16 sep 19 | New York Magazine

The Challenges of Constructing New York’s Tallest Apartment Building

By Justin Davidson

When Central Park Tower at 217 West 57th Street officially tops out at 1,550 feet on September 17, it will (if you don’t count the 400-foot spire atop One World Trade Center) become New York’s tallest building. It has already transformed the skyline, paired with the 1,428-foot residential needle on the next block at 111 West 57th. I recently toured the construction site with the building’s two Chicago architects, Adrian Smith and Gordon Gill. Smith designed the world’s tallest building, Burj Khalifa in Dubai, as well as the future tallest, the kilometer-high (3,280-foot) Jeddah Tower in Saudi Arabia. Moving from sidewalk to a gajillionaire’s aerie — a 15,898-square-foot three-floor penthouse — we talked about how a 131-story tower can possibly fit into our city.

Gordon Gill: How well do you know the building?

Justin Davidson: I can see it from all over the city, including from my living room. At first, I thought it was just the construction hoist that was blocking my view of the Empire State Building, but I guess not.

G.G.: One of the perils of living in an urban context.

J.D.: From the street, this looks like several buildings in one: a seven-floor Nordstrom at the base, a wing to the west, a cantilevered section to the east, and the tower. How do they all hang together?

G.G.: The site goes from 57th through to 58th Street and all the way to Broadway. When you’re designing a super-tall building, most of the time you’ll plant the concrete core in the dead center of the site. If we had done that, we’d have wound up with piecemeal retail. So the first move was to slip the core to the side. When you do that, the tower follows.

J.D.: So that’s how you get the section that sticks out above the Art Students League?

G.G.: Right. A lot of people questioned whether we had respect for that building [an 1892 landmark]. But a lot of detail and study went into that. They have a beautiful skylight in north-facing studios for the natural light, and we didn’t want to compromise that.

J.D.: They were worried about glare.

Adrian Smith: Yes, but the exterior wall above the Art Students League roof is solid, with no glass, just a soft zinc surface, so you get a very subdued reflection.

J.D.: How do you design such a huge building to slot into such a dense area?

G.G.: Everyone wants a view of Central Park, but we had a big building right in front of us [220 Central Park South]. It’s like being at the theater; if everyone’s in rows trying to see the stage, nobody can see anything at all. The solution is to stagger the seats. When we moved the tower off-center to get better retail spaces, we discovered an opportunity to capture incredible direct and oblique views. That’s why the building is stepped and staggered in every direction — north, south, east, and west — walking all the way up to 1,550 feet. If you look at this building from a distance, it has a strong ethos and a sense of stability. On the other hand, there’s a lot of movement. The trick was managing all that activity without getting overly effusive.

J.D.: It’s true — this isn’t one of those seamless glass prisms. Do all those notches and fins have any other purpose?

A.S.: It’s all about wind. The wind behavior in Manhattan is unique.

J.D.: Because it’s bouncing around all these other buildings?

A.S.: And because you get hurricane-force winds.

J.D.: So how do you figure that out?

G.G.: We come up with the basic form, then drop it into a scale model of midtown and perform wind-tunnel analysis on it. We tweak the shape, we cut it, we shift it, we slide it. We have a pretty good intuition about what’s going to happen, but we’re always learning more about keeping everybody comfortable and happy inside.

J.D.: Can you get a little more specific?

G.G.: As the wind goes around the building, it accelerates, and it creates vortices that alternate, causing the building to move from side to side. Sometimes we can use that phenomenon, cutting openings for the wind and converting it to energy with turbines. Here, we’re not trying to bring the wind through the building; we’re managing it, shaping the notches to optimize wind flow. A building is like an instrument: You use science to make a kind of art.

J.D.: So is a super-tall skyscraper fundamentally different from a plain old high-rise, or is it just a bigger version of the same thing?

G.G.: People say things like “Oh, a 120-story building is just two 60-story buildings stacked.” That’s not true. The wind speeds are different, the performance is different — everything changes. If you make a mistake on one of these buildings, you have to multiply it by a thousand.

J.D.: If you get it wrong, can you adjust?

A.S.: When Taipei 101, which was the world’s tallest at the time, was under construction, they had reached three stories or so when they finally got the wind-tunnel test done. And the test said this building is going to move like crazy — you have to change it. They had to cut a sawtooth on every corner, put in a 660-ton damper, and roughen up the walls here and there. Otherwise, it would have failed. I mean, it wouldn’t have collapsed, but it would have been very uncomfortable.

J.D.: Aside from the way it accommodates our overcomplicated wind patterns, what else makes this a distinctively New York building?

G.G.: The standards in New York are very high and so are the expectations. That leads to delicate detail and a lot of attention paid to where the columns are, the size of the glass, the proportions of the rooms, the acoustic isolation. It’s not a loose design.

A.S.: Look at the stainless-steel fins on the exterior. Eventually, when the protective coating comes off, you’ll see gradations of light on them, the way they sparkle and are offset from the wall so the façade has a sense of depth and richness.

J.D.: They look like shiny pinstripes.

A.S.: When we do the tallest building in China or Dubai or Saudi Arabia, they’re exuberant about that. New York is a much more sensitive environment, so we have to try to do the right thing for the site, design as beautiful a building as we can, be very respectful of the neighborhood, and try to improve on what’s there.

J.D.: Right. Some of your towers effectively create a new skyline from scratch. Here, you’re making a statement in a historic skyline. That’s a heavy responsibility.

G.G.: A building has to speak to you from the street, from the middle, and from the skyline. So that conversation on the skyline is between us, the Chrysler Building, the Empire State Building, and all the other iconic symbols of the city. We hope that this building will participate in that dialogue, not just because of its height but because of its character.

A.S.: The lighting is part of that: It’s subtle, not garish. The tall vertical slots at the top will be lit up nicely with white light, and it’s a big enough mass to be seen among the cacophony of windows.

J.D.: How about during the day?

A.S.: Because of the kind of glass we’re using, it won’t be this big blob but will blend with the sky and reflect it. The building will have this disappearing quality.

J.D.: It’ll just vanish, huh? [Skeptical raising of eyebrows.] We’ve seen a spate of these very thin residential buildings, especially along 57th Street. The global hyperluxury real-estate market made them financially feasible, but what recent technological advances make them possible?

G.G.: The materials, for one thing. On Burj Khalifa, they ran concrete through tubes in the desert, and it looks like water but it hardens to an incredible strength. More important, though, is the kind of deep analysis of performance characteristics, the relationship between structure and architecture. We don’t want to create a form, then shove a structure into it and try to make it work. We fuse them from the beginning.

A.S.: Every time you do the tallest building in the world, it’s completely new. You study and test, and you find new issues. When I was doing Jin Mao [in Shanghai in 1999], I remember saying, “We’re going to add 10 percent to the body of knowledge about super-tall buildings.” Well, there are 100 buildings this tall now, either in the planning stages or built. Each time you do that, you learn something more.

J.D.: So if the zoning and the neighbors allowed it, could you have gone even taller right here?

A.S.: Oh yeah. Jeddah Tower is twice the height of this one. You could drop that in here, for sure.