150 North Riverside claims its place in Chicago’s skyline

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The finely tuned office tower carries Chicago’s architectural legacy into the 21st century

Just a week after it officially opened, 150 North Riverside is abuzz with activity. Office workers can be spotted eating lunch outside in the building’s ground-level park while tourists stop to look up and snap photos of the tower’s unique core-supported shape. Crews are still putting the final landscaping pieces together while others are working to build out the office spaces for the building’s high-profile commercial tenants. However, the sleek contemporary tower has formally claimed its place in the Chicago skyline.

The final product is a 54-story skyscraper and nearly 1.5 acres of public park space on coveted riverfront property. But visitors passing through the site or walking along the riverwalk might not have ever known that for years, the property was an underutilized stretch of train tracks and barren riverbank.

“The defining feature of the building is the base and the superstructure design,” Tony Scacco of Riverside Investment, the project’s developer, explains. “But the reality of the matter is that the building helped solve a site constraint that precluded development on one of the most prominent sites in Chicago for close to 80 years.”

And to repair the urban fabric and make the 1.2 million-square-foot tower possible, Riverside Investment formed a team of architects, structural engineers, and construction workers that had an extensive knowledge set and collective experience in building on challenging sites.

Rob Chmielowski of Magnusson Klemencic Associates, the Seattle-based firm tapped by Riverside Investment to oversee the building’s structural engineering, tells us while the building’s concrete core appears to be narrow, the tower “has a very strong spine.”

“We drilled 110 feet down into the ground and actually socketed the caissons five feet into the bedrock,” Chmielowski says. “So, we’re literally anchoring the building deep down into the earth.”

So, why did the design team ultimately decide to go with a shape and appearance that looks almost like something from a science-fiction film? There simply just wasn’t a lot of room to work in, Scacco says.

“We knew that we only had 6,000 square feet in which we could land building superstructure,” Scacco explains. “In order to achieve the relevant floor plate efficiencies and design requirements that in our mind are absolutely necessary for a modern trophy office tower, we had to have a 28,000-square-foot floor plate.”

Essentially, the architects and structural engineers were tasked with designing a conventional 46-story office building that would stand on an eight-story base. The tricky planning and construction of the tower was further complicated by the constraints of being flanked by the Chicago River on the east and seven active Amtrak rail lines to the west. When standing in the center of the lobby, visitors are standing just 20 feet above operating Amtrak trains, Chmielowski explained.

To give the building’s base a solid, substantial look and feel, architect Joachim Schuessler of Chicago’s Goettsch Partners says that the firm decided to clad the structure’s concrete core with a dark granite. But there are many other design tricks employed throughout the tower. Because of building constraints, the team hung a glass curtain from structural fins to form the tower’s ground-level lobby. The glassy wall shields visitors from Chicago’s extreme weather, but it also obscures the feeling of being either fully inside or out.

And while the building, with its many details, changed numerous times since it was first conceived of five years ago, the basic shape of the tower has remained unchanged since the very beginning. “Everything has changed many, many times except for the basic diagram of the building, because nothing else would have really worked,” Schuessler suggests.

The tower has not only solicited awe and wonder from passersby and tourists on riverboat cruises, but it’s even earned itself a few nicknames. I’ve always felt that the building, with its narrow base, resembles a tuning fork, but other observers have seen objects like an upside-down wine bottle or a guillotine in the tower’s silhouette. Tony Scacco of Riverside Investment isn’t too amused by the nicknames, however. “We try to tune that stuff out,” he says.

Speaking of tuning things out, the tower features a complex tuned mass damper system that keeps the building from swaying and shifting under intense wind loads. A series of large tanks located in the center of the tower’s top levels contain 160,000 gallons of water that prevent the building from moving and from making its occupants feel sick.

There’s probably no other new building in Chicago that causes more people to tilt their heads and look up. With its narrow base, which expands out over the first eight levels, 150 North Riverside almost looks like a balancing act. And in some ways, it is.

“When the building tries to move one way, the damper water pushes the other way and settles the building,” Chmielowski explains. “It’s an equal and opposite force and the building always stay in tune. It’s basic. It’s literally water and big concrete tanks.”

Beyond the tower’s striking, almost gravity-defying appearance and the complicated engineering behind it, another important component of the project is its sprawling riverfront park space and new stretch of riverwalk. Scacco says that the tower’s 45-foot setback from the river allowed the development and design team to deliver a total of 1.5 acres of public space around the building. Scacco adds that Riverside worked closely with the City of Chicago and 42nd Ward Alderman Brendan Reilly “to get the public spaces just right.”

Chicago is a city known for its skyline and legacy of building tall, architecturally challenging towers, and 150 North Riverside, along with River Point, its next-door neighbor, are helping to push that legacy well into the 21st century. The tower, with its unique shape and complex structural systems, is a continuation of Chicago’s architectural narrative, which has seen the creation of numerous iconic skyscrapers that pair design with cutting-edge engineering.

The towers filling in the confluence of the Chicago River are proving to be some of the most exciting new buildings that downtown Chicago has seen in years. And as a collection, they all work well together. But what should we call them, or how do we define this emerging style? “It’s not minimalist, but it’s contemporary and solves all of the problems that need to be solved while being a significant contribution to the city,” Schuessler says. “I can’t name the architecture, necessarily—you’ll have to find your own name.”

The tower’s shape is a classic example of form follows function, Schuessler concedes. And while Jim Goettsch and Schuessler visualized the building’s final silhouette early on, there are no urban legends behind the tower’s design. “We don’t really have an iconic hand scribbles on a napkin,” Schuessler said. “I mean, sometimes it works that way, but most of the time it doesn’t.”