The building sector is responsible for about one third of the total energy consumption and CO2 emissions in the Netherlands. For buildings, the windows are one of the most vulnerable components in terms of energy loss. The current windows in facades in the Netherlands mainly consist of low-quality systems that no longer meet energy performance standards. A large part of the existing glass of buildings have to be replaced. To accelerate the renovation processes and to reduce the environmental impact of the renovation, new circular window products need to be developed.

Within the SFEER project we are developing a circular window renovation concept. We develop a process to reuse old/used glass in new windows, and develop new smart window products to renovate and upgrade windows for optimal energy efficiency and comfort. The SFEER project is developing an innovative thermochromic and two types of smart retrofit window films. The renovation concept can lead to an annual energy saving of >30% and a saving of CO₂ emissions of 5.8 Mton per year in the Dutch built environment. The project will run from April 1, 2023 to March 31, 2027 and is being carried out by ClimAd Technology, TNO, Zuyd University of Applied Sciences, Eindhoven University of Technology,  Hemubo, GSF Glasgroep, OMT Solutions, Timmermans Hardglas, Ecomatters, Vlakglas Recycling Nederland, and “de Alliantie”. The main applicant is ClimAd Technology.

The SFEER project will deliver the following results: 1) A process to efficiently disassemble excisting windows, to clean the glass surface, to characterize it and to provide it with insulation coatings, to enable reuse of glass plates; 2) A new thermochromic PVB film for laminating recycled glass to make safety glass, including circular design for recycling and reuse of the functional material; 3) New photochromic and thremochrome retrofit window films, including circular design for recycling and reuse of the functional material. All products developed within the SFEER project are based on established technologies that have proven themselves at least on a laboratory scale and are now ready for scale-up and optimization. They will now be further developed to pilot scale with demonstration tests in a realistic environment.