Circular Industrialized Construction

Abstract

The construction industry accounts for 40% of material resource use and produces 40% of global waste. Within this industry, various solutions have been attempted to lower the environmental impact. Two of these concepts are the circular economy (CE) and industrialized construction (IC). CE refers to an approach that embraces circular supply chains as opposed to a “take-make-dispose” system. IC can be defined as a “construction technique in which components are manufactured in a controlled environment, transported, positioned and assembled into a structure with minimal additional site works”.
The IC approach offers three potentials to overcome several barriers compared to circularity in traditional buildings. (1) The IC nature of supply chain integration supports the notion of shared responsibility for a CE. (2) IC is characterized by a longer planning phase to coordinate assembly on-site providing an opportunity to plan for disassembly in order to recover the material in the future. (3) IC focusses on standardization of prefabricated parts which supports adaptability and flexibility, thereby anticipating future modifications. Research on the combination of the Circular Economy and Industrialized Construction remains very limited. This thesis identifies opportunities to accelerate the integration of CE principles in industrialized construction methods within a Swiss context. This research is structured along three parts: (1) a literature review to assess the main developments of circular industrialized construction. (2) A conceptual framework combining two qualitative frameworks – the Strategic Niche Management and the Multi-level Perspective is developed to study and compare case studies demonstrating circular IC (UMAR unit, ICEhouse and ECO Solar Houses) including the external factors facilitating or impeding this development. (3) Finally, a list of recommendations providing a pathway for scaling up circular IC in Switzerland is presented. Data is collected through literature review, desk research and semi- structured interviews with stakeholders directly involved in the projects and industry experts. The findings indicate that five circular strategies should be present and work together to increase the circularity potential of IC: circular materials, product as a service, product lifetime extension, sharing platforms and resource recovery. At the start of a project, the use of comprehensive material database and increased documentation is crucial to make informed decisions about retaining value at a building’s end-of-life phase. Building layers should be separated and specifically for a building with many different materials and components, a higher level of pre-assembly is favored to increase control of construction to achieve higher reuse of recovered materials. Business models need to be reconfigured by extending ownership of components and modules. Transformation in design is recommended by incorporating standardization and design for disassembly practices to enable future reuse. The study showed that the establishment of demonstrator projects is key to facilitate the development of the circular IC niche. Specific network characteristics need to be present: a facilitator providing financial capital and flexibility and a diverse multidisciplinary team with stakeholders who are involved early in the process to create a common circular mindset. Finally, the initator(s) will have to demonstrate leadership through sharing the mission and vision explicitly to attract more stakeholders, who in turn can supply resources. Governmental involvement through VAT reductions on secondary raw materials and the provision of financial incentives is crucial. A regulatory framework for the input of construction materials will be essential and needs to be developed. In support of such a framework, a secondary raw material marketplace, outcomes of research programs and certification labels may be developed. By adopting these measures, circular industrialized construction can be scaled up through new projects, and in doing so contribute to a more sustainable construction industry.