Stuttgart, Germany
Located in the heart of Stuttgart, between Calwer Straße and Kronprinzstraße, the Calwer Passage by European Prize for Architecture Laureate Christoph Ingenhoven introduces lush greenery into the cityscape while preserving heritage-listed building sections.
The greening of façades and rooftops establishes a high-quality urban space with a natural, healthy climate.
The rich diversity of species generates a vibrant and ever-changing appearance.
Architecturally distinctive, this pioneering project significantly enhances the resilience and sustainability of the city.
The inauguration of one Germany’s most advanced shopping center in 1970 aligned with the comprehensive transformation of the Calwer Str. into a pedestrian zone.
The now completed green transformation upholds the original vision of urban rejuvenation, advancing the evolution of downtown revitalization.
The Calwer Passage project has been awarded a 2024 Green Good Design Award by The Chicago Athenaeum Museum of Architecture and Design and The European Centre for Architecture Art Design and Urban Studies.
Maintaining its structural heritage, the Calwer Passage continues to offer place for around 20 independent boutiques and owner-managed stores, fostering opportunities for local businesses in the heart of the city, otherwise dominated by large high-street retail chains.
Green roofs and facades serve as crucial contributors to the city’s microclimate by sequestering carbon dioxide, minimizing dust and noise, fostering biodiversity, and enhancing overall well-being.
Their paramount role lies in mitigating the urban heat island effect and facilitating rainwater retention, closing the gap in the water cycle and naturally preventing an overload of the public sewerage system.
The selection of greenery at the Calwer Passage aligns with the concept of a facade-integrated system featuring year-round active vegetation.
Plants are situated in containers along windowsills, forming evolving bands around the building.
Vertical climbing species link the floors.
The multifaceted green façade features alternating densities – moderate in front of the office windows to allow for optimal incident light without obstruction, intensifying in front of the stairwells.
The abundance of vegetative elements contributes to a dynamic and constantly evolving visual allure.
Diverse foliage, various fruit arrangements, and a range of flower shapes and colors offer year-round variety in both forms and hues.
The natural cycle of seasons further enhances this vibrant atmosphere.
A striking aspect and notable feature are nearly 40 large trees strategically planted on and around the building.
Among them, eleven—such as Black Pines, Pedunculate Oaks, Swedish Whitebeams, and Hornbeams—form a small mixed forest atop the roof: a distinctive silhouette, visible from afar.
The Calwer Passage’s refurbishment sparks vital discussions about the significance of urban greenery, emphasizing its invaluable role in city landscapes.
This innovative project challenges conventional urban developments, introducing vibrant, living greenery into an otherwise rigid and dull mineral environment.
It serves as a testament to the importance of bold initiatives in advancing architectural culture and sustaining meaningful discourse in urban planning.
Project: Calwer Passage Stuttgart
Architects: Ιngenhoven Associates GmbH
Design Team: Christoph Ingenhoven, Martin Reuter, Michael Rathgeb, Nina Schaffernoth, Victor Braun, Julian Blönningen, Bastian Müller, Jürgen Schreyer, Dariusz Szczygielski, Stefan Boenicke, and Thanh Dang
Phytotechnology: Dr. Strauch, Beuth Hochschule für Technik, Berlin, Fachbereich Life Sciences and Technology
Consultancy for Vegetation Ecology: Reif, Albert-Ludwigs-University, Freiburg, Professorship for Site Science and Vegetation Science
Clients: Calwer Passage and Ferdinand Piëch Holding GmbH
Photographers: HGEsch Photography | Kilian Bishop