Understanding Factors Influencing Overheating: The UK’s First Large-Scale Domestic Passivhaus Retrofit

Abstract

Overheating in dwellings is a major consideration affecting buildings in both temperate climates like the UK, as well as in warmer climates. At the same time, it is recognised that the impacts of global warming and climate change are affecting weather patterns in the UK resulting in many changes, including long periods of hot weather in the summer and warmer wetter winters (Lowe et al., UKCP 18 science overview report. Met Office, November 2018 (updated March 2019). https://www.metoffice.gov.uk/pub/data/weather/uk/ukcp18/science-reports/UKCP18-Overview-report.pdf, 2018). In order to reduce global CO2 emissions, fabric improvements are being made to buildings to make them more energy efficient. To achieve these improvements the thermal insulation and airtightness of the building is often improved. The combination of these factors not only serves to retain heat energy during winter heating periods, but it can also result in excessive rises in internal temperatures during the summer, resulting in overheating. This can result in the building occupants’ experiencing discomfort and they may even be exposed to temperatures that pose serious health risks for the most vulnerable in society. In order to provide a safe and healthy environment for occupants, we must provide energy-efficient dwellings that consider not only current but also future climate scenarios. The paper presents the initial findings of a study investigating the risk of overheating in the UK’s first large-scale Passivhaus retrofit.