Measures to help cities Cope with upcoming heatwave

Meteorologists expect high temperatures across the Czech Republic at the end of this week and into next week. In densely built urban areas, the combination of heat-retaining surfaces and limited greenery can create heat islands, where temperatures remain high even at night. According to Gregor Grassl, Associate Partner and Head of Green Urban Development at Drees & Sommer, strategies such as external shading, green facades and roofs, and thermally efficient building materials can help maintain indoor comfort.

Well-planned measures, Grassl notes, can reduce heat stress, improve air quality, enhance biodiversity, and make cities more resilient to climate change. Drees & Sommer has supported several German cities, including Düren, Dormagen, and Rastatt, in implementing such solutions.

Increasing urban shade through tree planting, adding green facades, and replacing impermeable surfaces with breathable materials can improve microclimates. In Dormagen, drinking fountains have been installed in public areas to promote hydration and reduce heat-related health risks. Light-colored, reflective materials can lower surface temperatures, particularly on roofs and paved areas.

Grassl cautions that reliance on air conditioning can worsen outdoor heat. Instead, low-energy cooling strategies—such as night ventilation with stored thermal mass, underfloor cooling, and seasonal thermal storage—can reduce the need for mechanical systems. At the district scale, shared low-energy networks can alternate between heating in winter and cooling in summer.

Urban design also plays a role: higher buildings can shade each other and promote air circulation if window areas are kept to a manageable proportion.

Across Europe, adaptation measures are becoming more common. Examples include Paris’s “Schoolyard Oasis” project, Vienna’s temporary “cool streets,” and Rotterdam’s Benthemplein water square, which combines water management with cooling features.

Source: Drees & Sommer