Approved Document Part O, forming part the 2021 Building Regulations, has been effective since June 2022. It covers overheating in new residential properties in England and Wales including private dwellings such as houses and flats, institutional buildings such as care homes and other accommodation including student halls of residence.
Overheating of buildings has become a significant issue in the construction industry for housebuilders and the self-builder. This is the result of a number of contributory factors including the air tightness of new dwellings coupled with insufficient ventilation. Another contributing factor has been the more extensive use of glazing within new builds. Climate change, and the number of summer days when unprecedented high temperatures have been recorded, also has an impact and is a trend which looks set to continue.