Every year many thousands of tons of window glass from building demolition and refurbishment ends up as aggregate or in landfill. Thankfully British Glass and their European equivalents have come together on a €9 million project to change all that. It is common knowledge that we need to recycle more as the waste we produce as a small island nation is astronomical, so any endeavour towards lowering waste in construction projects should be trumpeted from the roof tops.
British Glass believe that more glass from buildings (windows and architectural panels from refurbishment and demolition projects) could be recycled back into glass. As their CEO, Dave Dalton, explains “Finding other uses for waste glass prevents glass from going to landfill and creates secondary markets for this extraordinary material.” It’s also investigating the addition of waste glass to eco-cement and eco-concrete.
While all this seems a worthy goal, people do not appreciate just how specialised different glass types are, explains the experts at the architectural glass company Vitrine Systems. There are types of smart glass, sometimes called switchable glass, which adjust according to the external environment. They can control heat or light in buildings; while others are designed for structural integrity. You would not use the same glass in your wine bottle as you do in buildings like the Louvre or The Shard. Not only do they have to ensure that those inside the building are not roasting during the summer and freezing in winter; it also has to be incredibly resilient. Just imagine what would happen if just one panel on The Shard or any significant glass clad structure failed? So they need to be specially treated and created to ensure their safety. It is unlikely that these specialist types of glass can be turned into “Cullet” (furnace ready recycled glass) however the old glass from the standard British Victorian terrace almost certainly could be.
Certainly there are environments where recycled glass can be used more effectively. Pure glass, from drinks bottles, is 100% recyclable and can be recycled endlessly without loss in quality or purity. Recycled glass can be substituted for up to 95% of raw materials in this environment.
However, other kinds of glass like windows, ovenware, or crystal, are manufactured through a different process. If these materials are introduced into the glass container manufacturing process, they can cause production problems and defective containers. This recovered glass is then used for non-food glass products, like floor tiles, aggregates or ground down for sand blasting compounds.
So, although it’s technically possible to recycle glass from buildings, up to now it has been difficult to prevent contamination and make the system financially viable. The new €9 million European venture makes a typically bold and worthy claim ‘Fostering industrial symbiosis for a sustainable resource intensive industry across the extended construction value chain.’ Clear as glass, right? The 26 pan-European companies involved do have good and worthy intentions though. If we could recycle more of the glass from construction waste, it could save us around 246kg of CO2 emissions which might go some way to undoing the damage caused by a certain car company’s fudged figures. Watch this space.