This research investigated the heat transfer in safe rooms exposed to bushfires and their bushfire resistance using full-scale laboratory and out-door experimental studies of external wall systems and a safe room, and associated advanced numerical studies. It has advanced the knowledge and understanding of the heat transfer and the performance of the critical external building envelope and the safe rooms with different configurations exposed to bushfire flame conditions. Suitable solutions and methodologies have been proposed, addressing various complexities and challenges, which can be used in any bushfire-prone country like Australia. This will improve life safety and community resilience during bushfires.