CIBSE has once again been recognised for its expertise in tackling one of the most pressing challenges in the built environment – overheating in homes. In a recent BBC article exploring unconventional yet effective ways to mitigate rising indoor temperatures during heatwaves, Dr Zoe De Grussa, CIBSE’s Research Manager, was featured as the expert voice.
The BBC story highlights a novel experiment by Loughborough University involving the use of Greek yoghurt as a temporary reflective coating on windows to help reduce indoor temperatures.
Dr Ben Roberts, Senior Lecturer in Healthy Buildings at Loughborough University, said that applying yoghurt to the exterior of windows can reduce indoor temperatures by as much as 3.5°C.
In May, Dr Roberts and PhD student Niloo Todeh-Kharman ran an experiment using two identical test houses at the university, applying yoghurt to the windows of one but not the other. The house with yoghurt-coating was on average 0.6°C cooler indoors, with peak differences reaching 3.5°C during hot, sunny conditions.
The idea originated from a conversation with Tom Greenhill, creator of the Heatwave Toolkit website, who was exploring low-cost methods to reduce overheating. Greenhill had tried yoghurt on his own home, but it had not been scientifically tested until now.
The researchers used a supermarket-brand Greek yoghurt with approximately 10% fat content for the study.
While the idea may sound unusual, the trial showed a notable drop in internal temperatures – up to 3.5°C – demonstrating the potential of low-cost solar control measures in helping to keep homes cooler during extreme heat.
Quoted in the article, Dr De Grussa emphasised the science behind this approach:
“It’s not your everyday hack, I would say, but anything you can do to put on the outside of windows is going to be of benefit to stopping sunshine coming in and heating up the internal environment.”
Her contribution not only reinforces the importance of solar shading and overheating mitigation – both key themes in CIBSE’s published guidance – but also places the Institution firmly in the national spotlight as a trusted authority on building performance, health and wellbeing.
This recognition underscores CIBSE’s ongoing commitment to providing evidence-based knowledge and practical solutions to improve indoor environments, especially as climate change continues to drive more frequent and intense heat events across the UK.
Stay informed with the latest guidance and research from CIBSE on mitigating overheating and improving occupant comfort by visiting Overheating Position Statement | CIBSE