The proposed redevelopment of 640 Fifth Avenue (Crowell-Collier Building) located on the northwest corner of Fifth Avenue and Fifty-first Street called for the addition of 35,000 sf of unrealized zoning area, the redistribution of the total gfa into a series of more efficient and consistent floor plates and a program to upgrade the 1950s era building to meet or exceed the standards of modern Class A boutique office space. The owner’s desire to find a design solution for the tower and lobby upgrade that could be implemented while the existing building floors three through eight remained occupied was further complicated by the recent renovation of the building’s ground, mezzanine and second floor for a significant new retail tenant. Any new structural loads imposed by the proposed new massing would need to be resolved within the existing structural grid without the need to reinforce existing structure below the ninth floor in tenanted space or impact the existing foundations.
The existing 18-story Indiana limestone building designed by Leonard Shultze & Associates in 1948, to house the Crowell-Collier publishing offices, attempted to relate to the character and scale of the adjacent Rockefeller Center complex. The building’s response to the zoning envelope in the form of a series of convoluted setbacks rendered the building a complex cubic form, in contrast to the more elegant vertical layering of the Rockefeller Center massing. Lewis Mumford suggested that the design was “an example of eclecticism without conviction,” an attempt to reconcile the traditional and the modern that managed “to combine the saddest features of each.” The floor-by-floor varied setback section also resulted in a random mix of oddly-shaped floor plates punctuated by a forest of closely spaced low-capacity columns. The sectional misalignment of the structure relied on a system of deep transfer beams, limiting ceiling height within the office space to 8’-0”. The building’s architecture was interpreted as a missed opportunity in a context that offered significant challenges and even greater rewards. The building’s prominent Fifth Avenue address across the street from St. Patrick’s Cathedral at the northern limit of the Rockefeller Center complex placed it within the center of midtown Manhattan’s most significant public urban space.
The decision to completely bifurcate the material expression of old and new, rendered the existing nine-story limestone base closer to the series of four existing international building podiums of Rockefeller Center that extend out to Fifth Avenue. Within a massing that collages the grain and proportions of the RCA Building, the limestone base is then host to a new jewel-like 12-story glass tower above, that sits in an elevated garden plane, punctuated by the four rooftop gardens of Rockefeller Center. The city is interpreted as a stratified set of distinct horizontal planes with a landscaped platform floating eight floors above the street datum and the lower plaza (skating rink) sitting two levels below a thin ground plane at street level. The relationship of host and visitor is reinforced through the distinct material transformation within this section from heavy limestone cladding with punched openings to a delicate glass and stainless steel curtain wall above. The new glass tower façades, along with St. Patrick’s Cathedral and the Rockefeller buildings, define the new limits of an urban room within which the floating garden plane is suspended. This room reinforces the idea of the city as theater as the movement of Fifth Avenue intersects with the east west grain of the pedestrian open space defined by the Channel Gardens and the lower plaza.
An elegant solution for the tower massing was determined within the original zoning envelope and the existing structural armature. The new tower is comprised of three rectangular transparent green glass volumes defined by a series of vertical layers oriented in the east west grain of the Rockefeller buildings. These layers are defined at the curtain wall surface along the Fifth Avenue facades by vertical mullions with delicate stainless steel outriggers that extend out from the wall. A more subtle horizontal pattern is articulated behind the glass by a corrugated aluminum panel within the shadow box, and the single line of the interior tubular guard rail that floats 2’-10” above the floor level. The east west orientation of the floor plates and the shearing of the two primary volumes maximize the buildings south, and east-facing exposure to the Beaux Arts rooftop gardens below and the Gothic articulated roof and façades of St. Patrick’s Cathedral. The additional two story lower volume receives the extension of the roof gardens in the form of terrace planting layered behind transparent glass parapet walls.
A perimeter deluge sprinkler system was employed at the curtain wall interior to reduce the NYC spandrel dimension requirement to permit a 2’-6” shadow box and an uninterrupted vision glass panel that extends 9’-6” from floor to ceiling to take full advantage of the panoramic Fifth Avenue views. Special effort was taken to maximize ceiling heights within the modest 12’-0” floor to floor structure of the existing building. Detailed plumbing and air distribution drawings produced by the architect permitted the close coordination of mechanical and structural work to achieve ceiling heights of 9’-6” minimum at the perimeter office zone. An elaborate network of beam penetrations and subsequent reinforcing was required to accommodate the new mechanical system distribution within minimum construction tolerances.
The penthouse floor height was increased to accommodate 14’-6” vision glass panels that extend up another 40’ to enclose a lantern that conceals the mechanical and window-washing equipment behind a floodlit corrugated screen wall.