Exploring the role of building codes in protecting occupants from overheating—A Canadian perspective

• Overheating metrics and thresholds in building codes need to be linked to health. • Current recommendations are limited by existing knowledge, tools, and practices. • Establishing national guidance on using future climate data for design is critical. • Passive measures are essential to lessen the resource burdens of active cooling. • Flexible compliance paths address varied project resources and risk thresholds. Extreme heat events are becoming more frequent and more severe as climate change continues to progress. This poses significant risks to human health and safety. These impacts highlight the urgent need to address overheating resilience in residential buildings, where heat-related injuries notably occur. Historically, building codes have been essential in protecting occupants against environmental hazards, but integrating provisions to reduce overheating remains a global challenge. Overcoming stakeholder disagreements, changing entrenched design practices, and developing practical assessment methodologies are key barriers to progress. By compiling the most recent findings and research on overheating resilience, with an emphasis on residential buildings, this article seeks to advance the discourse about incorporating overheating protection in national building codes. This paper examines physiological thresholds for overheating, practical metrics for assessment, and strategies for aligning building code priorities with health and equity considerations. The complexities of balancing energy efficiency with overheating protection (particularly for heating-dominated climates) are also covered. Drawing on these insights, a framework of priority actions is proposed to guide the development of national building codes, ensuring they evolve to meet the challenges of a warming climate. This article discusses possible approaches to include overheating resilience in building codes for residential buildings through a Canadian case study, using the National Building Code of Canada. The findings are intended to serve as a foundational reference for jurisdictions worldwide seeking to enhance overheating protections in their regulatory frameworks.