System modeling of the barriers impeding reuse and recycling as part of the transition to circular construction with a focus on Berlin

The reuse and recycling of construction products are crucial strategies within the transition to circular economy in the construction sector. The aim of this study is to identify and analyze the main barriers influencing construction product reuse and recycling in the Berlin region and understand the connections among these barriers as a system. The system is fed with data obtained through interviews with key stakeholders active in the construction sector in the study region, which allows us to identify twelve significant barriers. Among the most prominent barriers are the high effort needed to comply with certifications and legislation and the low-level demand and low acceptance of recycled and reused construction products. Three important causal loops revealing direct and indirect connections among barriers are identified. These findings result in policy recommendations targeting regional relevant leverage points in the system, such as the implementation of end-of-waste criteria, the requirement of considering recycled and reused construction products in tenders and process digitalization.