Designing cooler cities

As extreme temperatures grow increasingly severe across the globe, their impacts extend far beyond the visible damage to crops or forests. Human health is under serious threat, making urban heat mitigation strategies more important than ever. A study published in Nature Medicine on July 10, 2023, revealed a staggering statistic: 61,672 heat-related deaths occurred in Europe between May 30 and September 4, 2022. Germany alone reported 8,173 of these tragic fatalities. This data underscores the urgent need for cities to adapt to rising temperatures and implement effective urban heat mitigation strategies to safeguard public health and well-being

Importance of urban thermal analysis

An interesting example of the urban heat challenge can be seen in the above simulation of the night-time air temperature in Vienna on a summer evening. The simulation showed the sharp contrast between the cooling breeze from the Danube and the oppressive heat trapped in the city’s densely built areas. This case highlights the importance of thermal analysis in urban planning to identify and mitigate heat hotspots (read more).

ENVI-met for Better Urban Planning

This brings to light a crucial consideration for architects, landscape architects and environmental designers: the importance of analysing and simulating architectural designs or urban planning concepts before they come to fruition. The reasons for this are profound and multifaceted.

Most importantly, understanding outdoor thermal comfort is essential to creating environments that promote human comfort and well-being. By carefully evaluating factors such as solar radiation, wind patterns and shading, architects and environmental designer can shape cities and public spaces that moderate extreme heat. This proactive approach ensures that urban environments provide a more pleasant experience for pedestrians and residents, even on the hottest days.

This is where ENVI-met comes in, being the state-of-the-art simulation software that models microclimates in urban areas. It allows architects and planners to analyse the impact of their designs on the local climate by simulating the interactions between buildings, vegetation and atmospheric conditions. Using ENVI-met, professionals can visualise and predict how different design choices – such as the placement of trees, the orientation of buildings or the use of reflective materials – will affect thermal comfort and microclimate conditions (read more about ENVI-met).

Addressing the Urban Heat Island Effect

In addition, the phenomenon known as the urban heat island effect, where urban areas experience significantly higher temperatures than their rural surroundings, is a major challenge. This effect is caused by factors such as dense buildings, extensive tarmac surfaces and reduced vegetation. ENVI-met can be used to simulate the Urban Heat Island Effect, helping urban planners to identify areas of high thermal discomfort and to implement effective mitigation measures. These can include urban greening, the use of reflective surfaces or the introduction of strategically placed shade structures, all of which can significantly reduce the intensity of urban heat (explore solutions).

Adapting to a Warming World

As global temperatures continue to rise, the need to adapt our built environments to these new realities becomes increasingly urgent. By understanding the risks associated with heat stress, strategies that incorporate adaptive solutions can be developed. These solutions can range from designing cool corridors that channel refreshing breezes through urban spaces, improving access to shaded areas, selecting materials that reflect rather than absorb heat, and creating architectural designs that promote natural ventilation. ENVI-met supports this by allowing different design scenarios to be tested to find the most effective heat mitigation strategies (read more about adaptive strategies).

Protecting Public Health

In addition to improving comfort and mitigating heat, these strategies play a critical role in protecting public health. The serious health effects of excessive heat, as highlighted by the alarming death toll in the recent study, cannot be overstated. By closely monitoring outdoor thermal conditions and designing spaces with heat mitigation in mind, authorities can issue timely heat advisories or warnings. This not only protects the general public, but also ensures that outdoor events and public gatherings can take place safely, with the necessary precautions (how to protect public health).

Building Resilient Cities for the Future

In conclusion, the role of architects, landscape architects and environmental designers has never been more important. As heatwaves become an increasingly common and dangerous aspect of our climate, the responsibility to create urban environments that protect and enhance human life is paramount. By integrating tools such as ENVI-met for thermal comfort analysis, urban heat mitigation and adaptive design strategies into every project, we can build cities that are not only livable, but also resilient in the face of a changing climate (more on resilient urban design).

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