Promenade

The Jelmoli roof top may be considered a stepping-stone along an urban promenade of elevated green spaces in the city of Zurich. The department store has a comparable elevation and area to the close-by Old Botanical Garden and Lindenhof, and may therefore functionally be a similar ecological space. 

The envelope of the Jelmoli building are a light-containing shell: windows are blocked with wooden partition walls. This results in the most attractive spaces at the edge to the city being lost or misused. The project aims at making this room layer available again for new usages.

We connected the levels through cut-outs in the floor to create a passive air flow system through this outer shell. This benefits the whole building by providing a climatic buffer between the inside and outside. The cut outs are covered with a metal grid so that no floor space is lost. The wood partition walls are replaced with easy to install translucent polycarbonate wall sheets, which will allow daylight to enter the building, too. 

The width of the shell space and created two different kinds of rooms, a wide and a narrow room. The wide room is open to the public, and windows can be opened. The narrow room is accessible only for maintenance. The wide rooms build a promenade from ground level to the roof using the existing outer stair cases. The promenade encircles the building once by moving up one level each time a stair case is crossed.  

Both the shell space and the roof are inhabited by plants. On the roof we create an elevated green space for the city. We use the huge roof area to collect rain water and distribute into a net of pipes going through the shell. In the pipes we grow seedlings using hydroponic methods. We introduce a mycorhizzal nutrient system, which create a network between the roots and reduce the amount of artificial fertilizers. The seedlings grown in the pipes are eventually transferred to the roof or are distributed into other green spaces throughout the city. 

Looking at the city scale, we embed the Jelmoli into a larger network of natural habitats for plants and animals. Our green roof top and promenade becomes part of a larger promenade in the city between the Old botanical garden and the Lindenhof. The roof of the Jelmoli has about the same height as the old botanical garden and the Lindenhof, and constitutes as third space along this promenade of elevated green spaces in the city.

Collaboration with Philipp Eitel.