How Can Material Stock Studies Assist the Implementation of the Circular Economy in Cities?

Abstract

City and regional planners have recently started exploring a circular approach to urban development. Meanwhile, industrial ecologists have been designing and refining methodologies to quantify and locate material flows and stocks within systems. This Perspective explores to which extent material stock studies can contribute to urban circularity, focusing on the built environment. We conducted a critical literature review of material stock studies that claim they contribute to circular cities. We classified each article according to a matrix we developed leveraging existing circular built environment frameworks of urban planning, architecture, and civil engineering and included the terminology of material stock studies. We found that, out of 271 studies, only 132 provided information that could be relevant to the implementation of circular cities, albeit to vastly different degrees of effectiveness. Of these 132, only 26 reported their results in a spatially explicit manner, which is fundamental to the effective actuation of circular city strategies. We argue that future research should strive to provide spatial data, avoid being siloed, and increase engagement with other sociopolitical fields to address the different needs of the relevant stakeholders for urban circularity.

The complexity and interconnectedness of circular cities and the circular economy for sustainability

“…The 'circular city' was heavily imbued under the circular economy in both Leximancer and VOSviewer analysis results, indicating a close relatedness between the two concepts. While the circular economy's primary focus was the industry sector (Camilleri, 2020;Wuyts et al, 2022), it quickly evolved to include cities (EMF, 2019), as indicated in our results. The next impactful concept closely related to the 'circular city' and circular economy was 'urban metabolism'.…”

“…Waste management was the second most focused area for circular economy and circular cities. While from the economic perspective, considering the whole life cycle is the goal (Wuyts et al, 2022), the results indicate that the focus lies within the final phases instead. Particularly for cities, we identified the inclusion of focusing on 'water', 'energy', 'food' and 'material flows' and their 'treatment'.…”

Australia's circular economy metrics and indicators

“…Building smaller houses or using materials more efficiently are other potential strategies, but the complexity of specific engineering solutions like concrete printing may pose substantial challenges (Batikha et al., 2022). Nevertheless, material efficiency can also encompass strategies like elongating building lifespans, substituting problematic materials, and reusing building components (Zhong et al., 2022) supported by policies promoting secondary construction material hubs (Wuyts et al., 2022).…”

A framework for semi-automated creation of Building Information Models for existing buildings

“…The idea of circularity although is not new, it is in the last years gaining attention as a measure towards the mitigation of environmental impact connected to human activities [5]. Comprehensive understanding and documentation of the existing building stock on a city, regional, or national scale can contribute to the development of urban mining-, reuse scenarios and strategies [6]. Therefore, material stock studies are a crucial component of the transition into a circular economy at the city level.…”