In Risch-Rotkreuz, the 100.000m2 “Suurstoffi” area is currently being developed into a new mixed use district by Zug Estates AG. As part of this, a project for a high-rise was put out to tender – a high-rise with a green, planted facade.
The winning project by Ramser Schmid Architects and Lorenz Eugster Landschaftsarchitektur und Staedtebau GmbH is a 70m high-rise with office and commercial space on the first floors and 85 condominiums with 1.5 to 5.5 rooms on the remaining floors. It is designed as a garden-high-rise with green balconies, a roof terrace with various seating areas and a summer green tree roof.
The term “garden high-rise” seems contradictory at first, but it is the central design idea in the spirit of Le Corbusier, who once dreamed of stacking country houses. The balconies not only offer space for a few potted plants but, as stacked gardens, become an essential part of the feeling of space and an attitude to life. The windows of the apartments are laid out as a panorama – in the foreground the garden balcony, in the background the landscape of the pre Alps. The boundaries between inside and outside dissolve.
Greening facades – technical basics
The first four floors are intended for commercial use without green facades, so the “vertical garden” does not begin until the fifth floor. Sufficiently large troughs had to be provided along the facade for all plants as well as special technical solutions to ensure an optimal supply of water and nutrients in the appropriate quality and quantity. There were also special requirements for the substrate: It had to be structurally stable, have sufficient water holding capacity and at the same time only cause moderate loads. The decision was made in favor of backwater irrigation. With this solution, there is permanent water at the bottom of the trough, the plant can access the vital element at any time.
The irrigation concept provides that the individual troughs are supplied with water in a cascade from top to bottom. Pipes carry the water from trough to trough. The water is taken from a rainwater tank, which is located in the basement and is fed from the surrounding roofs. This water is pumped up through a pressure pipe and distributed to the various downpipes. If necessary, tap water can be added.
There are three areas with plant troughs: in front of apartments, in niches and on the roof terrace. Two to three troughs are assigned to each apartment, and a green niche is assigned to each access corridor and the stairwell on each floor. These provide the green light in the corridors and also allow a view of the sky. The roof terrace with its large troughs is designed as a green tree roof.
There are a total of eight plant arrangements – four facing south and four facing north. All arrangements have a similar structure: solitary wood, “hedge column”, small shrubs, climbers, perennials and onions. 140 solitary trees, 200 hedge plants, 350 shrubs, 1200 climbing plants and 14,000 perennials in over 50 species were planted. A declared aim of this planting concept was to make the different seasons visible and tangible. In spring it blooms, in summer it shines green and in autumn red tones dominate.
In addition to the flora, the fauna is desirable and a planned part of the planting concept. The choice of plants should ensure different habitats and food sources for insects and birds. Acer opalus and Parrotia persica are examples of forage plants for butterflies and bees.
What makes this project special?
The building is a built vision. The vision of stacked gardens in the form of a high-rise. The technical challenges and their solutions shift the horizon of what is technologically possible in the field of facade greening today. The union of fauna and flora in their unique diversity with the facade, with each individual apartment, enables a completely new attitude towards life – life in a garden – in a high-rise building.
Architecture offices involved in the design: Ramser Schmid Architekten
Project location: Hochhaus Aglaya, Suurstoffi 6343 Risch-Rotkreuz, Schweiz
Design year: 2016
Year Built: 2018 – 2021
Project description: The Garden – High-rise Aglaya