The renovation work at the residential centre of the Arbeiter-Samariter-Bund (ASB), Ortsverband Chemnitz und Umgebung e.V., in Rembrandtstraße in Chemnitz must be carried out with particular care. Because 32 people with severe physical disabilities currently live there in the 23 flats of house 2 of the facility, whose daily routine is to be disturbed as little as possible by the construction measures. This is not an easy task, because the project includes not only work on the façade but also the replacement of 205 old PVC windows with new thermally insulated plastic windows with triple glazing. During the removal and installation work, each window will be "enclosed" in a dust protection cabin in order to keep the occupied rooms as clean as possible. In the evening, the residents can already use their familiar living spaces again.
Careful with the environment
The client, the architectural office Claus Höhn, which was commissioned with the construction planning, and the Chemnitz-based handicraft company Liebert GmbH, are also prudent when it comes to disposing of the old building material. After removal, the old windows are not taken to the waste incineration plant, but are recycled in Thuringia at VEKA Umwelttechnik GmbH and then reused later as recycled windows in other places.
Exemplary building projects sought
At the same time, the Chemnitz construction project is taking part in the cross-state campaign "Best Practice for the Environment". In Saxony, Saxony-Anhalt and Thuringia, exemplary and sustainable building projects in which PVC building products are recycled will be identified and subsequently documented by the end of the year. The environmental campaign, which is actively supported by regional and national associations and companies, was initiated by Rewindo Fenster-Recycling-Service GmbH, Bonn, the Arbeitsgemeinschaft PVC-Bodenbelag Recycling (AgPR), Marl, and the Arbeitsgemeinschaft PVC und Umwelt e.V. (AGPU), Bonn.
Contribution to VinylPlus recycling targets
The Rewindo system has been active throughout Germany since 2002 and coordinates the material recycling of old PVC windows, roller shutters and doors in a closed material cycle. "In 2016, almost 30,000 tonnes of PVC granulate were recovered from old windows and recycled in the plants of the recycling partner companies cooperating with us. This corresponds to about 1.8 million window units," reported Rewindo Managing Director Michael Vetter during an on-site visit to the construction site. At the same time, his organisation is making an important contribution to achieving the recycling goals of the European PVC industry, which are defined in the Europe-wide sustainability programme of the "VinylPlus" community initiative.
Plastic windows with recyclate core
VEKA Umwelttechnik is one of the Rewindo partner companies and operates one of the largest and most modern window recycling plants in Europe. The windows from Chemnitz are transported there and enter the recycling process: the old PVC windows are first shredded and further reduced in size. Then they are separated by type into metal, rubber, glass residues and plastic in various processes. The latter is heated and pressed through a filter to separate out the last foreign particles. The pure PVC granulate recovered in the process is finally the starting material for new plastic fibre with a recycled core.
Recycling without loss of quality
"The old windows from Chemnitz do not have their lives behind them, but still have a long life ahead of them," Vetter explained. "Thanks to the high recyclability of PVC, the windows could even continue to serve for centuries. Scientific studies have shown that plastic windows with a service life of at least 30-40 years can be recycled and reused at least seven times without any loss of quality.