The record-breaking temperatures experienced across the UK during June have reinforced growing concerns about the impact of extreme heat on both construction workers and the built environment. While much of the public focus has centred on soaring temperatures, experts are warning that heatwaves are becoming an increasingly significant challenge for the construction and property sectors, affecting worker safety, project delivery and the long-term resilience of buildings.

Research from the University of Reading suggests the industry remains underprepared for increasingly frequent periods of extreme heat. A study involving 307 construction workers and managers found that 67% of site workers are concerned about the impact of heat on their health, while 44% reported experiencing a heat related illness, including heat stroke, heat exhaustion or dehydration. The research also found that 87% felt more tired during hot weather, 61% experienced reduced concentration and 58% reported becoming more irritated, highlighting the effect that prolonged periods of heat can have on wellbeing, productivity and site safety.

Dr Alba Fuertes, from the University's School of the Built Environment, believes the issue can no longer be viewed as a future challenge. She explained: "Heat is already a danger for workers on construction sites and other outdoor workplaces on warm days, not a problem for some distant summer." Despite this, the research found that many organisations continue to rely on individual judgement rather than structured planning, with more than half of workers surveyed reporting they had received no compulsory training on managing heat.

The impact of prolonged hot weather extends well beyond construction sites. Heatwaves are placing increasing pressure on the UK's ageing building stock, with dry conditions increasing the likelihood of subsidence, movement within masonry and the deterioration of external materials. Nicholas Donnithorne, UK Technical Manager at Peter Cox, explained that early warning signs are often easy to miss, noting: "The earliest signs of heat-related property damage are often subtle. The most common indicators of deterioration from heat include sticking windows and doors, gaps forming in woodwork and small, hairline cracks in render and mortar joints."

He also warned that more significant structural issues may develop over a much longer period. "Serious issues like subsidence take some time to appear as they generally result from prolonged moisture loss in the surrounding soil [...] Clay soil is the most susceptible to this, and with more extended periods of dry weather on the horizon, it's certainly something property owners should be aware of." Donnithorne added that simple maintenance measures, including keeping gutters, drains and soakaways clear, can help reduce the risk of damage when heavy rainfall follows prolonged dry weather.

With forecasts suggesting hotter summers are becoming an increasingly regular feature of the UK's climate, experts agree that adaptation will become increasingly important. Alongside improved workplace guidance and practical heat management measures, greater consideration must also be given to designing, maintaining and retrofitting buildings so they are better equipped to withstand rising temperatures. As the construction industry responds to a changing climate, improving resilience across both sites and the built environment is likely to become an essential part of protecting workers, property and communities.

This is a preview of a feature that will appear in the upcoming Design and Build UK Edition 19.08