150 North Riverside is Most Eye-Grabbing Chicago Skyscraper Since Aqua Tower

As seen in Chicago Tribune

You know a new building has struck a nerve when people give it nicknames like “The Tuning Fork” or “The Guillotine.” Or when the building appears alongside the likes of Willis Tower and Marina City on tour-boat posters that tout a chance to see Chicago’s architectural icons.

150 North Riverside, the slope-bottomed riverfront office tower that officially opened Thursday, is the boldest, most eye-grabbing Chicago skyscraper since Jeanne Gang’s curvaceous Aqua Tower debuted in 2009. Its base, which flaunts sloping diagonal columns and glass walls that look blade-sharp, raises the question: Why did they do it that way? People also have been heard to wonder whether a strong puff of wind might blow the high-rise over.

The most important question, though, centers on whether this 54-story high-rise is a genuine synthesis of structure, function and form, not just eye candy.

I’d say it meets that bar, though I wouldn’t call it a masterpiece on the level of the Bertrand Goldberg-designed Marina City and am underwhelmed by aspects of the design. The tower nonetheless yields real benefits: development of a prime riverfront parcel once considered unbuildable, more than an acre of landscaped open space and a powerfully sculpted office tower that writes the latest chapter in the fabled Chicago story of integrating engineering and architecture.

Like doctors and lawyers, architects are said to “practice,” with each commission yielding lessons that inform the next one. And so it is here. The tower’s architects, Chicago’s Goettsch Partners, and their structural engineers, Seattle-based Magnusson Klemencic Associates, have played this game before.

Forty years ago, Magnusson Klemencic collaborated with World Trade Center architect Minoru Yamasaki on Seattle’s Rainier Tower, which stacks office floors atop a flaring pedestal. As in Chicago, the unusual look has sparked nicknames: “The Golf Tee Building,” “The Wine Glass” or “The Beaver Building,” a reference to Rainier Tower’s base resembling the bottom of a tree gnawed on by a beaver.

More recently, Goettsch Partners completed an Abu Dhabi office and financial complex that contains four office buildings that, while shorter than 150 North Riverside, look much the same overall. Thus, when 150’s design was unveiled in 2013, some accused the firm of ripping off its own work. Yet the slope-bottomed Abu Dhabi buildings arose from choice. 150’s unusual form was birthed by necessity.

For decades, the 2 acre site — which is bounded by the Chicago River’s south branch, the viaducts of Lake and Randolph Streets, and the beefy brick condo building at 165 N. Canal St. — was a dusty pit into which pedestrians gazed. Trains rumbled through the parcel’s western third, which was owned by Amtrak. More trains ran through the middle slice, owned by the city of Chicago. Anyone who wanted to build on the eastern third had to leave at least 30 feet for a city-mandated riverwalk.

All that left veteran Chicago developer John O’Donnell — a former John Buck Co. president who left to found Riverside Investment & Development — with little room to maneuver.

The solution that overcame these constraints is ingenious: 150 North Riverside is pushed to the eastern portion of the site. An extra-thick concrete elevator core braces the building against the potentially toppling force of the wind. On the upper floors, a steel frame attached to the core carries the weight of the building and its contents (the “gravity load”) downward. But the frame’s columns never reach the ground, as they do in a typical structure.

Instead, beneath the eighth floor, massive steel columns slope inward to the core. The core, in turn, brings the gravity load down to 110-foot-deep caissons that reach to bedrock. The railroad tracks are thus left undisturbed and there’s room for a riverwalk. Yet this solution, which the architects call a core-supported structure, does not fix everything.

Because O’Donnell needed to build tall (and thus profitably), 150’s north and south flanks look as thin as a reed. Their aspect ratio — the building’s height relative to the width of its core — is a jaw-dropping 20-1. Imagine a reed blowing in the wind. Now imagine that that reed is an office building with people inside who get as queasy as passengers on a storm-tossed ship.

To prevent that, the engineers inserted two enclosed concrete vaults near the building’s top. The water in the vaults, which are called “tuned liquid dampers,” is not for swimming. When the wind pushes the high-rise one way, the water sloshes the other way, damping wind-induced sway and eliminating the threat of rattling chandeliers and whitecaps in the toilets.

The beneficial outcome of these structural acrobatics is immediately evident when you approach 150 North Riverside. It is a true “tower in the park.” More than three-quarters of its site is open space, much of it attractively landscaped with swirling curves that play against the building’s insistent right angles. Chicago’s Wolff Landscape Architecture handled that part of the project.

The open space appears user-friendly, with a tiered amphitheater along the river and a raised park that’s built atop a 72-space parking garage on the site’s western side. Office workers going to and from nearby train stations already are streaming through the building’s street-level plaza and riverwalk. Curving glass walls that extend outward from the building are supposed to prevent downdrafts from knocking over pedestrians.

Thus, 150 North Riverside effectively joins with the landscaped plaza of the recently completed River Point office building, a 52-story high-rise at 444 W. Lake St., to enhance the “confluence district” of the downtown riverwalk (so called because it lines the meeting of the Chicago River’s north and south branches). In some ways, 150’s plaza improves upon its River Point counterpart, which had to be raised several feet above street level to leave room for trains below. Here, in contrast, much of the plaza is right at ground level, enabling the flow of pedestrians.

The abundant open space also works to the advantage of the building, serving as a forecourt for 150’s boldly sculptural, yet structurally grounded, form. The design, by Goettsch Partners’ Jim Goettsch and the firm’s Joachim Schuessler, takes advantage of the open riverfront site with a series of projections and setbacks that distinguish the building from an ordinary box and create multiple corner offices on each floor.

Undulating vertical fins lend much-needed texture to the broad east and west facades; the fins also suggest the ever-shifting character of the river’s waters.

The building’s strong verticality, emphasized by metal panels that express its structural columns and granite cladding that suggest its core, sets up a winning conversation with the dominant horizontality of nearby River Point. The two make a fine early 21st century pair.

Still, there are faults. The underside of 150’s sloping eastern facade, where louvers for mechanical systems are plainly visible, looms awkwardly above the riverwalk. The high-rise’s north and south flanks appear flat when seen head-on. Most important, the building’s structural innovations are largely limited to its base. Above the eighth floor, it is essentially a conventional office building. At Goldberg’s Marina City, in contrast, the big structural idea — a circular core surrounded by modules that resemble the petals of a flower — informs the entire design, from pie-shaped apartments to balconies.

I’ll give 150 North Riverside this much in comparison to Marina City: It’s got a riverwalk — Marina City has none — and it meets the ground more effectively, especially in the high-ceilinged, glass-sheathed lobby that adorns its western side. This enclosure, which includes structural columns made of glass, is bracingly transparent, albeit somewhat cool and over-scaled. Yet it’s enlivened by handsomely detailed marble walls, a digital light sculpture of thin vertical strips and a second-floor overlook that eventually will contain a Starbucks coffee shop. The Lake Street “L” train shoots by seating for the coffee shop, like a kinetic sculpture.

Perhaps 150 North Riverside is a little unnerving, challenging our desire for buildings that not only are stable but look stable. But I suspect you’ll get used to it and may even come to appreciate its gravity-defying design. This is a gutsy building, one that rises to the challenge of its site. One hopes that Goettsch and O’Donnell can equal or exceed it in a planned 51-story office tower that would be located across the river at 110 N. Wacker Drive. What they’ve achieved at 150 is not perfect, but it’s very good indeed — a persuasive blend of the pragmatic and dramatic.