Sustainable collaboration and circular innovation

In the final phase of the project in Utrecht Overvecht, the FMP phase, the finishing touches are being put on an ambitious renovation project of as many as 1,800 homes. There is a strong focus on sustainability, with particular attention to circular solutions. Kömmerling Nederland supplies the plastic frame profiles from which Schipper Kozijnen then makes ready-made facade elements - including frames.

A notable aspect of this latest phase is the use of recycled materials, a first within this project. The glass previously harvested from the previous phase "STROYS" will be reused for the new window frames. The panels from this project will also be harvested to be reused in future projects. In addition, the recycling of old plastic window frames has been underway for some time through participation in the Kömmerling recycling program. Kömmerling collects residual lengths, saw pieces and end-of-life window frames from all customers. These are then processed into granulate, from which high-quality profiles are again made.

A crucial factor in the success of this large-scale renovation project was the consistent collaboration within the project team throughout all phases. This allowed continuous improvements to be made, with a focus in the final phase on optimizing circular solutions and practices. Head of Sales Business Market Jappe Dekker of Schipper Kozijnen emphasizes the importance of this approach: "Circularity is becoming increasingly important and is feasible in every project, provided that the entire chain is open to this approach, including architect and client."

Streamlined collaboration

Even the coating process of the profiles at Kömmerling was coordinated with Schipper Kozijnen and the architect. "We have been working with Schipper Kozijnen for forty years, and outside of this project also with DOOR Architects," says Remco van Overdijk, account manager at Kömmerling. The coating process of the PVC profiles produced in Berlin and Pirmasens (D), which are sold under the name K-VISION, was optimized for Overvecht in collaboration, to create more choice in color variations. In the THEMA phase, for example, the special color RAL 7030 (stone gray) was developed. "Instead of film, in Overvecht we use a color coating produced by vacuum technology." This gives the window frames a matte look and feel. In addition, this system offers several additional benefits, such as reduced heat absorption and a dirt-repellent layer.

Aesthetic and durable

Kömmerling works a lot with architects, who generally like sleek or invisible applications. The cold feet about plastic have long since disappeared, says Van Overdijk. "If you compare our profiles to those of a car window, you see no difference. Extruding is our core business. The prejudice is based on frame systems from decades ago." For example, the frame profiles for Overvecht have depth effects. "We get questions today mainly about longevity. The old frame systems are reprocessed as granulate without downgrading and reused to produce new profiles." Doubling the lifespan is the result. Dekker: "If circularity is possible in the housing market, it is possible - with the right volumes - everywhere. Also in terms of insulation value, the system used more than meets the requirements. We work with minimal sawing loss, and when it comes to plastic window frames always with Kömmerling. The porches in Overvecht were measured separately for all 1,800 apartment houses prior to the installation of the elements, and the materialization and color scheme were readjusted for each phase."

Sustainability Standards

Prior to assembly of the façade elements, the frames glazed with HR++ glass will be installed at final manufacturer Prefab Building Systems. With the final phase commissioned in March 2024, the project launched in 2019 is nearing completion. The renovated flats have not only acquired a fresh and friendly appearance, but also meet the highest sustainability standards. Van Overdijk: "This method is not only relevant for this project, but also has potential for countless renovation projects in the future. Circular construction will only become more important." Dekker: "The addition of harvesting glass for the new window frames in the FMP phase has been a challenge, we managed to apply improvements in each of the five phases. It is a pity that the project is almost completed, when you see how and how much we have innovated and to what extent the smooth cooperation, also with the manufacturer of the facade elements, has been fine-tuned. Innovations that we will of course also use in subsequent projects." Van Overdijk: "There are still countless renovation projects waiting for this type of sustainable system, and circular construction will only become more important in the future."