Building a Sustainable City

All good things must come to an end, and as my turn in the ECOWAN Blog hotseat draws to a close, there’s no better time to look at what happens when our lovingly crafted buildings reach the end of their lifecycle.

While we place increased emphasis on creating the sustainable buildings of tomorrow, we need to ensure we’re thinking about the impact buildings will have on the environment once they’re no longer a proud part of a city’s skyline. This increasingly means factoring in long-term material sustainability right at the drawing board. Amongst other materials, we need to consider what happens when the glass that we manufacture for architects reaches the end of its life.

Waste glass (or cullet) can be recycled to create new glass. This results in less CO2 emissions than creating glass from scratch using raw materials

If processed carefully, glass can be fully recycled, enabling significant savings in raw materials and energy used in production. Melting glass is easier than melting the raw materials used to make it. With that in mind, it makes sense to reuse scrap glass (or ‘cullet’) and therefore reduce CO2 emissions compared to making new glass. Additionally, the raw materials used to make glass emit CO2 as they react in the glass-making process. Cutting the amount of ‘new’ glass being created reduces this CO2 burden too.

This has been understood in the industry for many years, and all good glassmakers recycle cullet from their own processes to reduce fuel consumption and CO2 emissions. Now, however, there is increasing pressure to recover glass from further down the supply chain, from glass processors, window manufacturers, installers and, eventually, from the companies who scrap the glazing at the end of its useful life.

Cullet can often be reprocessed into usable architectural glass products again

This end-of-life recycling can be more of a challenge. One can easily spend more energy collecting windows from a demolition site than is subsequently saved by recycling it. This means there are significant challenges we need to overcome to ensure such recycling has a real financial and environmental payback and is not just window dressing, if you’ll pardon the pun.

In order to achieve this, we need to work closely with architects and builders to ensure buildings can be demolished in a modular way, allowing end-of-life glass to be salvaged and reprocessed cost- and energy-efficiently. We need to establish systems that treat cullet as a valuable resource, keeping different types segregated and free from contamination, with the possibility to consolidate loads to make transport for recycling environmentally beneficial and cost effective. We all have a part to play in designing systems, processes and glazing components that make this a possibility.

This approach is already mandatory in vehicle scrapping as part of the End of Life Vehicles EU Directive (2000/53/EC). As a key member of trade body Glass for Europe, we will be actively looking for ways to implement a similar approach across the industry. This will ensure that architects don’t just leave a positive legacy in the buildings they create, but also in the overall sustainability of our cities.

Nick Shore is Sustainability Director for the NSG Group’s Building Products division. His remit is the creation and implementation of sustainability strategy to ensure it remains a core value at the heart of what the NSG Group does. The NSG Group is one of the world’s leading manufacturers of glass and glazing systems in three major business areas; Building Products, Automotive and Specialty Glass.

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