What Holds Eleven Times Square’s Leaning Glass Steady
An awkward Manhattan lot produced an outward-sloping tower, open corner offices, and a structural system anchored deep into bedrock.
At Eleven Times Square, the glass seems to reach beyond the building beneath it. Above a recessed base, the north face slopes outward as it rises, giving the tower a silhouette that looks unusually top-heavy. The apparent imbalance is part of its appeal. It also points toward an engineering story that extends from the office windows into Manhattan’s bedrock.
The building’s stability depends on a carefully arranged partnership: a concrete core, comparatively light steel framing, and anchors that resist uplift at the foundation. Its unusual shape gave the engineers a problem to solve, while their solution gave the architects more freedom at the edges.
Developed by SJP Properties and designed by FXFOWLE, now FXCollaborative, the tower occupies the Eighth Avenue frontage between West 41st and West 42nd Streets. Across the avenue is the Port Authority Bus Terminal; immediately south is the New York Times Building. This is a meeting point of commuter infrastructure, corporate offices, and Times Square’s entertainment district. SJP Properties
Where it is
Eleven Times Square, Eighth Avenue between West 41st and West 42nd Streets, Manhattan, New York.
The first complication was the parcel itself. Its L-shaped geometry made a conventional central-core arrangement unsuitable. In many office towers, a stiff core sits near the middle, with usable floors surrounding it. Here, architects and structural engineer Thornton Tomasetti placed the core in the crook of the L, finding an arrangement that efficiently resisted both sideways movement and twisting. The Skyscraper Center
Those are different structural concerns. Sideways movement is the familiar image of a tower bending under wind. Twisting, or torsion, involves rotation in plan. Imagine looking down at a floor while its corners turn around a vertical axis. Where wind forces act relative to the building’s resistance matters as much as the outline of the floor.
The core’s position therefore had to work with the whole building. An apparently tidy location within one portion of an irregular footprint would not necessarily produce an efficient structure overall. At Eleven Times Square, the side core answered the geometry of both wings, even though it remained offset from much of the tower’s mass.
The north side introduced another complication: a 30-foot cantilever. Steel floor framing helped limit the weight associated with that projection, reducing the resulting torsion and lateral drift. The choice connected the architectural gesture to the structural response. How far the building reached outward and how heavily it was built could not be treated as separate decisions. The Skyscraper Center
Keeping weight down, however, brought a foundation tradeoff. Wind acting on a tall structure produces an overturning effect. That can increase downward pressure on one side of its support while creating an upward demand on the other. At this relatively narrow, lightweight tower, the engineering design had to address tension beneath the concrete core.
The answer was 77 rock anchors drilled 40 to 60 feet into rock. Each three-inch-diameter bar was tensioned to 600 kips, equivalent to 600,000 pounds of force. The bars were locked off at the footing and extended upward into the concrete core walls, providing a connection between the tower’s principal stiffening element and the rock below. These installation details were documented in the Spring 2009 issue of Metals in Construction. Steel Institute of New York
Uplift describes a force the foundation must resist. It does not mean the skyscraper routinely leaves the ground. The anchors supply hold-down resistance where the structure’s own weight is insufficient to balance the design demand. That distinction makes the engineering more revealing: the apparent lightness at the skyline depends partly on an exceptionally substantial connection underground.
Inside, the structural arrangement produces a more immediate reward. Columns were placed at least 15 feet from corner windows. Architect Dan Kaplan described the resulting experience as feeling suspended in a bay window above the city. A separate 45-foot cantilever at the southwest corner clears the corporate lobby entrance, with a truss above carrying the interrupted column line. Steel Institute of New York
An open corner still has a load path. Its floor carries weight back through framing to structural supports. What disappears is the column directly beside the glass, allowing the view to continue around the room. For an office tenant, a technical decision about the relationship between concrete and steel becomes an everyday spatial experience.
The outward slope also serves a commercial purpose. FXCollaborative explains that it adds leasable space at desirable upper elevations. Below, a six-story base establishes the building’s presence at street level and accommodates retail and large displays. The shape responds simultaneously to the parcel, the office market, and the theatrical scale of 42nd Street. FXCollaborative
Even the glass changes with orientation. The architect specifies reflective glazing and perforated aluminum sunshades on the southern and western faces, where sunlight is stronger. These elements manage daylight and glare while giving the exterior texture. The tower’s different faces reflect different environmental conditions as well as different views of the neighborhood. FXCollaborative
Construction made the division between core and frame particularly visible. Plaza Construction built the concrete core ahead of the surrounding steel, deploying one crane for the core and two for steel erection. Its project record lists completion in 2011 and describes a 601-foot tower with 40 occupied stories above grade. During construction, the concrete spine advanced into the skyline before its surrounding floors caught up. Plaza Construction
Seen from the sidewalk, Eleven Times Square compresses all of this into a few striking lines. The sloping glass draws attention first. Behind it, the core organizes resistance, steel carries projecting floors, and buried anchors complete the connection to the ground. The unusual parcel helped generate the architecture, but making that architecture useful required decisions at every scale, from the corner office to the bottom of the footing.
Sources
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