Circular Economic Modelling: Barriers and opportunities in turning circular within the construction sector

¹ CWARE ApS., BLOXHUB, Copenhagen, Denmark
² ETH Zurich, Chair of Sustainable Construction, Department Civil, Environmental and Geomatic Engineering, Switzerland

^* Corresponding author: bgha@cware.eu

Abstract

Drawing on the findings and insights from two on-going research projects WOOL2LOOP and URBCON, we have developed a model to assess the circular economic potential while using secondary raw materials (SRMs) to substitute OPC (Ordinary Portland cement) partly or fully within the building materials and construction industry. Applying our Circular Economy model (CEM), we have assessed the business case at each step of the value circle from sourcing, pre-treatment, production, and sales. At each step we describe the baseline, intervention, costs, and benefit flows identified as a result of introducing intervention. Furthermore, we assess the externalities and identify potential barriers preventing the business case to un-fold. While WOOL2LOOP focus on the usage of mineral wool waste, URBCON has a broader scope on different industrial residuals and waste streams suitable to produce geopolymer cement. Our analysis shows that pre-treatment costs of the various SRMs, future supply and geographical availability of SRMs, constitute critical factors to the overall business case for using SRMs. On the demand side, the main critical factors identified relate to building standards and resistance to change within the construction sector itself. However, there are also very strong macro trends encouraging for different reasons the various stakeholders to shift towards climate-neutral production and consumption. The paper concludes by discussing different scenarios for the evolution of new value chains and industry structures likely to happen in a ‘perfect’ circular economy reality.