Kassel, Germany, May 19, 2025. Dilapidated buildings, shortage of school places and increasing student numbers – the situation in German schools is critical in many places. The city of Kassel is now setting a new standard by building a highly modern school building for Waldau Open School (OSW), which operates on progressive educational principles. Not only will the new complex offer optimal conditions for 950 students and 90 teachers, but it will also be a lively neighborhood meeting place. The planned facilities include a youth and district library and a youth center, and these facilities can also be used by all local residents. The new building will be designed as a showcase example for circular construction. For this reason, the city of Kassel closely collaborates with the Environmental Protection Encouragement Agency, EPEA, a subsidiary of Stuttgart-based consulting firm Drees & Sommer SE.
“Our target is to create a building that complies with the highest requirements in terms of pedagogy, function and sustainability,” explains Michaela Jordan, project head at GWG Projektentwicklung GmbH. The design comes from C.F. Møller Architects, a renowned Danish architectural firm with a focus on energy-efficient structures, sustainable materials and flexible room concepts.
Rescuing Raw Materials instead of Wasting Resources
A special highlight of the new building is its adaptable structure. With its modular façades and its skeleton frame construction with a timber load-bearing structure, the building can easily be altered or extended at a later date without wasting valuable resources. EPEA has been part of the Drees & Sommer Group for five years. The environment consulting firm takes part in the development of recyclable construction and building products for the real estate economy and industrial sector. Interdisciplinary teams – formed by environmental scientists, chemists, architects, building engineers and materials specialists – provide advice to companies and the public sector on the transformation of a linear into a circular economy. The client list includes industrial companies, such as Würth and Schüco, and cities, such as Heidelberg and Kassel.
Primarily regenerative raw materials and recyclable materials were used in the construction of the school. EPEA project manager Antonia Birkholz comments “We focus particularly on sustainable resources such as timber and clay which not only protect the environment, but also improve the indoor climate. Joints and connections which can be separated after use, as well as prefabricated construction modules, enable us to create a flexible building that complies with the demands of the future and at the same time satisfies all sustainability requirements.“
Passports Please: Circularity Passports for Buildings
To ensure the seamless subsequent use of the materials, the main priority is to provide transparency. This can be achieved with materials passports which document components and structures up to the smallest detail. In the last eight years, ENPA has already issued more than 100 of these circularity passports for buildings. They document exactly which types of material are used in the building, including volumes and quantities, to what extent materials come from renewable resources – such as timber – or recycling, and whether materials can be reused at the end of their lifecycle. The identification includes all materials used in a building. A high score can be achieved with materials that can be reused and dismantled, for example, and there are deductions for products that are inseparably fused together.
A very close look is taken at the carbon dioxide foodprint of the construction: it shows the emissions arising from the extraction of the raw materials, from product processing through the exchange of individual elements to the recycling of materials at the end of their life. OSW causes around 25 percent fewer gray emissions than traditional buildings thanks to the use of low-carbon materials. In conjunction with the building energy efficiency standard, emissions are reduced throughout the entire lifecycle.
Healthy Materials and Biodiversity as Key Elements
A central goal in the implementation of the school project is to create a healthy environment for the pupils of the school. The challenge is that many building products still contain harmful substances which are detrimental both to the environment and the human body. For this reason, the selection process for the materials in the new building not only takes strict threshold values into account, but it also focuses on selecting products which are beneficial for human health. For example, clay surfaces can not only neutralize unpleasant odors, but they can also bind contaminants and thus render them harmless.
In addition to a healthy indoor atmosphere, Waldau Open School also provides ecological highlights in its exterior. Green roofs improve the microclimate and create habitats for native plants and animals. Michaela Jordan says: “We are not just building a school, we actively participate in shaping the future of our neighborhood. The new building will offer a healthy learning environment from which nature and people will benefit.”
More pictures can be found in the media library of C.F. Møller Renders | Download images | 1
