It occupies a prime location in the middle of the Bottrop pedestrian zone, but until recently it was not particularly attractive. With a wave-like, light gray facade, bright, attractive interior spaces and an ice cream parlor in the ground floor to draw in visitors, the commercial building dating back to the 1960s now barely resembles its former self. Much more important, however, is something not evident at first glance: the old-timer has been converted into a plus-energy building.