It’s getting hot in here! Heat risk to buildings

The recent heatwave in Canada has brought into focus the real and present dangers of extreme weather conditions. Record temperatures in British Columbia, reaching as high as 49.6°C, resulted in hundreds of excess deaths and heat-related hospital visits. As early analysis shows the heatwave would have been ‘virtually impossible’ without human-caused climate change, we know to expect an increase in the frequency of such events, presenting a global challenge for the buildings in which we live and work.

In the UK, the Climate Change Committee (CCC) have recently released their third assessment of the UK’s readiness for the impacts of climate change. The Climate Change Risk Assessment (CCRA3) paints a stark picture of the widening gap between the risks posed by the UK’s changing climate and the government’s policy response. Among the highest priority areas identified by the CCC, they highlight ‘risks to human health, wellbeing and productivity from increased exposure to heat in homes and other buildings’ as requiring urgent action before the next round of national adaptation policies due in two year’s time.

What is the risk?

Average annual temperatures in the UK have already increased by 1.2°C since pre-industrial levels, and are expected to rise further. Summers as hot as 2018 (the joint hottest on record) could occur every other year by 2050, with an increasing likelihood of exceeding 40°C, according to the Met Office’s UK Climate Projections.

Without suitable adaptation measures, cities will become increasingly uncomfortable places to live – the dense concentration of buildings and paved surfaces in urban areas causes an increase in temperature relative to the surrounding countryside, known as the urban heat island effect. This will increase the number of ‘tropical nights’, hot and humid evenings that are a significant contributing factor to heat-related deaths during heatwaves.

More than 2,500 people died during heatwaves in 2020, the most of any year since records began. Continued warming, and current adaptation measures could see this figure triple in coming decades.

In the five years since the previous report (CCRA2), 570,000 homes have been constructed in the UK and under current government targets another 1.5 million will be built by the time CCRA4 is published. If buildings are not designed to cope with the increasing temperatures, there is a real risk that climate vulnerability is ‘locked in’ to our infrastructure.

What are the implications?

Of the many risks discussed in the report, the CCC singled out the risk of heat in buildings as being particularly notable for the absence of adaptation policy.

There are two years until the next round of national adaptation policies must be submitted; two years that are vital for closing the adaptation deficit. With consultations taking place in England and Wales, it is likely that policy will follow. It is therefore essential that this risk must be considered now, for both standing and development assets.

At EVORA, we can work across the entire life cycle of a project, to help deliver on better building design and operation. As well as helping to reduce the embodied carbon in the materials used in construction, improving resilience to high temperatures can be worked into the building at the design stage to reduce climate vulnerability. This could include measures such as:

• Passive cooling measures – better shading, more reflective surfaces, and improved ventilation are often the most cost effective ways of reducing the pressures of high heat;
• Choice of materials – through well informed decisions around the choice of materials, it is possible to create a more comfortable internal environment, whilst also reducing the embodied carbon in construction;
• Green roofs and rooftop gardens – as well as the obvious boosts to biodiversity, green roofs reduce heat by providing shade, and through the cooling effect of evapotranspiration.

Further to this, through our partnership with Moody’s 427, we are able to incorporate physical climate risks, including those posed by increasing temperatures, into our SIERA platform. This enables our consultants to analyse physical risks on an asset-level basis. This detailed information can then form the basis of best-practice climate resilience measures across a real estate portfolio.

If you would like to know more, speak to our experts today: [email protected]