The Reuse Potential of Hundreds of Insulating Glass Units in Buildings

A Case Study in The Netherlands

Authors

DOI:

https://doi.org/10.47982/cgc.10.688

Published

2026-06-15

Issue

Vol. 10 (2026): Challenging Glass 10

Section

Glass Circularity

License

Copyright (c) 2026 Esther Geboes, Ed Melet, Pieter Bons, Waldo Galle, Niels De Temmerman, Elke van Nieuwenhuijzen

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Abstract

Reuse of entire insulating glass units (IGUs) is a high-level circular strategy to reduce material use, energy demand, and CO2 emissions from manufacturing, but remains little studied. This study explores the technical reuse potential of 930 argon-filled double glazed IGUs in 43 Dutch buildings, using residual argon gas concentration as screening criteria for reuse. It assesses associations with IGU age, orientation, building, and assembler, and reviews the scalability and practicality of the proposed screening method. The reuse potential is explored through three perspectives: an availability-driven approach, a performance-driven threshold (T85) of ≥85% argon based on gas-fill requirements in EN1279, and a condition-driven threshold (T80) of >80% reflecting allowable argon diffusion over a 25-year service life as assumed by EN1279. Data was collected using spacer codes and the Sparklike Laser Portable. Results show that 54% of tested IGUs meet T85 and 75% meet T80. Although trends were observed for age, orientation, building, and assembler, none proved reliable as complementary pre-screening criteria for reuse. The proposed in-situ screening method is time-consuming; simplifying the protocol, integrating emissivity measurements, U-value calculation, and standardizing spacer codes can improve efficiency and reuse decision-making. When applying T80 for reuse, monitoring edge seal performance over time is advised. Further research should balance economic and environmental considerations (e.g. operational energy loss) for both product-level requirements and building-level reuse requirements. 

Author Biographies

  • Ed Melet, Amsterdam University of Applied Sciences

    Ed Melet is Associate Professor of Circular Building in the Climate Resilient City research group at the Amsterdam University of Applied Sciences.
    Ed received his PhD from TU Delft in 2017 with Activerende Gevels (Activating Facades), a study on buildings that encourage behavioural change. Since then, he has led the Circular Building research line, first as a senior lecturer and now as an associate professor. Melet and his team are investigating how buildings and the built environment can be made more circular in order to reduce their environmental impact. Before joining AUAS in 2002, Ed was a technology editor/researcher at trade magazine the Architect. He has also published in national and international journals, such as Bouwen met Staal, Cement, Business Innovation, Korean Architecture, Domus, Deutsche Bauzeitung, Dax, Renovatie & Restoratie and Detail in Architecture.

  • Waldo Galle, Vrije Universiteit Brussel

    Waldo Galle is a part-time assistant professor at Vrije Universiteit Brussel (VUB) and associate researcher for the Flemish Institute for Technological Research (VITO). As a member of the research groups VUB Architectural Engineering and Business Technology and Operations, he studies the financial and socio-technical feasibility of a circular construction economy. He questions which opportunities the transition towards that economy raises, which constraints it creates, and how the architectural practice changes together with it.
    Familiar with methods for system analysis, interactive redesign and reflexive monitoring, Waldo explores also more strategic opportunities and hurdles, such as the changing business model of architectural firms, or the absorptive capacity of small and large construction companies. As a member of the VITO Nexus, Waldo applies these methods also in support of various international projects on the circular economy and related regional policies, for example in collaboration with EIT Climate-KIC.

  • Niels De Temmerman, Vrije Universiteit Brussel

    Prof. dr. ir. arch. Niels De Temmerman (°1977) is a member of the Research Lab for Architectural Engineering (AE-LAB) of the Vrije Universiteit Brussel, Belgium and is chair of the research group ‘TRANSFORM – Transformable Structures for Sustainable Development’. Currently, he co-chairs the Structural Morphology Group (WG 15) of the IASS (International Association for Shell and Spatial Structures). He is an architectural engineer (2002) with a PhD on deployable structures (2007). His main expertise entails the design and analysis of transformable structures (deployable structures and kit-of-parts systems) for architectural applications. He is supervisor of a large number of ongoing and finished PhD research projects in the field of sustainable building.

  • Elke van Nieuwenhuijzen, Amsterdam University of Applied Sciences

    Elke van Nieuwenhuijzen is a sustainability advisor with a background in fungal-based wood finishes and circular construction. She obtained her PhD in 2018 through a joint position at the Westerdijk Fungal Biodiversity Institute and Eindhoven University of Technology, focusing on natural fungal-based wood finishes. From 2022 to 2024, she worked at the Amsterdam University of Applied Sciences on circular building practices, with a particular emphasis on the reuse of insulating glass. Today, she works as an advisor at Woonkwartier, supporting sustainable transitions in the built environment.