SR238 Residential design fire scenario selection - using New Zealand fire incidents (2018)

Sets of design fire scenarios are required as one of the inputs for the probabilistic model currently being developed. Results and experience from analysis of New Zealand fire incident statistics were used in the identification of the most important design fire scenarios for residential occupancies in terms of life safety for apartments and all residential types of buildings.

A normalised weighting of design fire scenarios was developed that incorporates:

• the magnitude of the incidents (in terms of total numbers of incidents and casualties)
• the severity of the incidents (in terms of casualties per incident)
• a measure of the confidence in the available statistics (in terms of the spread of data compared to assumed normal distributions for each of the scenarios considered).

Example distributions of fire design scenarios based on a normalised weighted combination of the importance values, based on percentages and ratios, for apartment fire statistics is in a form that can be used as an input for the probabilistic model currently in development as part of the larger project that this research was performed within.

The summary of the analysis presented here focuses on life safety of occupants. A similar approach may be used focusing on protection of property if, for example, extent of flame damage statistics were used instead of casualties. The approach presented here could also be applied to commercial occupancies.