Overheating in UK homes: the future is already here

This month, a warning was issued by the Climate Change Committee that overheating in UK homes was critical. In a letter to government, it was highlighted ‘Planning for global warming levels reaching 2°C above preindustrial levels by 2050 should be a minimum level’ and lobbied for a ‘framework of clear long-term objectives’ to be set out in the next National Adaptation Programme (NAP)’.

This sparked renewed debate around how we can address overheating in the future. However, the reality is that the future is already here.

Pre-industrial Britain saw heatwaves once every 50 years and historically, UK heatwaves occurred at most once a year. We have seen four heatwaves in 2025 alone and in August, The Met Office confirmed that summer 2025 was officially the hottest on record.

It is my opinion that as much as people will try to refute it, the fact is, it has everything to do with climate change. As the topic is debated across dinner tables and in government, the fact is the UK's five hottest summers on record have all occurred in the last 25 years.

As part of my role at VEKA, I am involved with many industry bodies and take an active role in consultation periods and regulatory reviews, including industry shifts such as Future Homes Standards expected to be published in the near future.

Current building regulations recognise the challenges posed by ageing housing stock. With over five million UK homes that were built before 1945, many remain poorly insulated and were never designed to cope with the hotter summers or wetter winters we experience in the current day. The simple fact remains that many of these houses are terraced and 1930s suburban semi-detached properties which have smaller rooms and limited window openings, offering fewer opportunities for effective natural ventilation and cooling.

There is an evidential need for robust regulations, and increased consumer awareness of how to manage overheating in properties. Only through proactive adaptation and smarter building design can we ensure that UK homes remain comfortable and fit for the future.

Government recognition and regulatory gaps

Government consultation within recent years has started raising more questions about overheating in buildings, which suggests a potential regulatory review is on the horizon. This represents a shift in thinking, as authorities begin to acknowledge what the construction and fenestration industry has long understood; overheating is becoming a critical issue for UK homes.

However, the current regulatory framework reveals a major gap in addressing this growing problem. Overheating documentation and requirements within building regulations currently only cover new builds, affecting approximately 160,000 to 170,000 house completions per year across Great Britain. While this is a positive step, it represents just a fraction of the housing stock that requires attention.

The requirements don't cover existing dwellings, and they don't cover change of use. As more buildings are converted from offices into apartments, we're missing opportunities to address overheating at the design stage. So, whilst we have new homes being built to improved standards, existing homeowners must take voluntary action, otherwise we will continue to suffer with overheating issues on a much larger scale.

What can we learn from Europe?

Ultimately, if you want to stop heat from getting into a building, you must stop it on the outside. We can implement simple changes such as closing curtains on hot days and ensuring we don't open windows to let hot air in during peak temperatures, but we must also look to improve external shading solutions.

As a nation, we must consider looking to our European counterparts who combat this issue using inward opening windows combined with external shutters. Walk through any European city and you'll see buildings designed with external shading as standard, not as an afterthought or aesthetic compromise, but as an integral part of comfortable living.

By contrast, in the UK, we have outward opening windows and we don't put shutters on the outside of our buildings – largely for aesthetic reasons. Yet external blinds and shutters are far more effective than any internal solution because they prevent solar gain from entering the building envelope in the first place. Having blinds between two panes of glass helps, but you've still allowed heat to penetrate the first layer of glazing. The challenge has always been getting people to understand the benefit.

Modern fenestration solutions

The glass industry has had solar control coatings built into glazing for some time, which reduce heat gain through glass while still permitting natural light. Low emissivity coatings, which work for reduction of heat loss also work in reverse to reduce energy gain. However, these represent just one part of an approach to thermal comfort.

Modern PVCu window systems offer solutions through advanced design. At VEKA we have the established M70 system and the newer Softline 82 - Passivhaus both of which demonstrate how contemporary fenestration can address overheating challenges through smarter design features. The multi chambered profiles provide enhanced thermal performance in winter, while tilt and turn functionality offers superior ventilation control, especially in high-rise buildings and flats.

Tilt and turn windows are particularly effective because they allow occupants to manage airflow precisely. In tilt mode, they provide secure night ventilation at the top of the frame, enabling hot air to escape while maintaining security. In turn mode, they can create effective cross ventilation when used strategically throughout a building.

Triple glazing within these systems provides additional benefits beyond thermal insulation. The gas filled cavity helps create barriers to solar heat gain, the multi chambered frame design further enhances thermal break performance, reducing heat transfer through the window system itself.

The path forward

The fenestration industry has the solutions to address overheating, but implementation requires a combination of regulatory evolution, industry education, and consumer awareness. Modern window systems like VEKA's M70 and Softline 82 - Passivhaus series offer the thermal performance, solar control and ventilation capabilities needed for the UK's changing climate, but we cannot address these challenges with modern glazing alone.

We need to embrace continental European approaches to external shading while leveraging British innovation in PVCu systems. The regulatory framework must evolve to address existing buildings and change of use conversions, not just new builds.

As we prepare for future heatwaves, the lesson is clear. Effective overheating mitigation requires integrated solutions that combine intelligent building design, advanced fenestration systems, and homeowner education. The products and knowledge exist, now we need the will to implement them comprehensively across the UK housing stock.