This report by the Zero Carbon Hub presents preliminary findings from a two-year project intended to investigate the extent to which the housing sector is gearing up address overheating risk and assess what changes to business processes and government frameworks needed to increase the resilience of the housing stock to extreme heat.
- “Double-glazed windows with a low-e coating prevent heat from escaping. Houses with unshaded west-facing glass will suffer from higher levels of solar gain in the warmer part of the day.”
- “Looking forward, whilst predicting the future incidence of overheating is not possible, an examination of drivers of change, climate change studies and modelling exercises all point towards the conclusion that overheating will become more common in the housing stock in England and Wales.”
- “Overheating can damage residents’ health and wellbeing, increase social care costs, reduces economic activity, increase NHS costs and lower quality of life.”
It is clear that overheating is happening – potentially in up to 20% of the housing stock in England. In August 2003 England experienced unusually high temperatures which are becoming more frequent and intense due to climate change. There were over 2,000 deaths during the ten day heatwave in 2003, the worst affected were people over the age of 75 years.
It is extremely difficult to quantify the levels of overheating in homes over the long term, but if current trends continue, it is highly likely that overheating will become more common place. Overheating impacts include:
- Heat-related morbidity and mortality are projected to rise, while heat-related deaths are expected to triple
- Healthcare costs are estimated to rise significantly, representing a four-fold in mortality-related costs and a doubling in morbidity-related costs
- Economic losses are expected as a result of work-days lost, accidents and reduced productivity due to sleep deprivation (or when working at home)
- The energy efficiency and fuel poverty agendas could suffer set-backs if the sector begins to use more energy to cool homes as standard practice
- Customer relations damage and reputational harm within commercial settings
The cause of overheating varies from building to building and is dependent on location, type of property, fabric characteristics including insulation of the building envelope and positioning of glazing, orientation and exposure to solar gain, occupants and their behaviour and ventilation strategies which can be impacted by external noise and security issues.
In many cases shading can be used as an effective measure to reduce the potential for overheating and is recommended in the “Cooling Hierarchy” which is planning guidance for the Greater London Authority.
The report concluded that overheating cannot yet be considered to be a managed risk for much of the sector. There are gaps and uncertainties in current frameworks which mean inherently risky designs and buildings can be approved. Secondly, despite evidence gaps, there is enough information and evidence about the causes, extent of, and solutions to overheating in homes to warrant taking careful yet concerted action to tackle the issue.
Download the report here: ZCH Overheating In Homes-The Big Picture
For all the resources from the Zero Carbon Hub on overheating in homes here.