Responding to the Environmental Investigation Agency’s latest cooling report, Stuart Dantzic, managing director of solar shading manufacturer, Caribbean, and vice president of the British Blind and Shutter Association (BBSA) calls for a passive-first approach to tackling overheating.
The Environmental Investigation Agency’s UK Cooling Policy in a Warming World report should prompt a fundamental rethink of how the UK tackles overheating. As our climate continues to warm, relying on air conditioning alone is neither sustainable nor economically viable. Preventing buildings from overheating in the first place has to become the priority.
The report’s call for a National Cooling Action Plan rightly places passive cooling measures ahead of mechanical cooling. That mirrors the recently published Ladder of Cooling from ES-SO, which identifies external shading as one of the most effective ways to reduce solar heat gain.
The challenge is that overheating has historically been treated as a secondary consideration within the built environment. Energy efficiency has rightly focused on reducing heat loss during colder months, but the same buildings that perform well in winter can become vulnerable during prolonged periods of summer heat if solar gains are not properly managed.
This is particularly important as the UK enters an era of more frequent heatwaves. Retrofitting buildings to cope with rising temperatures requires a different mindset: one that considers how buildings interact with the sun, ventilation, occupants and the external environment throughout the year, rather than simply adding cooling equipment when temperatures rise.
Let’s be frank: we wouldn’t think of heating a building without first insulating it, so why are we still discussing cooling buildings before preventing excessive solar heat gain?
As vice president of the BBSA, I’m proud of the work being done to strengthen the evidence for external shading. Robust research is essential if we’re to change the way buildings are designed and retrofitted.
Current studies at Loughborough University, using matched test houses, are demonstrating how different forms of external shading reduce overheating. Earlier research on matched London flats found that external shading reduced peak indoor temperatures by as much as 19.5°C during periods of hot weather.
One point that is often misunderstood is that external shading doesn’t cool a building. It prevents the building from heating up by stopping solar radiation before it passes through the glazing. That’s a crucial distinction.
External shading should also be viewed as part of a wider approach to climate-resilient design. It works alongside good ventilation, appropriate glazing, insulation and thoughtful building orientation to create spaces that remain comfortable without excessive reliance on energy-intensive solutions.
This is especially important when considering the scale of the retrofit challenge facing the UK. Installing air conditioning in millions of homes is unlikely to be a realistic or sustainable solution, particularly when demand for cooling is likely to increase at the same time as pressure on the electricity grid grows.
It also explains why user behaviour, and increasingly intelligent automation, are so important. External shading only delivers its full benefit when it is deployed at the right time and in the right position.
As an industry, we need to consider how we can support a more sustainable approach to cooling buildings. The EIA report raises several important questions:
• Have we become too dependent on mechanical cooling instead of addressing the root causes of overheating?
• Should passive measures such as external shading become a standard part of building design rather than an optional upgrade?
• Is it time for Building Regulations and retrofit programmes to give external shading far greater prominence?
• Should the industry adopt a genuine passive-first approach to overheating, in the same way that fabric-first transformed energy efficiency?
The shift towards a warmer climate means we need to rethink how we design, build and adapt our homes and buildings. Passive cooling can no longer be viewed as an optional extra, but as a fundamental part of creating comfortable, resilient and energy-efficient spaces for the future. External shading has a vital role to play in that transition, helping to prevent overheating before more energy-intensive solutions are required.
