The Calder Gardens: Where Art, Architecture, and Nature Converge

Calder Gardens is not a conventional museum. From the beginning, the client sought a space that would offer a completely new, intimate, and ever-changing experience with the work of Alexander Calder. While the building is still tasked with the typical technical requirements of a traditional museum, it is conceived as a new type of place for engaging with art: a place that fosters an interplay between art, architecture, nature, people, and the surrounding city.

Philadelphia is Calder’s birth city and was the home of two previous generations of Calders who, as artists, left their own impressions on the city. Their sculptures can be found along the Benjamin Franklin Parkway, a boulevard that is a product of the 19^th century ‘city beautiful’ movement and is anchored by two of America’s most remarkable museums, the Philadelphia Museum of Art and the Barnes Foundation. Cutting across this Parkway is the sunken Vine Street Expressway, which, like many of its counterparts in other American cities, sliced through the existing city fabric in the mid-20th century. Calder Gardens is located at the intersection of these two significant streets.

The site of Calder Gardens is a flat, tapered piece of land located across the broad Parkway from the Rodin Museum and the Barnes Foundation. A highway offramp extends along its long southern edge while 22nd Street to the west and 21st Street to the east are primarily used as vehicular throughways. Despite its central location, the site is a vacant space with little obvious charm. The sound of the highway is always present, and few people have had reason to walk through the site. Creating a destination within this urban void was a central challenge for the project.

Form, color, and movement are the most apparent aspects in Calder’s art. When the concept for Calder Gardens was conceived, it sought to avoid rather than adopt these characteristics as possible design elements. Likewise, the design avoids the monumental architecture of the already impressive collection of museums that line the Benjamin Franklin Parkway. With these parameters in mind, it was decided that the face of this project should not be a building. Instead, it is a garden with a building within that reveals itself step by step as a series of distinct, heterotopic spaces.

In this unique commission in Philadelphia —from the site, to the open brief, to our design process—I focused on space over form, leading me to explore below-grade areas and discover the defining spaces of the structure.

Calder Gardens embodies a kind of ‘no-design’ architecture, allowing the works of art to express their diversity and ambiguity across numerous different spatial contexts. It’s a place where you can sit, wander, and observe, whether it’s nature or art, with the ease one has when one sits under a tree.
Jacques Herzog

The Wall and The Disc
When viewed from the Parkway, a tapered metal wall forms a backdrop to a public meadow-like garden. The wall reduces the sound of the highway and frames the garden, looking out towards the Parkway. Pathways from the northeast and northwest corners draw visitors through the garden towards a single central opening where a folded metal canopy covers a wood-lined entry area.

As visitors approach the entry, the architecture comes into view. A large central disc forms a plaza at the center and provides a roof to the galleries below. A geometrically pure circular ‘Sunken Garden’ towards the east and an elongated irregular ‘Vestige Garden’ to the west are carved into the ground on either side of the disc. They create protected outdoor spaces for Calder’s sculptures and bring light into the surrounding galleries. The intersection of the disc and the wall define the entry. A single window offers a glimpse to the galleries below.

The backside of the metal wall is covered with blackened wood, forming a simple barn-like building that faces the highway. The low building is only visible in the distance from this vantage point and does not draw attention to the project. It contains a few necessary staff spaces, a loading area and a small wood-lined lobby. The lobby is different from the typical large-scale spaces that define most museum entryways. It is domestic in scale and engages the individual as they begin their experience at Calder Gardens.

A Journey Through Light, Space, and Perspective
Visitors descend from the lobby to the galleries via a large stair that also serves as an auditorium, with a linear window offering views of the highway and city beyond. The ‘Highway Gallery’ is a mezzanine that allows viewing a Calder mobile from above, separated from the’ Tall Gallery’ by a beam and a narrow slot. From its mezzanine, a concrete-lined passage leads to the ground and the outer garden, also displaying Calder’s work. The stair reaches the main gallery, leading through the Tall Gallery to the ‘Open Plan Gallery’ below the disc, which is illuminated by natural light from a large window and connects to the Vestige Garden. An ‘Apse Gallery’ with curved walls offers distraction–free views of art. The Open Plan and Apse galleries showcase Calder’s works from multiple perspectives. A slot from the Open Plan Gallery reveals the ‘Sunken Garden’ and the ‘Curved Gallery’, which is an enclosed space with exposed concrete for controlled lighting, ideal for Calder’s paper works and light-sensitive sculptures, centred around the Sunken Garden, with a stabile against a curved wall.

Vestiges
The historical conditions shape the existing site surface, both in its interior plan geometry and garden layout. An offset of an adjacent water main creates a kinked boundary in the underground plan. Remnants of the old foundations, part of the pre-existing city grid before the Parkway was built, influence the design of the Vestige Garden. A ‘Quasi Gallery’ acts as a cave-like, covered outdoor area that bridges the highly controlled indoor gallery spaces and the open garden outside.

Together, these areas invite curators to showcase Calder’s diverse works in innovative and surprising ways. They serve as spaces for reflection and concentration, offering a journey through the environment rather than a traditional gallery experience. Calder Gardens is a dynamic space that unfolds as you enter.

Calder Gardens

Client: CP 2023, c/o Neubauer Family
Client Representative: Aegis Property Group

Architect: Herzog & de Meuron
Partners: Jacques Herzog, Pierre de Meuron, Jason Frantzen (Partner in Charge)
Project Team: Aurélien Caetano (Associate, Project Director), Mehmet Noyan (Associate, Project Director), Ninoslav Krgovic (Project Manager); Antoine Foehrenbacher, Julia Hejmanowska, Josh Helin, Neda Mostafavi, Daria Nikolaeva, Martin Jonathan Raub, Camilla Vespa, Rio Weber, Xin Yue Wang, Benjamin Muller;

PLANNING

Design Consultant: Herzog & de Meuron, Basel Ltd, Basel, Switzerland
Executive Architect: Ballinger, PA, USA

SPECIALIST / CONSULTING

Structural engineer: Ballinger, PA, USA
MEPF / AV / IT: Altieri Sebor Wieber, LLC, CT, USA

Landscape: Richard Herbert, NY, USA

Lighting: Flux Studio Ltd, MD, USA
Civil / Geotech: Pennoni, PA, USA
Concrete: Reginald Hough Associates, NY, USA
Waterproofing & Roofing: Simpson Gumpertz & Heger
Acoustics: Metropolitan Acoustics, PA, USA
Security: Cerami Associates, DC, USA
Signage: Karlssonwilker Inc., NY, USA
Vertical transportation: VDA, NJ, USA
Code: Jenson Hughes, MD, USA
Sustainability: Re:Vision Architecture, PA, USA
Specifications: Conspectus, MD, USA
Digital Rendering: Xaos GbmH, Basel, Switzerland
Digital Rendering: Aron Lorincz Ateliers, Budapest, Hungary
Digital Rendering: Bloomimages, New York, Inc
Sustainability: Re:Vision, PA, USA
Food Service: Corsi Associates

SPECIAL COLLABORATORS

Landscape Designer: Piet Oudolf, Hummelo, NL

Structure Consultant: Guy Nordenson and Associates, NY, USA
Concrete Consultant: Huber Straub AG, Basel, Switzerland
Concrete Restauration: Strotmann und Partner, Siegburg, Germany