Can addressing thermal bridges and lowering psi values help to improve the health of building occupants?
Of all the actions needed to help the UK reach its target of net zero carbon, home energy efficiency measures would also make the greatest contribution to improving the population’s health. That is one of the findings of a new study by the London School of Hygiene & Tropical Medicine (LSHTM), summarised by assistant professor Dr James Milner writing for Carbon Brief.
Home energy efficiency includes increasing insulation levels to lower U-values. But improving the performance of building fabric also means reducing heat losses through linear thermal bridges, such as at junctions between building elements.
How does better energy efficiency improve people’s health?
The IPCC’s most recent assessment of climate impacts concluded, with high confidence, that the physical health of people globally has been adversely affected by global warming. Taking action to reduce greenhouse gas emissions can have the opposite effect, because it tends to reduce pollution (both internal and external) and result in healthier behaviours.
In buildings specifically, it results in warmer and more comfortable conditions. A BRE report published in 2021 highlighted that poor housing costs the NHS £1.4 billion a year. An article by the BBC attributed about half of that total to exposure to cold, stating that “exposure to indoor cold not only increases risk of respiratory and circulatory illness but may also harm mental health.”
Given that most of us spend around 90% of our time indoors, it is perhaps not surprising that tackling the energy efficiency of buildings stands to have the most positive impact on general health.
The LSHTM study also found that taking stronger action on greenhouse gas emissions leads to greater benefits. For buildings, that could mean aiming to go beyond building regulation compliance – such as constructing new buildings to the Passivhaus standard, and carrying out deep retrofit on existing buildings.
Avoiding adverse consequences from energy efficiency measures
Addressing energy efficiency must be done while thinking about the whole building. For example, the study describes how adequate ventilation must be provided alongside better building fabric, in order to avoid reducing indoor air quality and having adverse health consequences.
Something else that should be considered is, where possible, addressing thermal bridging heat losses at the same time as increasing insulation levels in the main building elements.
Psi values form part of compliance calculations in building regulations like Part L, but projects – whether new build or retrofit – don’t always take the time to properly design, calculate and construct high performance details.
AutoPSI, an online modelling tool developed by BRS Technology, aims to make junction detailing more accessible.
It offers quick and easy calculation of psi values in accordance with relevant standards and conventions, allowing users to aim for better energy efficiency. Details can be refined to meet regulatory requirements, deliver the best possible levels of performance, and – most importantly – contribute to more comfortable buildings that are healthier for occupants.
To find out more, visit the AutoPSI website.
