Sustainable window renovation in Lüneburg

Having grown up through salt production, Lüneburg is now looking to the future: with the "City of the Future Lüneburg 2030+" project, the Hanseatic city, together with Leuphana University and its citizens, is currently focussing in particular on sustainable urban development. The renovation of a total of 221 windows on an administrative building in the

Lüneburg city centre is not part of this project, but it fits in well: the building's energy balance is significantly improved by new plastic windows with triple glazing. The sustainability concept also plays a major role for the old windows: also made of plastic, they are not incinerated but recycled and reused later. The old windows are turned into new ones.

The environmentally friendly post-treatment was initiated by the window construction company Theodor Zink GmbH from Bergen. Zink is currently one of

nine premium partners and thus an active supporter of Rewindo GmbH, Fenster-Recycling-Service, which organises the recycling of old plastic windows, roller shutters and doors throughout Germany. For some time now, the company has also been supported in its sustainable endeavours by

by Bauplanung Saatze + Kleine GmbH, responsible for construction planning and management. "The project in Lüneburg is not the first of its kind that we have carried out with Zink. In our experience, plastic window recycling is also very well received by the building owners," says Managing Director Viola Kleine. In addition to environmental considerations

Financial aspects also played a role, as Philipp-Theodor Zink, Managing Director of Theodor Zink GmbH, reports: "We won the specific property through a public tender. The lower costs due to the

Recycling is the decisive competitive advantage over incineration."

The fact that the recycling of the old frames works so well in practice also has something to do with Lüneburg's past. The profiles are made from PVC, a material whose raw material base consists of over 50 per cent rock salt. In practice, the very good recyclability of PVC is utilised. In new window profiles, the recycled material can be found as a recycled core, which is coated on the outside with new PVC material. All the recognised advantages of PVC-U windows, such as durability, stability, low maintenance, a wide range of design options and high recyclability, are retained in the recycled profile. "The mechanical properties of the material even improve, as the PVC granulate obtained in the recycling process has a significantly improved homogeneity. The result is a true high-performance PVC that we call 'EcoPowerCore'," explains Jörn Schütte, Managing Director of Inoutic / Deceuninck GmbH from Bogen, profile manufacturer for the new Lüneburg windows and, as a Rewindo shareholder, also a staunch advocate of the recycling idea.

Technically high-quality, the recycled profiles also help to avoid harmful greenhouse gases. Every tonne of PVC recyclate used in profile production saves around 1.87 tonnes of CO2 compared to primary PVC. It is therefore not surprising that

In Lüneburg in particular, the new window profiles are also fitted with a recycled core. According to Schütte, this could be the case even more often: "One of our main systems, 'Prestige', was installed here. We can currently offer around sixty per cent of these profiles with EcoPowerCore. We want to increase this figure significantly in the future."

The old plastic windows from Lüneburg are then sent to the modern recycling plant of Rewindo's long-standing recycling partner Dekura GmbH in Höxter, Westphalia, where they are first shredded. Various processes are then used to separate glass waste, metals and plastic by type. While glass, metals and other materials are passed on to other recyclers for reprocessing, by far the largest fraction, PVC plastic, is recycled directly on site, where high-quality PVC granulate is produced for the manufacture of new windows.

The old Lüneburg windows are therefore looking to a new future.

(Photo:Rewindo)