The Berlin start-up "Green City Solutions (GCS)" has developed the world's first regenerative biotech filter with a measurable effect. The principle: special mosses absorb polluted air and convert its harmful ingredients into biomass and fresh air. In combination with sensors, intelligent ventilation, irrigation and software, the natural cleaning performance is increased and made usable and measurable.

In cooperation with Green City Solutions, yellow design was engaged to evaluate how the air-improving filter modules can be placed in inner-city areas in combination with small mobile phone transmission points using different scenarios.

Under the project name "CityTree", yellow design conceived a series of innovative street furniture designs that were developed with regard to the most important areas of public space and sensibly serve the different requirements within inner-city scenarios.

Wooden slats on the "moss side" reinforce the sustainable character of the street furniture and also provide the shading function. This ensures that the mosses are not exposed to harmful solar radiation, regardless of the installation location.

The layered structure with the centrally placed "wall disc" structures the body of the housing and serves to visually slim down the stela.

Made of translucent material, the inner layer can be used as a "light sword" and thus contributes to additionally enhancing the light situation at the installation site at night.