The 1,401-foot, 67-story, 1.7 million-square-foot One Vanderbilt topped out in September. Despite its scale, complexity, challenging site, and high-performance features, it is moving ahead of schedule and under budget. Partners on the project attribute this achievement to tight coordination, a steel-first sequence, and an all-star design and construction team.
Written by Bill Millard
Nick Davis leads a crew working on high floors at One Vanderbilt. With deep family roots in Ironworkers Local 580, he has the craft of construction in his DNA; working for Permasteelisa’s installation component, Tower, he made foreman in just five years. After observing a welder perched on a perilously cantilevered hydraulic lift 57 stories above 42nd Street, he supervises two journeymen and an apprentice in guiding curtain-wall units into place. These 1,750-pound unitized panels of steel, glass, and terracotta are brought up by elevator to the next floor below, then hoisted up one last level by crane, with a 180-degree rotary flip on a count of three right before placement, so the cable-attachment points put tension on metal rather than the ornamental terracotta spandrels. “We can’t send them out how we usually would, face down,” Davis notes; “So that’s face-up, so now we have to send them out and actually rotate them in air… It’s an extra step on every panel.”
Moving patiently between tasks, getting the details right efficiently, and taking the time to explain them to visitors, Davis typifies the personnel working on this project: on top of his game, at ease with the complexities of the job. His and his colleagues’ expertise is part of the reason One Vanderbilt is ahead of its projected schedule and under budget. (Demolition at the site began in 2015, the groundbreaking occurred in October 2016, and the topping-out date was originally set for January 10, 2020; the team reached that milestone on September 19, 2019, and estimates for the temporary certificate of occupancy now run from August to October 2020.) As the key factor making this pace possible, says Edward DePaola, president and CEO of Severud Associates, “I think it’s a combination of the right design and construction team,” and “they’ve got to put the best people on it…. It’s real dedication and the ability to think and perform way beyond what’s normal.”
Coordinated design and construction planning, DePaola points out, sped this project from the outset. As he and others noted at a panel discussion about One Vanderbilt for the American Institute of Steel Construction (AISC) on September 26, this was neither a design-bid-build nor a design-bid project, but what he calls “just an enhanced design with detailing.” “The job wasn’t fast-tracked; it was faster-tracked,” said KPF’s architect Andrew Cleary, with parametric models coordinating all subcontractors at early design stages and preventing onsite clashes. “If we catch one hitch that typically would happen during construction, we’ve paid for these guys to come in early,” Cleary noted; “if we catch two, we’re ahead of the game.”
General contractor Tishman hired independent detailers for each trade before subcontractors were on board, DePaola recalls: “We had a structural steel Tekla modeler working for Tishman, actually building the Tekla model as we were designing…. We supplied only up to Revit; we gave them Revit information; they did Tekla, which is much more accurate than Revit as it relates to exact beam lengths [and] ability to put all the bolts and welds right into the model.” When Banker Steel and other contractors came on board, the Tekla model saved them all months of work. “Steel was going to be fabricated,” DePaola says, “so that [the other subs] had to be thinking of things a year in advance of when they normally would, and everybody pulled their weight.”
This advantage required unprecedented early-phase coordination, beyond what many teams could handle. Mechanical engineer Christopher Horch of Jaros Baum & Bolles (JBB) recalls the extensive revisions addressing intertwined architectural and business concerns. As a spec developer building, One Vanderbilt needed extreme flexibility from the MEP standpoint, depending on which tenants would sign on, now or in the future; as a major tower located next to Grand Central Station, it needed to preserve sightlines and street-level plaza space. The electrical transformers are located alongside the large chiller plant and other major MEP systems on the 12th floor rather than at sidewalk level, and KPF designated a five-foot plenum on the perimeter of mechanical floors (the fourth, fifth, and 12th), along with vertical intake/exhaust slots by Permasteelisa rather than conventional large gray louvers, so that these floors would visually read no differently than office floors by day or night. With all of those moves, square footage for MEP was squeezed.
Consequently, Horch says, “during our schematic design phase, they were changing the building almost on an hourly basis,” at one point increasing floor-to-floor height by two feet at the 12th floor. “It was a big change, but it was able to be absorbed, because we were only in DD [design documents], and those things get flushed out over time. If we had not done that level of detailing, we would not have caught it until construction, and it would have had a major impact on the schedule and cost.” The efficient procedure also gave bidding contractors such confidence, he adds, that “the bids came back… within a few percentage points of each other on all trades from an MEP perspective, which is also unheard of.”
“When Tishman put this out for bid, they gave them the Tekla model for the whole building,” DePaola says, “with a handful of typical connections throughout the building, but with the bottom six levels detailed, and they said to the bidders, ‘This is it, guys. If you can’t do these details, if you’re going to come back and say you want to change X, Y, and Z, you’ve got to tell us how much longer that’s going to mean to your schedule, compared to if you took it exactly the way we gave it to you. And speak now or forever hold your peace.’“ The contractors made the commitment, enduring weekly meetings for a year and a half, locking in details down to the level of coordinating structural steel and ductwork in elevator lobbies. “We were asking them to commit to that geometry when they were in DD, and most architects wouldn’t even be thinking about the lobby elevators until near the end of construction documents.”
One Vanderbilt is a hybrid building with a concrete core and a steel frame around its perimeter. It thus needed to solve the recurrent problem of steel and concrete components rising at different speeds. DePaola recalls other projects that had to give concrete contractors a head start on steel contractors, leading to scheduling challenges as well as structural ironworkers safety objections to working below another trade. Here, Severud drew on its experience with Philip Johnson and John Burgee’s IDS Center in Minneapolis (1972), a pioneering project in steel-first construction, to erect steel ahead of rebar, interior and exterior formwork, and concrete shear walls. “We worked out a different type of form system, so that the inside is a climber and the outside is hand-set,” DePaola recalls. “On this job Navillus did the concrete, and they were right there; we never slowed down. Everything worked like clockwork.” The project’s foundation work included a 4,200-cubic-yard single continuous pour in February 2017, a 27-hour operation that marked the largest such pour in the city’s history—“like somebody coordinated a ballet,” DePaola told the AISC audience.
One Vanderbilt will be New York’s fourth highest building (after One World Trade and two ultrathin residential buildings under construction on 57th Street). Its adjacency and underground connection to Grand Central make it the ultimate in transit-oriented development —particularly when the Long Island Rail Road enters the station under the East Side Access plan a few years from now—as well as a high-visibility emblem of the newly rezoned Midtown East commercial corridor. Though any commercial building on this scale attracts scrutiny over pedestrian traffic, shadows, and aesthetics, One Vanderbilt’s design respects its Beaux Arts neighbor and its street-level neighborhood, forgoing maximum square footage in favor of a tapered form admitting light onto the street and the new car-free Vanderbilt Plaza, attaining a floor-area ratio of 30 (and realizing higher target rents on high floors to offset area sacrifices, based on view analyses from real-time parametric analyses and drone photographs; “once the leasing guys saw this,” Cleary said, “you could hear the breath getting sucked out of the room”). The building looks to be a model of 21st-century integrated management as well as advanced thinking in design, sustainability, and habitability. When it opens next year, its managers won’t be the only ones whose breath is taken away.