The UK's schools are facing a crisis of overheating, with internal temperatures in some classrooms reaching as high as 40C during the summer months. This has led to concerns over pupil welfare, educational disruption, and a negative impact on learning outcomes.
According to Harry Paticas, director of Retrofit Action for Tomorrow, a combination of outdated design principles and the removal of historical cooling features has turned many schools into 'heat traps'. Modern schools, particularly those built during programmes like 'Building Schools for the Future' in the early 2000s, often feature large glass atriums and extensive glazing, which was originally intended to maximise natural light. However, this now contributes to significant heat gain, exacerbated by single glazing that allows up to 37% more heat into a building than double glazing. Additionally, safety restrictors on windows often prevent adequate ventilation.
Victorian-era school buildings, designed with passive cooling techniques such as tall sash windows for cross-ventilation and external shutters, have largely lost these benefits due to refurbishments, changing safety standards, or simply painted-shut windows. This has left older structures vulnerable to overheating. The problem is not limited to classrooms – the majority of school playgrounds are covered in tarmac, lack tree cover, and function as giant heat radiators, with temperatures reaching up to 60C during heatwaves.
Retrofit Action for Tomorrow's engagements with 80 schools across England revealed that 68% experienced overheating, with more than a quarter classifying it as 'significant'. Teachers have reported instances of pupils fainting or vomiting in class due to the heat, leading to school closures, cancelled exams, and missed study time. This not only presents a critical safeguarding issue but also negatively impacts learning outcomes.
While long-term retrofitting is essential, some immediate measures can offer relief. These include external shading using fabric on windows, which is twice as effective as internal shading, or even coating glass with a specially designed yoghurt-like substance that reduces heat gain. Guidance is also available on optimal window and blind management.
The issue of overheating is just one aspect of the climate challenges facing UK schools, which are also expected to contend with increased flooding, water scarcity, and more frequent extreme weather events in the coming decade.