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Prism Tower/400 Park Avenue South

Christian de Portzamparc

Project Name

Prism Tower/400 Park Avenue South


400 Park Avenue South

Project Status



430,556 sq. feet

Construction Cost




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Text by Joseph Giovannini

In his Yale University lectures, architecture historian Vincent Scully used to extoll Frank Lloyd Wright’s Guggenheim Museum for busting up the New York grid with a geometry that breaks the phalanx of apartment buildings along Fifth Avenue: The building’s spiraling drum spins in a vortex that breaks apart Manhattan’s tight parade of buildings. America’s champion of organic architecture, a declared enemy of the box, released the grip of the orthogonal city. 

Two avenues east, on Park Avenue South, and a half century later, Christian de Portzamparc, Hon. FAIA, similarly disrupted the constricting grid of the city, but with another geometry. The French architect deployed an elongated 40-story prism whose crystalline forms establish a zone of their own that open up the street wall, breaking free of the dense pack of right-angled, brick-faced buildings. As with the Guggenheim, 400 Park Avenue South disrupts the urban pack with an exceptional, and exceptionally beautiful, surprise: a tall, sheer rock crystal of glass. The entire shaft of the elegant new landmark is iconic, not just the crown. The Prism, as it is called, contributes not just to the skyline but to the bodyline of buildings, Yosemite’s West Face transposed to Manhattan.

For all its éclat on its corner at Park Avenue and East 28th Street, de Portzamparc says the $400 million building grew from the inside out. Manhattan is, of course, famous for the spectacular views from its skyscrapers, but the dirty little secret of many buildings is that apartments sharing party walls have no windows, and those facing rear have no views other than nearby buildings just on the other side of mean backyard setbacks: residents live with their blinds drawn for privacy.

Portzamparc configured an L-shaped building to match the shape of the site, but he kept the ends clear of the adjoining buildings, where he extruded pavilions with windows oblique to the street. The angled windows capture longer views and more light. The architect configured the two legs of the L as intersecting volumes, and he detailed the joints between the intersecting volumes and adjacent pavilions with deep reveals whose shadows separate, and profile, the adjacent prisms. 

Rather than stepping back the mass to comply with zoning laws intended to bring light down to the street, de Portzamparc simply inclined the leading edges of the prisms to open a path of travel for sunlight. “Instead of using terraced setbacks to respond to code, I fragmented and angled the façade,” says the architect. He detailed the tower so that its spandrels and awning windows form continuous surfaces whose visual unity supports the profile of each shard, highlighting their shapes and the separation between them. The eye looks to the knife-like corners and finds that the blades are crisp and sharp.

De Portzamparc designed the tower in 2003, building on the critical and popular success of his previous work, the LVMH Tower, completed in 1999 in Manhattan, where he first fragmented a street façade as a way of satisfying code setback requirements. Averaging the push and pull of the façade’s fragments achieves the same degree of slope as terraced setbacks. On Park Avenue South, he proved that the same idea applies at a much larger scale.

 In a feedback loop, the irregularity of the perimeter, caused by the search for views and light, rebounded back to the floor plans, where the multiplicity of privileged corners in the distinct volumes created opportunities for unique apartment configurations: the building is not a box, nor are the apartments. New York–based Handel Architects, architect of record, designed the rental apartments on the lower 22 floors; Stephen Alton Architect, also a local firm, did the condominiums above. The architects were able to leverage the irregularity of the perimeter into highly differentiated plans that escape the cookie-cutter predictability of cuboidal buildings. Sociologically, the variety of plans—from studios to four bedrooms, varying in size as the leading edges lean—guarantees a varied population among the renters and condominium owners. The basement in the tower is lavishly equipped with a large gym, 60-foot lap pool, screening room, community room, playroom, kitchen, and conference room. A store along Park Avenue and a restaurant along East 28th Street, with a subway entrance in between, will animate the street when completed.

After a dozen years of delay, few changes were made. “I was gratified that the design remained valid and dynamic after so long,” says de Portzamparc. His interpretation of a complex, angular language that started appearing internationally in the 1980s remains fresh because of the clarity of an idea and a form expressed so robustly. The fragmented shapes and tapering lines deny the mass of what appears to be an explosion of crystal. The angular tower, with the elegantly detailed curtain wall, startles the eye in the predictable right-angled world around it. 400 Park Avenue South is exceptional within in its context, and exceptional within its tradition as an uncompromised statement.

During planning commission hearings about zoning changes for the project, a former city council member, Margarita Lopez, said she happened to be reading Dante, and in an unexpected paean to the building, she said she liked the way the sunlight would follow the architectural lines into the Stygian depths of the subway station at the foot of the tower. Conversely, in the upward direction, the oblique lines, some converging, force perspective, creating the perceptual illusion of accelerated form: the building is visually dynamic because it plays perspectival tricks as old as the Renaissance, but in a vertical rather than horizontal direction.

The various community and city agencies voted in favor of the project, even giving it bonus square footage, because members felt it made a positive contribution to the neighborhood and the skyline. Their approvals proved right.  

Project Credits
Project: Prism Tower/400 Park Avenue South, New York
Client: Equity Residential and Toll Brothers City Living
Architect: Atelier Christian de Portzamparc, Paris—Christian de Portzamparc, Hon. FAIA; Frederic Binet, Bruno Durbecq (architect assistants)
Executive Architect: Handel Architects, New York—Blake Middleton, FAIA (partner); Jessica Wetters, AIA, Emil Stojakovic, AIA (project architects)
Interior Designer: Handel Architects (apartments); Stephen Alton Architect, New York (condominiums)
Mechanical and Electrical Engineer: Cosentini Associates
Structural Engineer: Desimone Consulting Engineers
Civil and Geotechnical Engineer: Langan Engineering
Construction Manager: Lend Lease
Façades: Gordon H. Smith Corp.
Landscape Architect: W Architecture and Landscape Architecture
Lighting Designer: Bliss Fasman
Zoning Consultant: Development Consulting Services
Size: 430,556 square feet 

Cost: $400 million

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