Heatwaves and Health: The ARCADE Project Tackling the Silent Threat of Overheating Homes

Ensuring homes are both energy-efficient and heat-safe in a warming world.

As Britain swelters under increasingly frequent and intense heatwaves, a new crisis is emerging - one that is playing out not on city streets, but inside homes. The UK’s record-breaking heatwave of 2022, which saw temperatures soar above 40°C, led to more than 3,200 excess deaths in England and Wales. Many of these deaths were among older adults and people with pre-existing health conditions, highlighting a growing but often overlooked public health emergency.

While much of the climate change debate has focused on reducing emissions and winter fuel poverty, researchers warn that the way homes are being upgraded for energy efficiency could inadvertently be putting lives at risk. Efforts to insulate and seal buildings against the cold may also trap dangerous heat inside during summer, leaving vulnerable residents at risk of overheating.

"The way we design and upgrade homes needs to change—fast," says Professor Rajat Gupta, Oxford Brookes lead investigator on the ARCADE project. "If we don’t act now, more lives will be at risk as heatwaves become more frequent and intense."

A new NERC-funded £2 million research initiative, the ARCADE (Accelerating Resilience and Climate Adaptation of Domestic Environments for Vulnerable Population) project, jointly run by UCL, Oxford Brookes University and London School of Hygiene and Tropical Medicine is aiming to tackle this problem head-on by providing decision-makers with the data and tools needed to protect those most at risk. The project will investigate how different types of housing—particularly retirement villages and social housing—expose older residents to indoor overheating, and explore ways to make homes both energy-efficient and heat-safe in a warming world.

It’s well established that rising outdoor temperatures are linked to increased deaths and illness, particularly among older adults and those with heart, lung, or neurological conditions. But climate vulnerability isn’t just about the heat outside—it’s also about what happens indoors. Most people, especially older individuals, spend the majority of their time inside their homes, meaning the risk of overheating depends heavily on the design and condition of the buildings they live in.

Cities, in particular, face an added risk due to the urban heat island effect, where dense areas of concrete and asphalt trap and amplify heat, making already high temperatures even more extreme. In homes that lack proper ventilation, shading, or cooling solutions, indoor temperatures can climb to dangerous levels.

Led by experts in the built environment, health, and systems thinking, the ARCADE project will take a multi-faceted approach to understanding and mitigating heat risks. Researchers will monitor indoor temperatures in different types of housing, conduct surveys with residents, and use advanced computer modelling to simulate future climate conditions. The project will also assess the effectiveness and cost of different overheating mitigation strategies, from better ventilation and shading to new building materials and designs.

According to Rajat, the ARCADE project takes a unique approach by integrating science with policy action. “We’re not just studying the problem—we’re working with policymakers, housing developers, and healthcare professionals to implement real solutions that can protect vulnerable communities.”

Crucially, ARCADE isn’t just an academic exercise—it’s designed to produce real-world solutions. The project will bring together policymakers, local authorities, healthcare professionals, construction industry leaders, and climate experts to ensure that findings translate into action.

Despite the growing evidence of climate-driven health risks, policies around housing and heat adaptation remain fragmented. The UK’s Net Zero commitments have prioritised energy efficiency, but overheating risks are not always considered in retrofit strategies.

"Our research shows that overheating in homes is a serious but solvable problem," says Rajat. "By designing and retrofitting homes with climate resilience in mind, we can ensure that future heat waves don’t become public health disasters."

With the UK’s population ageing and extreme heat events becoming more common, the country faces a stark choice: rethink how homes are designed, retrofitted, and regulated, or risk thousands more avoidable deaths. The ARCADE project could be the key to ensuring that the future of housing isn’t just energy-efficient, but climate-resilient.