bigger organizations such as railway systems will be worked out based on the estimated heat release rate. As the responsibility lies with the Authority, not the fire engineer concerned, there were lots of arguments on the design fire. This point will also be discussed in this paper. On the estimation of the probable heat release rate, empirical equations on ceiling jet for assessing the thermal response of sprinkler heads were commonly applied. Whether this approach is good will also be discussed with support from full-scale burning tests on measuring the heat release rates with sprinkler. It should be pointed out that operating the suppression system might not necessarily keep the heat release rate of the fire at the estimated value.