A place which has been strongly shaped by Cologne’s recent history, a new open-air parkcafé in the centre of the Inner Greenbelt, the park designed by Schumacher in the first half of the twentieth century, is to be built. The building and the design of the open-air catering area is put into specific context of this historically significant place which is also the site of the “Trümmerberge”, the mountains of rubble, the ruins of the World War II Cologne that have been piled up there and turned into a serene landscape. The construction and the form of the café is developed out of these conditions.
Urbanistically the café is placed on axis with the railway underpass, through which all pedestrians and bicyclists move when approaching the site from the inner city. It is therefore easily visible and by means of its twin hills it marks a gatesituation to the Inner Greenbelt park - Cologne’s green lung - as a whole. A new design of the paths leads the visitor in between both hills, along the café down to the “Aachener Weiher” pond which forms the center of the park and which is adjoined by the Japanese Cultural Institute and the Museum for Far-Eastern Art on its other side.
The café consists of two steel containers that, having premanufactured, are transported and deposited on their future location in the park. Installed on their site, they are covered and buried by the rubble which have been excavated from the adjacent rubble-hills within the Inner Greenbelt. This process of excavation produces a depression or pit within the mountain, which is shaped with terraced seating in the form of a small amphitheatre. In connection with the café, a positive - negative relationship, an interaction and a condition of exchange is achieved. The construction of the building through a process of recycling. This excavation also exposes the history of the place, a place where the devastation of a completely ruined city lays buried underneath few centimeters of soil and grass. The significance of the place, holding the ruins of World War II are made visible, can be experienced and are put to use.
The café itself is structured functionally into two buildings as a separation of the toilets from the kitchen and food storage areas is desirable. All areas for cooking and for serving food and drinks are located in the northern mount. Its twin mount holds the spaces for the employees as well as all restrooms.
The excavation material, the historical rubble, are used constructively for the café are allow thereby for a very ecological and economical method of construction. The time of active building within the sensitive park environment can be reduced to very few days. The standardised containers, manufactured off-site obtain very thick exterior walls through the process of covering and burying, which gives the interior spaces a good climate especially throughout the summer months. The naturally / artificially raised hills are planted with grass, flowers and plants which produce ever changing colourful impressions throughout the year: white and snowcovered in winter, colourfully blossoming in spring, green and lush in summer and glowing red in fall.
The catering area is located on a gravel surface which is separated by a low curb from the grass of the park. The tables and chairs are individually protected by balloon-like constructions from the rain and sun. These “table-balloons” can be inflated like conventional balloons or can consist of two hardened plastic half-spheres. They are lit from within and in the night enwrap the café in a milky glow. Its form and construction achieves an affinity to the nearby Japanese cultural institute.