How can we future proof our cities against extreme heat?

Soaring temperatures and dangerous heat waves are becoming an uncomfortable reality for cities across the world, including those in the UK.

July 2023 was the world’s hottest month on record, with wildfires raging throughout southern Europe and temperatures tipping off the scale globally, prompting UN secretary general António Guterres to announce: “The era of global warming has ended and the era of global boiling has arrived.”

So, in the era of ‘global boiling’, what resources and approaches are available to real estate owners and investors to boost the resilience and long-term profitability of their urban portfolios, while keeping tenants and residents safe?

Instances of extreme heat are poised to rise steeply in frequency and severity over the coming decades, with higher-temperature days and longer, more frequent heatwaves, particularly in cities where urban heat islands form due to the heat-absorbing properties of urban surfaces. Such temperatures increase risks to health and safety, lead to higher energy use for cooling and create potential for costly structural degradation.

The contemporary built environment is a clear contributor of extreme heat, yet it can also be an important part of the solution, particularly in cities, where there are opportunities to adopt mitigation strategies that directly reduce temperatures and adaptive measures that help people and businesses cope with the impacts of extreme heat.

Although there is no one-size-fits-all approach to managing extreme heat in cities, given different humidity levels and other local conditions, a suite of potential options is available, many of which build amenity value and address other environmental or regulatory aims such as city greening, air quality improvement and energy conservation.

Building design, materials and the preservation of vegetated open space are all key strategies that can help to future-proof urban real estate in vulnerable markets, simultaneously lowering operation and management costs while improving user safety and experience.

Building design principles can help prevent the absorption of heat by incorporating light-coloured or reflective surfaces and materials, as well as providing direct cooling via increased shade from built and natural canopies.

The implementation of energy efficient strategies such as passive cooling and wind channelling are other ways that urban developers and designers are working to make urban buildings more adaptable to high temperatures and more comfortable for users.

Urban biodiversity is another critical piece of the puzzle. Trees and vegetation deliver essential environmental services by providing shade, reducing the severity of the urban heat island effect, improving air quality and managing rainwater, and cities offer an immense canvas to cultivate biodiversity through the addition of green corridors, walls and roofs.

As the climate crisis intensifies and with temperatures set to continue rising globally, it’s clear that significant investment and new modes of operating will be required by diverse stakeholders to ensure that life in our cities can continue for years to come.

Without intervention, the impact of extremely high temperatures – on real estate developments, infrastructure and the economy in our cities – could be substantial.

Learn more about how cities can be future proofed against extreme heat in this series of reports by the ULI:

Scorched: Extreme Heat and Real Estate

Scorched: Extreme Heat and Real Estate in Asia Pacific