The construction sector faces major transformation: less waste, lower emissions, more re-use. This is precisely where the study by Hans Ignacio Scholz, Research Associate at the Glass Competence Center of TU Darmstadt, kicks in. He examines how disused insulation glass can be directly incorporated into new products. The approach promises to provide enormous CO₂ savings – but there are still some obstacles to overcome to achieve widespread application.
Your study shows that disused insulation glass can be processed into high-performance laminated toughened glass. What role could this approach play for circularity in the construction sector?
Hans Ignacio Scholz: In the circularity context we speak of “repurpose” – this means using old components in new products. The aim is to reduce the consumption of natural resources, avoid waste and cut energy consumption.
Our study shows that the production of laminated toughened glass (LTG) using reclaimed glass sheets can save up to 80% CO₂ emissions – compared to LTG made from new glass sheets.
Against the backdrop of the European Green Deal and the EU Action Plan for the Circular Economy, this is an important contribution to reducing greenhouse-gas emissions in the construction industry. In addition, the reuse of insulation glass proves a more attractive alternative than classic recycling: because for the latter the glass cullet is molten first and then repurposed.
This does save energy compared to primary glass production but still produces additional waste.
Where do you currently see the greatest obstacles: in approval, logistics or adoption in construction?
Hans Ignacio Scholz: On the one hand, we lack the science base for approval: so far there are too few studies on the natural ageing of architectural glass. We have to prove that even old/obsolete glass – meaning glass that has been in use for decades already – fulfils the same quality and standard requirements as new glass.
Also needed is the political framework to accelerate the process. Tax incentives for “re-use” glass might be feasible, making this option more attractive and affordable for building owners. People might view these products a bit like organic produce in the food sector: not necessarily lower-cost but with a clear added value for the environment.
And finally, it is about logistics and construction practices. Dismantling and transport require a skilled workforce to avoid damage to the glass sheets. However, the whole thing will only make commercial sense once there are new business models that can compete with today‘s market prices. At the end of the day, it will above all be a question of cost.
