An estimated 441,000 private rented homes in England failed thermal comfort standards in 2024, accounting for 40.3% of all non-decent private rental properties, as major reforms to the Housing Health and Safety Rating System (HHSRS) came into force last month.
Inventory Base analysed the latest Decent Homes Standard (DHS) data published by the government, alongside details of the revised HHSRS framework. The analysis examined the prevalence of thermal comfort failures across England’s housing stock and considered the implications of the updated housing safety regime, which introduces a renewed focus on temperature-related hazards, including overheating.
The findings show that thermal comfort is one of the most common issues affecting housing quality across England. While the number of non-decent private rented homes has fallen by -16.5% over the last decade, there were still almost 1.1 million ‘non-decent’ private rental properties recorded in 2024.
The updated HHSRS framework reduces the number of hazard categories from 29 to 21, replaces the previous A-J rating bands with a simplified High, Medium, and Low risk classification system, and introduces new baseline indicators designed to help identify potential deficiencies before a full assessment takes place.
Among the hazard categories are those relating to physiological requirements, including both excess cold and excess heat. Excess heat hazards can arise from factors including excessive solar heat gain, inadequate shading, poor ventilation, and building characteristics that make it difficult to maintain safe indoor temperatures.
Under the revised framework, local authorities will have powers to intervene where overheating presents a significant risk to occupants’ health.
Sián Hemming-Metcalfe, Operations Director at Inventory Base, said: “As the UK’s climate changes, property professionals are increasingly having to consider how homes perform during periods of extreme summer heat.
“June’s prolonged heatwave, which saw temperatures exceed 35°C in parts of the country, has brought that challenge into sharp focus. While thermal comfort deficiencies under the revised HHSRS framework are distinct from overheating hazards, both highlight the growing importance of ensuring homes remain safe and habitable throughout the year.”