Risk mitigation for combustible cladding in residential buildings

Combustible cladding on the building façade changes the compartmentation design, increasing risk to buildings by providing additional fuel loads and pathways to spread fire between compartments. However, the level of threat is not the same for all buildings that have Combustible External Cladding as part of their façade structure. The Protocols for Mitigating Cladding Risk (PMCR) is an approach developed by Cladding Safety Victoria (CSV) on behalf of the Victorian Government to consistently and systematically address the risk posed by the presence of combustible cladding on Class 2 and Class 3 buildings (being multi-storey residential structures) in line with the Minister’s Guideline 15 (Department of Transport and Planning, 2023). This paper presents the development of PMCR following the Threat-Barrier analysis with a set of 15 related risk mitigation interventions that may be applied which fall into five categories: (1) Interventions to suppress fires; (2) Interventions to reduce cladding fuel; (3) Interventions to address energy ignitions; (4) Interventions to detect fire and alert people, and (5) Intervention to assist safe egress from a building. The risk quantification has been successfully developed by adopting Bayesian Network and other advanced computing techniques which generates the understandings into the influence of different interventions on the cladding risk premium and contributes to the development of a proportionate mitigation strategy for combustible claddings.