Circular IGUs: strategies for the technical evaluation of reclaimed window glazing

Abstract The glass industry is increasingly exploring remanufacturing as an alternative to the recycling of reclaimed glass cullet. Remanufacturing insulated glass units (IGUs) offers the potential to preserve valuable materials and their embodied carbon, accelerating the shift towards a circular and climate-neutral economy. However, technical uncertainties continue to impede the large-scale adoption of remanufactured IGUs. This study addresses these barriers by developing strategies for a comprehensive technical assessment of 30-year-old IGUs extracted from two office buildings. A range of standardized tests are conducted to evaluate critical factors influencing IGU reusability, including the overall visual surface quality, sealant and desiccant integrity, and surface flaws that may compromise glass strength. Additionally, the assessment considers the type of installation as well as relevant external factors that occur during the IGUs’ service life and could potentially affect their performance and viability for future applications. By establishing a technical evaluation framework aligned with European product standards, the findings aim to support best practices in IGU reuse and remanufacturing.