Heatwaves are no longer a summer anomaly. They have become one of the most serious and direct threats to public health in urban environments. However, heat does not affect everyone equally. A recent study by the SAREN research group at the University of the Basque Country (EHU), as part of the OLADAPT project, has put figures and maps to this reality: the risk posed by high temperatures varies dramatically from one neighbourhood to another, and even between neighbouring buildings.

By analysing three cities with very different climates—Bilbao, Madrid and Cáceres—the research team has shown that thermal vulnerability is not simply a matter of temperature, but also of geography and income. The data reveal that extreme heat hits low-income neighbourhoods and areas with ageing building stock particularly hard, where households have fewer resources to insulate their homes or protect themselves from solar radiation.

This detailed assessment highlights why general climate policies for entire cities are no longer enough. The researchers have identified urban hotspots that require targeted intervention. The major challenge now facing local authorities, architects and urban planners is how to take effective action in the specific buildings and public spaces identified on risk maps. Diagnosing the problem is essential, but the real test lies in putting solutions into practice.

From diagnosis to materials innovation

For urban planning and adaptation strategies to move beyond statements of intent on paper, construction materials and methods must be transformed at their source. This is where materials science and applied technology become a first line of defence, offering solutions that are already available today.

In contrast to the traditional urban model, dominated by cement-based surfaces that absorb and store heat, advanced technological solutions such as those developed by PhotoKrete offer a new approach: giving buildings and urban spaces an inherent cooling capacity through photonic mortar.

This integrated technology acts directly on the urban envelope—pavements, roofs and façades—to help counter the urban heat island effect through three key mechanisms:

• Surface cooling: It limits heat absorption in pavements, façades and roofs by reflecting solar radiation, preventing these materials from acting as heat stores or radiating heat back into the streets.
• Protection for vulnerable neighbourhoods: It can be used to upgrade buildings in areas identified by risk maps as particularly exposed, helping improve indoor comfort in homes where residents have fewer resources.
• Reduced energy dependence: It provides cooling directly through the building material itself, helping reduce reliance on air conditioning and lower artificial cooling costs.

The roadmap for tackling the extreme heat affecting our cities lies in combining the scientific precision of multiscale analysis, such as that carried out by EHU, with the use of smart materials. Only then can we move towards cities where a postcode no longer determines a person’s vulnerability to extreme heat, and urban environments become more liveable and better prepared for the challenges of a changing climate.

Would you like to explore how these solutions could be applied to your next urban planning or building project? Contact our team for technical advice at www.pkphotokrete.com.

About the OLADAPT project: The vulnerability to heatwaves varies significantly from one urban area to another.