The CBS Building, also known as Black Rock and 51W52, is a 38-story, tower at 51 West 52nd Street in the Midtown Manhattan neighborhood of New York City, New York, U.S. The building was constructed from 1961 to 1964 and was the only skyscraper designed by Eero Saarinen, who referred to the building as the "simplest skyscraper statement in New York". The interior spaces and furnishings were designed by Saarinen and, after his death, Florence Knoll Bassett. Built as the headquarters of the CBS broadcasting network, the building was also the headquarters of CBS Records (later Sony Music Entertainment) before the early 1990s.
The building is located on the eastern side of Sixth Avenue (Avenue of the Americas) between 52nd and 53rd streets, with its main entrances on the side streets. The "Black Rock" nickname is derived from the design of its facade, which consists of angled dark-gray granite piers alternating with dark-tinted glass. The facade was designed to make the building appear as a continuous slab. The building has a gross floor area of approximately . The building's superstructure is made of reinforced concrete, and steel beams are only used below ground; the concrete frame uses polyurethane insulation.
The design was finalized in 1961, and, despite Saarinen's death shortly afterward, construction started in 1962. The first employees moved into the building in late 1964 and it was completed the following year. The building initially served as the headquarters of CBS, which occupied all the above-ground space until the early 1990s, when it started leasing some stories to other tenants. The New York City Landmarks Preservation Commission designated the CBS Building as a city landmark in 1997. CBS attempted to sell the building twice between 1998 and 2001, and ViacomCBS again attempted to sell it in early 2020. Harbor Group International agreed to buy the structure in August 2021 and renovated it in 2023.
Site The CBS Building is at 51 West 52nd Street in the Midtown Manhattan neighborhood of New York City, New York, U.S. It is on the eastern side of Sixth Avenue (officially Avenue of the Americas) between 52nd and 53rd streets. The lot covers . The site has a frontage of on 52nd Street to the south, with a depth of between 52nd and 53rd streets. Nearby buildings include the Credit Lyonnais Building to the west, the New York Hilton Midtown to the northwest, 53W53 to the north, the Museum of Modern Art (MoMA) to the northeast, the 53rd Street Library and 21 Club to the east, and 75 Rockefeller Plaza to the southeast. The CBS Building stands directly above a New York City Subway tunnel connecting the Sixth Avenue and 53rd Street subway lines.; .
The building, developed for broadcasting company CBS, was designed to occupy only 60 percent of its site. It is three blocks north of Rockefeller Center, the headquarters of CBS's rival NBC.; ; . By the late 1950s, the midtown section of Sixth Avenue was being developed with office towers and hotels, including the Hilton hotel, the Time-Life Building, and the Equitable Building at 1285 Avenue of the Americas. The CBS Building had replaced five apartment buildings of four stories each, as well as a parking lot. CBS had acquired these structures in July 1960 from developer William Zeckendorf, who had been forced to sell the site to pay off increasing debts.
Architecture The CBS Building was designed by Eero Saarinen,; whose other designs ranged from the Gateway Arch, the General Motors Technical Center, and the Dulles International Airport Main Terminal to chairs for the Knoll company. The George A. Fuller Company was the general contractor for the project. Cosentini Associates was the mechanical engineer, while Paul Weidlinger was the structural engineer. Carson, Lundin & Shaw planned the interior layout of the building, designing the mechanical systems and interior partitions.; . Acoustical engineer Paul Veneklasen advised the firm on how to design different spaces in the building, based on varying acoustical requirements for different divisions. The furnishings were manufactured by Florence Knoll Bassett,; ; whom Saarinen had invited to the project shortly before his death in 1961. CBS's design director Lou Dorfsman and president Frank Stanton worked with Knoll to arrange the art in the building.
The building measures ; ; ; . and is tall, with 38 stories.; . It does not contain any setbacks on intermediate levels.; The building is recessed from the lot line on the north, west, and south and is recessed the same distance from an auxiliary building to the east.; ; . A separate structure with a loading area was provided east of the building, allowing the main structure to be a standalone slab.; . The building's massing evoked those of earlier standalone buildings, such as the unbuilt Tribune Tower design by Eero Saarinen's father Eliel, as well as Louis Sullivan's Guaranty Building. By contrast, the uniform treatment of the CBS Building's facade differed from these earlier designs, which were divided horizontally into three sections.
