Component-Based Model for Building Material Stock and Waste-Flow Characterization: A Case in the Île-de-France Region

Spatiotemporal tracking of building materials and their related environmental impacts

Urban development will increase the demand for new buildings expected to cause significant environmental impacts in the coming decades. Spatiotemporal prediction for new buildings, their typologies, resource quantities and types required for construction, and the associated impacts are crucial to effectively tackle strategies to reduce the related greenhouse gas emissions. Within the context of Denmark, this study establishes a prognosis of expected yearly embedded impacts across the country towards 2050 based on Business as Usual (frozen policy) trends. Through the Holt-Winters method's additive version, the study forecasted the future amount of building types in each Danish municipality. The embedded impacts disaggregated into building types, components, materials, and life cycle stages are calculated from the material intensity coefficients of real projects. Considering a 'business as usual' scenario, the prediction shows an increase in demand by 6.5 % for new gross floor areas compared to the number of current buildings constructed in the past years. The GHGs from the upstream processing of materials correspond to 7 % of current consumption-based yearly emissions in Denmark. To strive for sustainable development, the findings of the study help inform stakeholders in the built environment to better correlate the material mechanism 'supply-demand' for circularity and where efforts to minimize the impacts should be prioritized.

Challenges and Opportunities for Circular Economy Promotion in the Building Sector

The accelerated development of cities involves important inflows and outflows of resources. The construction sector is one of the main consumers of raw materials and producers of waste. Due to its quantity and potential for recovery, waste from the construction sector constitutes significant deposits and requires major action by bringing together different stakeholders to achieve the objectives of a circular economy. Consequently, it is crucial to understand the current knowledge of urban metabolism, deposits, and recovery practices. This article aims to investigate the role of local authorities in the planning of strategies to facilitate a circular economy; in particular, this article aims to answer how local authorities facilitate circular economy initiatives in the building sector and what opportunities and obstacles they encounter in the process. The strategy used for the study was to conduct semistructured interviews with those responsible for circular economy projects within local authorities that were pioneering circular economy projects in metropolitan France. The results highlight the importance of community involvement in the implementation of circular economy principles in the building sector. Thus, it is essential to identify the different stakeholders and their respective challenges to build an operational framework.