2025 was the hottest British summer on record, and organisations must do more to protect staff as extreme systems become the norm. Rebecca Stewart outlines how to build more protection into our offices.
Europe has entered a new climate reality. Now the fastest-heating continent, this summer’s heatwaves – 46°C in Spain, 43°C in France, and even 34°C in Norway – are no longer anomalies. The Met Office’s declaration of extreme weather as the UK’s ‘new normal’ is a stark reminder that our built environment needs to evolve, and quickly.
Workplaces, in particular, are under strain, with building developers and employers feeling the pressure. Designed in cooler eras to retain warmth, many UK buildings now trap heat, leaving employees uncomfortable and businesses grappling with reduced productivity. The challenge is clear: our indoor spaces need to become resilient to rising temperatures, without compromising sustainability. Indeed, the opportunity is there to attract staff into the office by giving them a cooler, more comfortable environment.
Outdated approaches
Scaling up traditional air conditioning isn’t a viable fix. Many older systems are inefficient, disruptive and poorly matched to today’s open-plan office designs. Instead of improving comfort, they often introduce new issues – uneven cooling, uncomfortable drafts, intrusive noise and higher energy consumption. While alternative solutions hold greater promise, they’re often impractical in existing buildings. Urban noise and pollution limit the effectiveness of natural ventilation, while structural constraints make installing underfloor cooling systems a complex and, in some cases, impossible undertaking.
At the same time, tearing down and rebuilding our way to climate resilience is not the answer. The environmental cost of such an approach would be staggering. Most of the buildings we’ll rely on in 2050 are already standing; replacing them wholesale would significantly increase carbon emissions. With the built environment already contributing around a quarter of the UK’s greenhouse gas emissions, we are, vitally, upgrading what we have, but retrofit isn’t easy.
Rethinking cooling
The cooling industry has remained largely unchanged for decades. But now, engineers are beginning to reimagine what cooling can look like in a warming world. Heat pump-enabled systems are gaining traction, and regulations around F gases are pushing the sector towards more sustainable cooling methods.
This change is not just technical. We’re experiencing a complete mindset shift when it comes to incorporating sustainability and comfort into building design. From smart buildings to efficient and effective layouts, building owners and tenants can keep people cool with technologies that are energy-efficient, low-carbon and affordable.
Priorities for progress
To accelerate this transformation, continued progress can come from three key areas. First, we have to rethink how air conditioning is integrated into buildings. This means no longer designing systems around the ‘peak load scenario’ all the time, and ensuring cooling solutions perform efficiently to enhance the comfort of workplaces during extreme temperatures.
Second, policy and procurement can play a stronger role in driving change. Incentivising the adoption of low-emission, easily retrofittable systems helps drive decarbonisation across the built environment, making sustainable cooling the norm rather than the exception.
Third, we shouldn’t forget the importance of rooting innovation in the fundamentals. By revisiting the first principles of physics, we can develop cooling technologies that use fewer materials and eliminate the need for high GWP (global warming potential) refrigerants. This approach is essential for reducing embodied carbon and improving energy efficiency at scale, for the benefit of planet and people.
Flexibility is key
Beyond design, policy and physics, flexibility is vital. Anyone who’s worked in an office knows the struggle: thermostat battles, cold draughts, and the constant hum of outdated units. On the flip side, extreme heat can zap concentration and deter people from going into the office altogether.
Temperatures fluctuate throughout the day, and so do people’s needs; facilities managers consistently report that being too hot or too cold is the top complaint from building occupants. With the wealth of data now available, ‘flexible cooling’ systems present an exciting opportunity to respond in real time to changing conditions and preferences, ensuring that comfort is the norm rather than a luxury.
Shorter commercial leases also add another layer of complexity. As building usage evolves more rapidly, cooling systems should be adaptable – capable of supporting diverse layouts requested by employers encouraging their people back to the office, without requiring costly and wasteful replacements.
A smarter path forward
As extreme heat becomes a common feature of our summers, improving how we use our existing buildings through innovating cooling technology means we can avoid the carbon-intensive construction of new buildings, and deliver low-carbon air conditioning without the need to rebuild from scratch. And beyond environmental benefits, improved indoor spaces attract higher rents because they better serve the people who use them every day.
We know cooling is no longer an afterthought – it’s a cornerstone of climate resilience, workplace wellbeing and public health. As temperatures rise, so too should our ambition and innovation.
Rebecca Stewart is CEO at Artus Air, a specialist in low emission heating, cooling and ventilation systems.
Image: Illia Horokhovsky / Unsplash
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