Perspectives on Environment & Sustainability
Circular Construction Industry in Switzerland
The construction industry is currently facing a major challenge: consistently transitioning from a linear value chain to a truly circular economy. Our buildings, roads, and other infrastructure represent enormous reservoirs of raw materials, yet far too little of these resources are returned to the cycle during demolition and renovation.
At the recent specialist conference on the “Circular Construction Industry” at the Bern University of Applied Sciences (BFH), experts provided an impressive overview of the current state of circular approaches in the construction sector and demonstrated that significant challenges, but also substantial opportunities, lie ahead in the transformation toward sustainable and circular construction.
Building and infrastructure construction are particularly resource-intensive sectors. Every year, tens of millions of tons of concrete are incorporated into these structures. At the same time, several million cubic meters of mineral demolition materials are generated annually, with volumes continuing to rise. Circularity deficits were highlighted for materials such as asphalt and gypsum. Although large quantities of asphalt are recovered from road construction, they frequently end up in landfills due to a lack of specialized treatment facilities. Gypsum has been imported for decades. Gypsum waste remains in Switzerland and is often disposed of in waste incineration plants or landfills. Recycling it into cement concrete would be possible but requires extensive processing.
The circularity of construction materials and related construction waste is further complicated by the presence of PFAS contaminants. Since the 1970s these substances have increasingly been used in construction applications, for example in sealants, coatings, and sprayed concrete. They are extremely persistent and may lead to quality issues in recycled materials. Without clear regulations, a kind of “PFAS anxiety” could result in increased landfilling of demolition materials, which would be exactly the opposite of the intended goal. This would be particularly problematic because PFAS contaminants can easily leach from landfilled construction waste, contributing to their diffuse spread into water bodies. From the perspective of achieving closed material loops, the challenges posed by increasing material flows, limited landfill capacities, and complex contaminants in construction materials and mixed demolition waste (PFAS, PCBs, asbestos) should be addressed without delay.
To improve the circularity of construction materials, several approaches were highlighted, including the integration of circularity into planning processes and the concept of “Design for Disassembly.” Digital tools such as Building Information Modeling (BIM), product-related data systems such as the Digital Product Passport (DPP), environmental assessment methods such as Life Cycle Assessments (LCA), and expanded quality criteria in procurement processes were also discussed. Rather than focusing solely on costs, these criteria aim to create clearer framework conditions that promote circular economy principles throughout existing value chains. In addition, participants explained how circular economy strategies can be embedded at the organizational level.
Positive examples were presented in the field of metal and steel recycling. Metals and steel can be recycled without any loss of quality, minimizing downcycling and making closed-loop systems easier to achieve. However, due to the dynamics between demand, recycling rates, and costs, as well as the low prices of primary materials resulting from externalized environmental costs, dependence on imported steel remains significant. As a result, the associated high levels of embodied energy and environmental impacts also persist.
Through the use of scrap metal and expanded metal and steel recycling, material cycles within Switzerland should be kept as closed as possible. Metals and steel are regarded as valuable raw materials. Their recycling is far more energy- and CO₂-efficient than the production of primary steel and aluminum. To successfully recover all metals from demolition projects, carefully planned demolition logistics are required, and recycling must be integrated as an essential part of the value chain. Achieving this will require appropriate framework conditions and incentives, for example through market-based environmental instruments.
Construction companies are also acting as pioneers and drivers of the circular economy. Practical examples demonstrated how circular thinking can be implemented in real-world projects. Life Cycle Assessments showed, for example, that only around 10% of CO₂ emissions are generated by construction machinery, whereas more than 80% originate from construction materials. This clearly indicates where circular economy measures should focus; namely on new circular building materials, corresponding demolition strategies, and networking and exchange platforms that facilitate the reuse of building components. Reliable measurement of indicators such as CO₂ emissions, resource consumption, and circularity was identified as a fundamental prerequisite. This was illustrated by the example of “Zirkulit Concrete,” which achieves a minimal environmental footprint. Accordingly, certification schemes for circular construction solutions can be developed.
Another example highlighted the remarkable innovative capacity of the concrete and asphalt industries. A cement and concrete manufacturer presented impressive reduction pathways showing that the use of alternative fuels, secondary raw materials, and CO₂ sequestration through carbonation could reduce production-related CO₂ emissions by up to 50%. A construction company developed an innovative asphalt production process using bio-based bitumen derived from cashew shell extract as a binding agent. This “bio-asphalt” has recently been applied in large-scale pilot projects on major roads. After 12 months of use, no noticeable difference compared to conventional asphalt could be observed. Applied research is also exploring bio-based construction materials aimed at reducing dependence on fossil resources. One example is “bio-bitumen” produced using the lignin-based binding agent “Green Binder.” Such innovations can replace fossil-based binders in asphalt production.
To successfully achieve the transition toward a circular economy in the construction sector, clear legal framework conditions and incentives are required, along with sufficient treatment and processing capacities and procurement systems whose award criteria incorporate environmental performance and circularity.
If Switzerland succeeds in managing its embedded resources within closed material cycles, it can significantly reduce CO₂ emissions, lessen its dependence on fossil resources, and serve as a global role model for how a resource-intensive construction sector can evolve toward truly sustainable construction.
Marco Semadeni, Dr. Sc. nat. ETH
March 14, 2026