Heatwaves are on the rise – and millions of UK homes aren’t ready for them
This summer’s record-breaking temperatures are part of a pattern we can no longer ignore. Across the UK and beyond, heatwaves are becoming more frequent, more intense, and more disruptive.
The BBC’s recent documentary, Weather: Beyond the Forecast – Heatwaves: The New Normal?, brought this into sharp focus – offering a timely reminder that our homes, as they are today, are simply not built for the future.
From heat laboratories to firefighting helicopter pilots and even English vineyards, the film revealed a country quietly adjusting to something we once thought impossible: dangerous, destabilising summer heat.
But as the documentary posed the question “how hot is too hot?”, many of us working in home energy upgrades are left asking: why are we still failing to upgrade the homes we already have?
How hot is too hot? This BBC documentary takes a look at how extreme heat impacts people and environments in the UK.
A changing climate – and homes unfit for purpose
It’s a stark reality that around 18 million UK homes have an EPC rating below D. That means they’re leaking heat in winter, trapping it in summer, and costing more to run all year round. These are not just numbers – they’re a national vulnerability, hidden in plain sight.
In a warming world, poorly insulated homes become not just uncomfortable, but unsafe. Older housing stock is often more prone to overheating – especially in dense urban areas or where ventilation has been blocked to retain warmth – but some newer homes, particularly modern flats with large areas of glazing and limited ventilation, can be just as vulnerable.
That’s where retrofitting comes in. Retrofit simply means upgrading existing homes – improving insulation, ventilation, glazing, and heating systems – to make them more energy efficient and better suited to today’s climate. Done well, it helps people stay warm in winter, cool in summer, and keep their bills down all year round.
Meanwhile, new homes – often promoted as ‘eco’ – are too frequently built to the lowest acceptable standard, not to a level that will stand the test of time. Since 2016, poor construction choices have cost homeowners hundreds extra each year on energy bills, and left many new properties in need of retrofit themselves, despite being marketed as sustainable.
In recognition of the growing risks, the government introduced Part O of the Building Regulations in 2022 to reduce overheating in new residential buildings. It focuses on limiting solar gain through shading and window design, and promoting cross-ventilation – especially in urban settings. These are welcome steps, but the regulations fall short in other areas. Notably, they don’t advocate for using denser materials with higher heat decrement delay – which help slow the transfer of heat from the outside in. In a future of more frequent, intense heatwaves, material choices like these will be crucial.
We’ve heard the promises before: heat pumps will solve this, solar is the answer, the next wave of new builds will be better. But the truth is, the homes we already have are packed with embodied carbon. Upgrading them isn’t just practical – it’s one of the most effective ways we have to cut emissions and adapt to climate change without adding to the problem.
“People often think of retrofit as something technical or complicated – but at its heart, it’s about making homes work better for the people who live in them. Whether it’s staying cool in summer or warm in winter, the changes we make have a real impact on everyday comfort.” Geordie Stewart, Scheme Manager
Retrofitting is not just for winter
Much of the public conversation about upgrading UK domestic properties – known as retrofitting – has focused on winter comfort and reducing heating bills. That’s certainly part of the picture, but it’s only half the story.
In this new climate reality, retrofit is not just about energy efficiency. It’s about protecting our health, our comfort, and the value of our homes.
Good insulation doesn’t just keep heat in during winter – it also helps block heat from getting in during summer. Combined with thoughtful ventilation, external shading, and controlled airflow, it can turn a stifling night into one where you can sleep comfortably.
Often, keeping warm in winter and cool in summer are treated as separate challenges. But the same well-chosen materials can do both. When insulation is properly designed and installed, it helps stabilise indoor temperatures year-round – while managing moisture and improving air quality. That stability matters: big swings in temperature don’t just feel uncomfortable. They can trigger health problems, lead to condensation and mould, and even shorten the lifespan of building materials.
And we’re not talking about luxury upgrades. These are essential adaptations – many of them practical and reasonably affordable – designed to make our homes safe, healthy, and liveable in a changing climate.
It’s time to stop treating retrofit as optional
Retrofitting isn’t a fringe concern. It’s a mainstream solution. As the documentary makes clear, the climate is already changing, and the homes we live in must change too.
That means tackling a lack of investment, making it easier for homeowners to plan and carry out improvements, and giving local authorities the support they need to lead community-scale upgrades.
At Cosy Homes Oxfordshire, we meet many homeowners who care deeply about where they live – people who want their homes to be healthier, more comfortable, and better for the planet. Backed by Oxfordshire’s local councils and working with trusted local professionals, we see every day how thoughtful home upgrades can make a real difference. But we also see how hard it can be to know where to start, what to prioritise, or who to turn to for support.
That’s why making retrofit easier, clearer, and more trusted has to be part of the national conversation. It’s not just about comfort or cost—it’s about building resilience, and making sure our homes are ready for the future.
Looking ahead
Watching the BBC’s documentary, it’s hard not to feel the urgency. But it’s also an opportunity – to shift the conversation. We need to stop asking whether the heat is serious enough to act. It is. The question now is: what are we going to do about it?
Retrofit may not grab headlines, but it’s one of the most powerful tools we have to protect our homes, our health, and our future. While extreme heat continues to put people at risk, upgrading our homes offers a practical, lasting way to stay safe, cut emissions, and stay comfortable in a changing climate. It deserves a central place in the UK’s response – not someday, but now.
If you live in Oxfordshire and your home’s feeling the heat, now’s a good time to act. Do get in touch via our contact page.
Media or just curious? We’re always happy to share insights on how retrofit helps homes cope with rising heat.
