Calculation and evaluation of circularity indicators for the built environment using the case studies of UMAR and Madaster

• Published in: Journal of cleaner production 2020-01, Vol.243, p.118482, Article 118482
• Main Authors: Heisel, Felix, Rau-Oberhuber, Sabine
• Format: Article
• Language: English
• Subjects: Circular economy; Circularity indicator; Material bank; Material passport; Recycling; Urban mining
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2019.118482

Understanding buildings as material depots radically changes the way resources need to be managed within the construction industry and the built environment. Similar to warehousing, buildings, cities and regions will have to keep track and anticipate the stocks and flows of materials, needing to document and communicate (at the right moment) which materials in what quantities and qualities become available for re-use or recycling where and at what time in the future. This paper describes the process of documenting materials and products utilized in the construction of the Urban Mining and Recycling (UMAR) unit within the Madaster platform. UMAR is a fully circular residential unit of Empa NEST created from secondary resources and designed as a material depot for future constructions. Madaster is an online platform, which generates and registers materials passports and calculates a Circularity Indicator for their construction, use, and end-of-life phases. The results of the calculations show that the UMAR unit is 96% circular. Constructed from 95% non-virgin and rapidly renewable materials, the unit has a utility rate of 98% and 92% of its materials are prepared to return into pure-type material cycles at the unit’s end of life. In combination, these two case studies provide a unique opportunity to evaluate the capabilities of materials passports and the Madaster Circularity Indicator to document material stocks and flows within a circular built environment, and to assess the potential of circularity indicators as a design tool supporting the transition towards a circular construction industry. The continuous development of tools and systems for material cadastres undoubtedly represents a key prerequisite for the implementation of a paradigm shift towards a functioning circular construction industry.