“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 recalled: “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 said, “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) recalled 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.

Consequently, Horch said, “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 added, 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 said, “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 recalled 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 recalled. “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.

“Once the leasing guys saw this,” Cleary said, “you could hear the breath getting sucked out of the room.”

The building is a model of 21st-century integrated management as well as advanced thinking in design, sustainability, and habitability. Now that it is open, its managers won’t be the only ones whose breath is taken away.