The central square of the Schoenberg neighborhood, in Fribourg, is a textbook example of an urban heat island. It is mostly made of concrete and stone, with little shade, greenery or water in sight. In August, the team led by Séréna Vanbutsele measured the temperature on some surfaces of the square. At the height of the heat wave, one reading showed a surface reaching more than 70°C.
‘It is a busy square’ mentions Séréna, pointing to the afterschool building on one side and the childcare on the other. ‘But locals just pass through, they never stay here.’ The high temperatures and lack of adequate infrastructure are to blame. Microclimate simulations by ETH colleagues led by Aytaç Kubilay and Jan Carmeliet confirmed what Séréna already suspected: the square is one of the hottest areas in the city. Without intervention, it will become unlivable as heatwaves become more frequent and intense in the future.
As part of the activities of SWICE WP5, Séréna’s team collaborated with REPER, the association working on social and cultural activities with local inhabitants. They set up the Living Lab Schoenberg (also known as Projet O’Frais), that aims to build temporary installations to cool down the square, while also increasing its appeal and fostering social bonds. During two weeks in August, Projet O’Frais gathered local children, teenagers and mothers to work on this goal.
Led by Agnès Collaud, the team came up with a vision for turning the square into a cool archipelago, an inviting place where heat doesn’t need to be unpleasant. The intergenerational team started by painting an island on the concrete ground, using bright light-yellow paint. Next, the team designed and built a temporary terrace to provide shade and a place to sit down for locals. The structure allows for younger children to test their climbing skills. The team also painted an exterior wall of a central elevator shaft in white, with the goal of painting a light-colored mural on top of it.
‘The techniques we use are well-known’ says Séréna. ‘Light-colored paint, shading, vegetation, and water features.’ She points to the large shading tarp that a local woman is stitching together, made from an old hot air balloon. A large part of the work is being carried out by locals. Séréna hopes that this active participation can lead to empowerment. Some of the teenagers involved in the project were struggling to find an apprenticeship. The project’s main partners, REPER and the TRANSFORM Institute of HEIA-FR, ensured that these teenagers would be able to leverage this experience on their CVs.
On the other side of the square, two cameras have been set up by the team, to assess the impact of the project. They count the number of users of the square and the time each of them spends in it, a way of measuring the improvement in quality of this public space. The city of Fribourg has shown interest in the process. Three of its representatives are discussing how to replicate this experience elsewhere in Fribourg.
Next year, Projet O’Frais will try to improve the installations by adding vegetation and a water feature, and extending the project to other parts of the neighborhood. The team also hopes to convince the city and private owners to start a discussion on improving the quality of outdoor spaces in Schoenberg. Everyone agrees that the project should evolve and adapt according to feedback and needs from the local community. And when the heatwave hits in the summer of 2026, everyone is hoping that the archipelago of Schoenberg stays as cool as possible.