How Circular is an Italian Apartment Building? Testing of a Whole-Building Circularity Indicator

Circular economy (CE), focused on closing the material loops, turns out to be relevant in the building industry to improve the construction process and reduce waste. Assessing the circular performance of buildings reveals the current level of achievement and future areas of improvement, hence aiding in transitioning from a linear to a CE based construction industry. However, this can be very complex, especially due to absence of a universally accepted Circularity Assessment Framework. Bearing that, a comprehensive CE assessment tool called Whole-Building Circularity Indicator (WBCI) is being developed at Engineering Department of University of Campania. This study tests and validates the first version of the freshly released WBCI using an existing apartment building in Southern Italy as a case study. The data is collected through building documents (detailed drawings, specifications) and site visits, and then modelled in BIM to perform a rigorous analysis. The results show that the apartment building does not perform well in circularity and scores very low (0.274). Excessive use of virgin materials, linear design approach, poor adaptability and disassembly potential after the end of life are the leading causes for this low score. The space plan turns out to be the most circular system among different building layers. The validation also uncovers the positives and negatives of the tested model. Finally, the study recommends practical strategies to improve the circular performance of residential buildings. With these advantages, this paper contributes to the much-anticipated debate on the measurement of CE in the building industry and can help construction practitioners estimate how advanced they are in the process of transition from linear to circular