Every year, 35,000 tonnes of flat glass are deposited in Sweden – one of the construction sector's most energy-intensive materials. Although the material can be recycled almost indefinitely, over 90 percent goes directly to landfill. The production of new flat glass requires large amounts of energy and virgin silica sand – a critical and finite resource. At the same time, the requirements for traceability, climate reporting and circular materials in construction projects are increasing.
The solution: an industrial cycle for flat glass
To take the next step from ambition to implementation, Akademiska Hus, together with Ragn-Sells and Saint-Gobain, has put circular principles into practice by establishing a functioning process for recycling flat glass – from dismantling to new windows.
In Örebro, Ragn-Sells has built the country's first circular recycling plant for flat glass. It can receive up to 10 tonnes of glass per hour, which covers all of Sweden's and parts of Norway's needs. Here, the glass is separated, crushed and quality assured using advanced optical technology that ensures the purity of the glass. It is then sent to Saint-Gobain's plant in Germany to become a new raw material – their most low-carbon window glass.
Results:
- Up to 53 percent lower climate impact compared to virgin glass
- Approximately 30 percent lower energy consumption
- Reduced need for virgin silica sand
Photo: Anders Bobert
Akademiska Hus shows the way
In order for circular windows to become a reality, the glass must first be collected from demolitions and renovations. Collection is the key to a functioning cycle. At Akademiska Hus, we have a goal of reaching net zero in all our operations by 2040, and we are now developing a long-term roadmap for circularity. It will identify and prioritise measures for increased resource efficiency, economic benefits and reduced climate impact. In this work, the Teknikhöjden property plays an important role.
In connection with the dismantling of the building, the project was used as an innovation object to explore new ways of working and business models for reuse and recycling – primarily of heavy building components such as concrete and natural stone, but now also flat glass.
"We must make circular solutions become standard in the construction sector. The fact that we, as property owners, can actively feed high-quality raw materials into new material flows shows that recycling is not only possible – it is a business strategic necessity to future-proof the industry and secure the supply of window glass in the future. If we continue to consume virgin silica sand at today's rate, we will have no sand left in 60 years," says Jörgen Olofsson, project manager at Akademiska Hus and the company's responsible for the dismantling of flat glass in Teknikhöjden.
To enable the work, a digital copy of the building was developed, together with Ragn-Sells. It made it possible to take stock of the number of windows even before dismantling, identify its type, and measure geometry, volume and weight. Through the digital copy, handling and logistics could also be planned. It took just over ten minutes to identify 10.2 tonnes of windows for flat glass recycling.
In Teknikhöjden, a total of 135 windows with a total weight of 10.2 tonnes will be dismantled. The glass is disposed of as waste, but instead of going to landfill, it is recycled into new raw material and becomes part of the glass's circular cycle – an important move from linear waste management to a system where waste becomes a valuable resource.
"Akademiska Hus shows what is possible when property owners take an active role in the climate transition. We have the technology, logistics and climate benefits, now we need volumes to scale up. Together, we can make circular recycling of flat glass a natural part of the construction sector's value chain. Sustainable, traceable and scalable," says Camilla Sonnentheil, Business Development Manager at Ragn-Sells.
Clear climate benefits and business benefits in the same solution
Circular flat glass provides significant climate and resource benefits. A life cycle analysis from 2050 Consulting shows that a fully circular glass process reduces climate impact by 53 percent. In addition, about 30 percent energy is saved compared to new production and the need for virgin silica sand is greatly reduced.
"For us, recycled flat glass is an important piece of the puzzle in our journey towards net zero emissions. We have high quality requirements in our production, but through our collaboration with Ragn-Sells, we have access to a recycled raw material that lives up to our high standards. This is circularity in practice," says Moritz Feid, Head of Circular Economy at Saint-Gobain.
With stricter climate requirements, new EU directives for sustainability reporting (CSRD) and increased pressure on resource efficiency, the need for circular material solutions has never been clearer. By integrating recycled glass into the projects, property owners and construction companies can improve their climate and sustainability reporting, meet requirements from environmental classification systems such as the Swedish Green Building Council, the Nordic Swan Ecolabel and BREEAM, and strengthen their brand as a responsible and future-oriented player. which in the long run leads to better cost-efficiency in construction projects.
From one-off initiatives to new industry standards
Within the framework of the collaboration, the flat glass is handled through a cohesive process – from inventory and collection to logistics, quality assurance and recycling – in collaboration with Ragn-Sells and Saint-Gobain, where the recycled glass is passed on to window manufacturers.
Akademiska Hus is one of the first property owners to lift glass recycling out of the traditional procurement and turn it into an innovation procurement together with Ragn-Sells. However, in order for the solution to move from single initiatives to established industry practice, it is required:
- Early decisions in project planning and procurement
- Increased collaboration between property owners, contractors and manufacturers
- Clear climate goals and circular material strategies that guide the choices in each project phase
"This is about more than recycling. It is about creating a new infrastructure for circular material flows, where traceability, scalability and quality are central elements. We have shown that it works and that the capacity is there. Now we hope that more property owners, developers and contractors will follow suit," concludes Camilla Sonnentheil.
