Editor's note: This brief was summarised by The Property AI Newsroom from a report by Mortgage Strategy. Read the original article for full details.

Over 100,000 Converted Flats at Risk of Becoming Uninhabitable in Heat

A major insurer has warned that more than 100,000 homes created from office-to-residential conversions in the UK could become “uninhabitable” during periods of high temperatures. Analysis by Zurich UK of government planning data found that 103,421 former commercial buildings have been developed into homes over the last decade, many of which are not adequately equipped for rising temperatures.

The report highlights a 58% surge in commercial-to-residential conversion applications in just three years, as companies reduce office space. The demand for housing stock has led to a growing number of converted homes that may not be built to withstand fluctuating and extreme temperatures.

According to Zurich, many of these conversions are at risk of overheating because office buildings were not originally designed for 24/7 residential use. Issues identified include poor airflow due to sealed windows and limited ventilation, large glass façades that amplify heat, lack of external shading, and the use of outdated materials in older buildings. Some conversions also have weaker plumbing and services, particularly where these have been retrofitted.

The insurer notes a regulatory gap, as commercial-to-residential conversions typically fall outside of new build housing standards on issues such as overheating. Central urban locations, where many offices are based, are often hotter, with London identified as the UK city least-adapted to hot weather due to poor ventilation in both offices and homes.

Research cited in the report from The Grantham Research Institute on Climate Change and the Environment at LSE found that half of all UK homes are at risk of overheating, with this figure projected to rise to 90% under a 2°C global warming scenario. While building regulations now address overheating risks in new-builds, existing buildings are excluded, despite the UK having one of the oldest and least efficient building stocks in Europe.

The report also notes that homes not resistant to heatwaves pose significant health risks. The Climate Change Committee estimates that heat-related deaths in the UK will increase by around 250% by the 2050s.

This information is particularly relevant for letting agents and inventory clerks, as the risks associated with overheating and building durability may impact property management, tenant safety, and maintenance requirements.