Plaza Surrounding the building is a plaza that is about below the Sixth Avenue sidewalk. It is reached by a flight of five steps from that street.; ; . The eastern part of the plaza is slightly lower, being six steps below 52nd Street and seven steps below 53rd Street. The plaza contains Canadian black granite pavers, the same material used in the facade.; . In contrast to the nearly contemporary Seagram Building, which had a decorative plaza with fountains and plants, the CBS Building's plaza was designed solely as a backdrop for the tower. Consequently, the plaza was not designed with seating, and there were no storefronts at plaza level. Before his death, Saarinen had written of his belief that a tower should stand as a solitary mass, detached from shorter buildings.;
At the time of the building's construction, New York City planners were considering enacting the 1961 Zoning Resolution, which would allow skyscrapers to have a slab-like shape and additional floor area in exchange for the inclusion of ground-level open spaces. When he was designing the CBS Building, Saarinen had calculated that each story would need to have a floor area of about to be profitable, even though the new zoning would have allowed only for each floor.; . The presence of the plaza around the CBS Building helped influence the content of the zoning resolution, which was passed later in 1961.; . In the 1980s, an additional plaza was built to the east, connecting 52nd and 53rd streets and separating the CBS Building from EF Hutton's then-new building at 31 West 52nd Street. Large planters were added around the plaza in the 1990s and demolished in the 2020s.
Facade The facade consists of vertical concrete piers clad with Canadian black granite, alternating with 5-foot-wide vertical bays of dark-tinted glass.; ; ; ; The design was intended to "keep glass areas to a desirable minimum", according to the contractors, while also permitting natural light from multiple angles. John Dinkeloo, one of Saarinen's associates, also believed that dark stone was better than glass at showing strength.; At the time of the building's construction, granite was generally associated with strength, while concrete was largely considered comparatively weak. The combination of black-granite piers and dark glass make the CBS Building appear as a granite slab from some angles.; ; . The facade led to its nickname "Black Rock",; ; . though CBS cites the building's proximity to Rockefeller Center as another influence for the nickname. The piers are triangular,; which Architectural Record said made the piers appear as a "continuous accordion pleated granite faced wall" when perceived from a certain angle. Architectural writer Ada Louise Huxtable characterized this effect as "trompe-l'oeil",; and Dinkeloo called it an example of "op architecture".
The sides of the piers extend outward 45 degrees from the building line, thereby creating a 90-degree angle at the tip of a "V".; ; . Each of the CBS Building's corners consists of two V-shaped piers, which appear as a massive load-bearing chamfer, though this effect is purely aesthetic.; The northwest-corner pier bears no load; a section of that pier was designed to be removable so large mechanical equipment could be lifted into and out of the building. Unlike other contemporary skyscrapers with load-bearing walls, in which walls on the lower stories are thicker than those on the upper stories, the piers in the CBS Building are of a uniform width.; ; . During the construction process, CBS executives and Saarinen's team considered using synthetic granite for the facade, but CBS chairman William S. Paley ultimately decided to use genuine granite, since it was more durable.;
The piers divide the west and east facades vertically into 12 bays, while the north and south facades are divided into 15 bays.; ; . The glass panes contain bronze-finished aluminum frames that are about tall on the ground story and tall on upper stories.; . The panes are separated vertically by windowsills between each story. The windows are recessed from the piers on the exterior and on the interior. For insulation, of polyurethane foam was sprayed in the piers. According to the insulation contractor, the CBS Building was the first New York City high-rise to use polyurethane as insulation.
To make the building appear imposing, Saarinen did not include a main entrance from Sixth Avenue in his design, because he did not want to modify the piers on that side. He also refused to use entasis—applying a convex curve for aesthetic purposes. The main entrances were instead placed on the 52nd Street and 53rd Street sides, though small doors were later installed on Sixth Avenue.; ; . On 52nd Street, the entrances are in the seven center bays and consist of single, double, and revolving doors; the easternmost set of doors leads to the ground-level restaurant. There are also seven entrances on 53rd Street, but the entrance to the restaurant on that side is separated from the other entrance doorways by a window. On the east facade are doorways that lead directly into the restaurant space. On the second story, a mechanical floor,; . there are metal grilles instead of glass panes. Similar grates are placed at the top story, also a mechanical floor.
Structural features
The CBS Building has a superstructure made of reinforced concrete;; ; it was the city's first skyscraper with a concrete superstructure to be built after World War II. Paul Weidlinger of Saarinen's engineering team said: "Too many people were saying 'it cannot be done' and we were itching to show them."; . Saarinen's team had considered making a superstructure of steel, as well as a superstructure with a mixture of steel and concrete, before deciding on an all-concrete structure after evaluating the cost of each option. During the planning process, the price of steel surpassed the price of concrete, influencing the team's decision. The concrete used in the CBS Building's floor slabs was 25 percent lighter than that used in conventional concrete slabs.