Calwer Passage
The Calwer Passage is located at the geographical centre of the state capital Stuttgart. For the redesign, the upper sections of a building from the 1970s were replaced by a new building with up to seven storeys of intensive greenery. The basement floors remained partially intact.
Green Facade for a Healthy Microclimate
The listed “glass barrel” of the passage facing Calwer Platz was integrated into the new building complex. The ground floor contains retail space and gastronomy, the basement floors form part of the Stadtmitte S-Bahn stop. The upper floors contain flats and office space.

Sustainability Concept with Green Facade
The facade areas are generously glazed and equipped with solar and glare protection. In front of it is the construction for building greenery along the opaque parapet bands. The planted horizontal bands are arranged one above the other on each storey. Some of them are connected to each other by vertical climbing aids. The irrigation and drainage of the approximately 2,000 large-format planters is integrated into the construction and also serves as access for the gardeners for maintenance.
This green facade is an important component of the design’s sustainability concept.
Podcast episode on “green facades
Intensive Green Roofs
The green facades are complemented by the intensive greening of the roofs using a wide variety of woody plants and tree species. In the Calwer Passage, the greening of façades and roofs creates a breathing urban space with a natural, healthy climate. During heavy rainfall, the greenery and substrate build-up acts as a temporary reservoir for the water masses. In addition, the plants can also reduce local fine dust concentrations and counteract the otherwise observed summer overheating of heavily built-up areas (the so-called “urban heat island” effect). The local microclimate is thus decisively improved.
Architecture
Ingenhoven Architects, Düsseldorf/Germany
Tennigkeit Architekten, Stuttgart/Germany
Planning time
2017 – 2020
Construction time
2018 – 2022
Services by Werner Sobek
- Facade engineering, inc. green facades (WP 2 – 8)
- Planning for the building services engineering and the irrigation systems required for the green facades
- High-level access planning for the facades
- Sustainability consultancy and DGNB certification
Client
Piëch Holding, Stuttgart/Germany
Rendering
Ingenhoven Associates, Düsseldorf/Germany
Photography
Kilian Bishop, Stuttgart/Germany
In the interview “Stuttgart is getting greener: The new Calwer Passage “, our colleague Florian Starz explains the most frequently asked questions about the construction, plant selection and challenges of the green facade of the Calwer Passage. Florian Starz was responsible for the project’s facade planning.
