The reuse of glass: tackling the technical, environmental and logistical challenges

The reuse of materials has become a central concern in the transition toward a circular built environment. Among these materials, glass holds a unique position: it is technically durable and fully recyclable, yet its reuse remains rare. Most post-consumer glass from buildings is downcycled or landfilled, mainly due to technical and logistical barriers. Modern glazing systems, often bonded and complex, make recovery and disassembly difficult. Extending the life of glass through reuse, rather than recycling, could preserve both material value and embodied energy, yet uncertainty remains about whether existing glass can safely and efficiently be reincorporated into new building products and under what circumstances this would be environmentally beneficial. This research aims to evaluate the feasibility and limitations of reusing post-consumer glass in the building sector. By analysing the reuse potential of glass recovered from existing façades, the study investigates whether remanufacturing new insulating glass units (IGUs) from reclaimed panes can be achieved while ensuring technical reliability, logistical feasibility, and environmental benefits. The study was guided by six research questions, developed through a comprehensive review of scientific literature and analysis of current industry practices, trends, and needs. These questions are structured into three thematic areas: • Logistical: RQ1: How can glass components be collected and disassembled for reuse? RQ2: How can pre-demolition audits be tailored to support the collection and re-use of glass from buildings? RQ3: How can a traceability framework for glass be structured to facilitate its collection and reuse? • Technical: RQ4: To what degree can post-consumer glass qualify for reuse? RQ5: How can post-consumer glass be prepared to meet reuse requirements? • Environmental: RQ6: What are the environmental impacts of reusing glass compared to producing new glass? A mixed-method approach was adopted, combining experimental, analytical, and modelling techniques. Logistical studies explored the disassembly of IGUs through industrial trials and laboratory experiments, assessing manual and automated recovery methods. Four alternative logistical configurations were modelled to analyse the influence of facility location on transport and processing efficiency. Technical investigations included destructive and non-destructive mechanical tests on weathered glass samples, analysis of surface defects, sub-critical crack growth characterization, and evaluation of visual quality. Environmental analysis employed Life Cycle Assessment (LCA) to quantify the global warming potential of glass reuse compared to float glass production. Industrial disassembly trials demonstrated that automated systems efficiently separate glass panes while minimizing damage, whereas manual methods remain viable for small-scale operations. Co-location of disassembly within existing industrial sites was identified as the most efficient logistical configuration. A new framework for pre-demolition audits, integrating indices for disassembly, quality, and geography (Idfd, Iqualify, IGeo), was proposed to guide recovery planning. The findings show that high-quality weathered glass can achieve mechanical properties comparable to new glass, confirming its suitability for reuse. Edge treatment significantly improved strength, while sub-critical crack growth had limited influence. Environmental results indicate that reusing glass could reduce CO₂ emissions by up to thirty times compared to new production, although variability in real-world conditions requires further validation. This research provides guidance for industry stakeholders aiming to implement glass reuse and highlights the importance of linking micro-scale material performance with macro-scale logistical and environmental systems. Future research should focus on long-term performance testing of remanufactured IGUs, the reuse of coated and laminated glass, and the development of digital traceability systems to support transparent and reliable reuse processes. By addressing these areas, the reuse of glass can evolve from experimental practice to a scaled-up industrial framework.