Direct reuse and recycling of materials can significantly reduce the net environmental impact of the global construction sector. The feasibility of reuse and recyclability of building systems is affected by the materials used and the interfaces between constituent components. Yet there is a lack of quantitative methods for assessing the environmental benefits of alternative recovery strategies for multi-component and multi-material systems over the building lifetime. In this work, a novel assessment method was developed to enable a systematic and quantitative evaluation of the transient environmental reclamation potential (RP). The reclamation potential is a measure of the ability to disassemble and reuse recovered building systems at their end-of-life and is influenced by the constituent components and the interfaces between components. The proposed method accounts for the technical service lifetimes of components, including performance degradation over time, and can thus inform decisions on the most suitable recovery route for new and existing designs. The graphical outputs from the RP assessment are a network diagram which highlights the system components and connections between components, and an RP-graph which illustrates the embodied environmental impact and reclamation potential over time of alternative reuse/recycling strategies. The methodology is demonstrated on a glazed double-skin façade where the influence of component service lifetimes and replacements over time is quantified in terms of embodied energy and embodied carbon. The outcomes of the assessment can guide decision-making in design for disassembly (DfD) strategies and/or aid in the identification of high-value material recovery strategies at the end-of-life stage.@en

This article has been amended to correct the in-text figure and table referencing and to provide clarification in Table 1 that automotive flat glass production does not take place in the UK. The Supplementary Information has been updated to correct reported units and clarify production processes. The original article has been corrected.

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Reuse and high-value recycling have a pivotal role to play in reducing waste and minimising carbon emissions in the built environment. Design strategies for such recovery methods have yet to be fully established in the façade industry. Meanwhile, stringent regulations, aimed at reducing operational carbon emissions of buildings and improving other performance criteria such as occupant safety, have stimulated the use of more complex façade systems that incorporate multiple functions. Other areas of the façade life cycle, such as embodied carbon and high-value material recovery, are rarely considered at the early design stage. This study adopts a mixed-method approach of data collection, to investigate the key challenges and opportunities associated with promoting high-value recovery options for façade products, as perceived by stakeholders in the façade supply-chain. Data was initially collected through an online survey completed by 69 stakeholders from across the façade knowledge/supply-chain. This was followed by 29 semi-structured interviews with selected survey respondents. It emerged that the advancement of circular design strategies is dependent on: increased awareness and quantification of the environmental value of circular design; cross-supply-chain buy-in on developments in take-back infrastructure including greater support for demolition contractors; and advancements in technological separation methods specific to façade components. Enhanced communication between stakeholders - notably between clients, facade contractors and material processors - acceptability criteria and product availability; and more holistic legislation based on whole life cycle emissions, to avoid the over-emphasis on operational efficiency, appear as vital requisites to increasing material efficiency. Finally, we illustrate where stakeholder priorities related to reuse converge and diverge, and thus we identify strategies for levering these factors to minimise environmental impact and optimise economic value in the façade sector.

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