What does the transformation of a purely industrial site into an urban residential area entail for the open-space structures of the urban fragment between Leutschenbachstrasse and Hagenholzstrasse? Within the framework of a test planning procedure, we answered this question with the ‘Inner Garden‘ – a new open space typology that creates a fine network of passageways adapted to the site’s new use and complements the existing types of open space with a horticultural world.
The WolkenWerk project’s ‘Inner Garden’ takes its cue from its eastern perimeter. Here, an urban fragment of the forest is reframed as a strong identity-establishing open space. The design is characterised by the complexity of the interplay between space, time, image and ecology, creating a volumetric balance between structures and open space – between architectural mass and arboreal mass.
A reforestation strategy will, in the coming years, allow the tree volume to grow into a tree hall that has an important ecological and urban climate value. The shrub level, on the other hand, will adapt to the needs of inhabitants day to day and offer a horticultural component. An interplay of ecological succession and ‘instant gardening’ – of disorder and order.
The zone fronting Leutschenbachstrasse, the alleys paralleling the street, and the courtyard covered in climbing plants create an urban counterpoint and are formulated in mineral terms. Their asphalt and concrete surfaces as well as the specially designed steel gutters and bicycle stands cite the industrial past of the site.
The rainwater from the high-rise buildings flows through façade gutters onto the lower buildings, where it is retained and irrigates the roof gardens. The overflow spouts then lead the water into the garden at ground level, where it runs to the water collection basin via concrete and steel gutters. Thanks to evaporation and percolation, the strain on the sewage system is minimal. The variety of sections and materials of the banks of the water basin (generous flights of steps, inclined plane and planted areas) provides high utility and ecological value.
The design methodically makes use of the vertical layering of the forest. The tree layer refers to the dimensions of the built development and will evolve as a hall-like space. In contrast, the herbaceous and shrub layer react to the human scale and introduce horticultural conceptions and elements. From the very beginning and in collaboration with A. Heinrich, an expert plantsman, we developed a specific, climate-resistant urban forest in which the climax community, together with the shrub layer, provide seasonal accents within the ruderal landscape.
Architecture offices involved in the design:
ARGE Staufer Hasler Architekten / Von Ballmoos Architekten
Project location: Leutschenbachstrasse, CH-8050 Zurich, Switzerland
Design year: 2012-2016
Year Built: 2016-2020