Straubenhardt (Enzkreis), May 16, 2022. The inauguration of the circulatory fire station in Straubenhardt is imminent: After three years of construction, a building opens its doors on May 21, which is unparalleled not only in the “Musterländle” region. The building is one of the first in Germany in the public sector to be built by the Baden-Württemberg municipality in the Enz district according to the “Cradle to Cradle” cycle principle.

This is a recyclable process according to which building materials are designed in such a way that they can be reused and reused in a new building project when converted or dismantled. Baden-Württemberg's Minister-President Winfried Kretschmann has already recognized the municipality as a sustainable role model for other municipalities for this pioneering work. The Stuttgart-based architecture firm wulf architekten gmbh planned and implemented the sustainable lighthouse project with support from the environmental consulting institute EPEA GmbH, a subsidiary of the consulting firm Drees & Sommer SE.

The “Cradle to Cradle” principle (C2C® for short) is essentially about nothing less than using raw materials for products, processes and buildings in such a way that they are either retained in the same quality or can be returned to the biological cycle in a completely degradable way. The fire station built according to this principle is thus transformed into a valuable raw material depot and material warehouse. Straubenhardt is also striving for this type of construction for new commercial and building construction projects in the future.

In doing so, the municipality is countering the construction industry's hunger for resources, which consumes around 40 percent of the world's raw materials. Recycling is usually only possible in inferior form — for example as filling material. As a “Cradle to Cradle” model municipality and certified Fairtrade municipality, the Baden-Württemberg municipality of Straubenhardt proves that there is another way: “We are setting a good example for other cities and municipalities in building in a resource-saving way,” says Mayor Helge Viehweg. “In the new fire station, we are already implementing the future measures planned by the Federal Government to promote the circular economy in the construction sector. For example, the digital building resource pass is being used in a public building for the first time. ”

The tension between architecture and sustainability

“At Wulf Architekten, we have been familiar with the planning of sustainable buildings, including those with technically sophisticated and complex programming,” says architect and managing partner Ingmar Menzer. “Nevertheless, we faced many challenges during the course of the project, as circular construction is still new territory for many players in the industry.” The architectural standard was high, because it was not only necessary to use healthy materials, but also to keep the sealed floor space as small as possible. The solution was to layer the different functions of the building on top of each other and to use the hillside location of the property.

“This stacking is clearly visible from the outside, creating the characteristic and identity-creating appearance of the fire station,” says Menzer. The massive base contains all rooms necessary for use and the hall for the fire trucks. The open mezzanine is used as a parking lot and for events. Office, community and training rooms are arranged in the wooden structure raised above it. The white expanded metal façade makes the building appear homogeneous. “Straubenhardt's fire station is proof that a circular design, the lowest possible use of materials and an appealing, modern architecture are no contradiction,” summarizes Menzer.

Climate driving license for buildings

Overall, pure materials such as wood, metal and concrete are used in the new fire station building in Straubenhardt. Together with architects and specialist planners, the environmental consulting institute EPEA GmbH selected almost 250 individual materials from the approximately 80 components and tested them, among other things, for their material health, separability, recyclability and CO2 emissions during production and transport.

The team led by engineer Daniela Schneider supervised the architectural competition, ensured the recyclability of the materials and also created a resource material passport — known as a “Building Circularity Passport.” “It is a type of climate license for buildings, which transparently shows how CO2-intensive and sustainable the building material used is,” explains the engineer. “When the building is converted or dismantled at the end of its useful life, important information is available as to what it is made of and in what quantities various building materials are available. ”

Materials tested for pollutants and recyclability

Schneider's team, in close consultation with the architects, first carried out a component analysis: This includes examining the materials for their structural chemical composition, pollutants and possible emissions to indoor air. There are hardly any additional layers to cover wall, floor and ceiling surfaces in the building. This ensures an uncomplicated dismantling process. The majority of the interior walls consist of pure reinforced concrete or wood. Only in the kitchen or in the shower cubicles do tiled surfaces provide splash protection. The building also requires largely no adhesives or assembly foams: For example, many elements have been bolted together so that the materials remain easily separable. Thanks to this approach, downcycling no longer takes place.

Healthy spaces for citizens

In order to streamline the organizations, the municipality is accommodating six former fire department departments from the sub-locations in the new building. The youth fire department also finds premises here, which are available for holiday courses and public events, among other things. “The fire station is not only sustainable, the social aspect also plays an important role. This is an important building for the entire community. We ensure that citizens can stay in a healthy home,” says Mayor Helge Viehweg.