Resilient design in extreme climates

Overheating has become a major factor in building energy consumption, and thermal discomfort and a health risk for vulnerable populations in a heating world. As a result of the popularization of mechanical systems, energy consumption often peaks during hot periods. A vicious loop emerges as CO₂ and greenhouse gas emissions generated to mitigate the consequences of global warming will further contribute to exacerbate the trend. However, there is no broadly accepted single method for measuring overheating in naturally ventilated buildings. Most of the published methods rely on a simple count of hours above a theoretical comfort limit, regardless of the intensity and extent. This deterministic approach makes difficult the introduction of passive strategies as it falls short of accounting for adaptive measures. This chapter proposes a novel 5-step overheating assessment method (5-SOAM) for naturally ventilated buildings. The method provides a more flexible framework to assess the actual suitability of indoor spaces for human habitation through an analysis of the overheating frequency and intensity. The approach is based on the tabulation of overheating occurrence in five bands, reflecting the thermal difference from the upper comfort thresholds. The output provides a sensitive index that determines the scale of overheating risks in buildings.