Effect of electric vehicle fire hazard on the fire design of contemporary timber-framed house garage in Australia

Electric vehicle (EV) adoption is rapidly increasing in Australia as well as around the world, as it is supporting national decarbonisation goals. Despite this, the battery used in EVs poses a severe fire risk when subjected to physical damage. The garage of the timber-framed house is highly prone to suffering from this unique and severe fire. As the garage’s walls were designed based on the deemed-to-satisfy criteria specified by the fire resistance level (FRL), which follows the standard fire curve. However, an EV fire is non-linear and initiated by a violent thermal runaway, making it unpredictable, and these conditions were not accounted for in the traditional fire safety design approaches for timber-framed walls. This study assesses the FRL of timber-framed walls subjected to EV fires through the validated fire dynamic simulation. A timber-framed wall panel and the walls attached to the representative house garage were subjected to twelve different EV fires. Results show that the FRL of the timber-framed wall attached to the garage declines abruptly within 15 min in both structural adequacy and integrity, leading to early structural compromise and increased fire spread, ultimately resulting in both structural and thermal insulation failure under EV fires. These findings indicate that the fire resilience of the current timber-framed house design is inadequate in the event of EV fires, highlighting the need for improvements in design and construction regulations.