A new methodology of evaluation of overheating in buildings.

• Developed a general methodology to define and characterise overheating events and evaluate the risk to reduced comfort and undesirable health effects of building occupants exposed to extreme heat events. • Developed criteria to declare overheating based on heat-related health outcomes related to limits for body dehydration and core temperature of healthy average-age and older people. • Applied the methodology to a case study of a residential building with typical local construction in cold climates and compared the results with those from other existing methods. • The proposed methodology sets the groundwork for establishing a benchmark model from which different overheating metrics can be compared. Overheating in built environments during climate extreme heat events is a major concern to human health, particularly for people vulnerable to prolonged exposure to heat and humidity. However, currently available methods for assessing the risk of overheating lack robust procedures to evaluate the effects of overheating on the comfort and health of vulnerable occupants residing in the various different dwellings. This paper developed a general methodology to define and characterise overheating events and evaluate the risk to reduced comfort and undesirable health effects of building occupants exposed to extreme heat events. Criteria to declare overheating were developed based on heat-related health outcomes related to limits for body dehydration and core temperature of healthy average-age and older adults. The methodology was then applied to a case study of a residential building with typical local construction practice for cold climates and compared with existing methods for assessing risk from exposure to extreme heat events. The results showed that all the methods predicted that highly insulated and airtight buildings are more prone to overheating than older buildings that are less well insulated and airtight. However, only the proposed methodology described in this paper predicted that natural ventilation through opening windows significantly reduced the overheating risk to below the threshold value. Furthermore, multi criteria methods might be difficult to apply in practice in that it is not guaranteed to violate all the criteria to declare a building space is not overheated. The proposed methodology sets the groundwork for establishing a benchmark model from which different overheating metrics can be compared. [ABSTRACT FROM AUTHOR]