The first building on Northeastern Illinois University’s new El Centro campus will be curved to fit within the bend of the nearby Kennedy Expressway in Chicago. JGMA
Located on a bend in one of Chicago’s busiest thoroughfares, Northeastern Illinois University’s new satellite building will feature a curved geometry and striking sunscreen fins.
April 29, 2014—Its origin dating to the 1860s, Northeastern Illinois University (NEIU) became a public state university in 1949 and today serves more than 12,000 students in Chicago. Yet many people are unfamiliar with the university, which has its main campus on the city’s far north side. But that is sure to change once the university’s newest building—with its curved geometry and color-changing sunscreen fins—is completed next to one of the city’s busiest transportation corridors.
The building will be the first on the NEIU’s new El Centro satellite campus. The university created El Centro, one of its three branch campuses, in the 1960s primarily to serve the area’s growing Latino population. Now serving a diverse population, El Centro has been housed in leased space throughout the city but has outgrown its homes as its programs have expanded and enrollment has increased in recent years. The university expects El Centro to continue to flourish, so it committed to constructing a permanent purpose-built satellite campus for the branch.
University officials searched for a site that was large enough for the new building, close to public transportation and the communities El Centro serves, and in a prominent location on the city’s north end. They found what they were looking for in a site located on a bend in the Kennedy Expressway (Interstate 90)—a main artery that extends from Chicago O’Hare International Airport into the city’s downtown. Sharon Hahs, Ph.D., the president of NEIU, says the site has a “dramatic presence” along the expressway, which is traveled by approximately 400,000 vehicles a day. “The land was suitable for what we needed to do our programming, and the location was an extra plus,” she says.
University officials interviewed several architecture firms about designing the El Centro building. Chicago-based architecture firm JGMA (Juan Gabriel Moreno Architects) won the project by proposing a building design that would meet El Centro’s programming needs and capitalize on the project’s prime location to attract attention to the university. “Northeastern Illinois University has a wonderful legacy, yet doesn’t have the recognition it deserves,” says Juan Moreno, the president of JGMA. “We quickly arrived at the idea of the building as a billboard. It’s a billboard for the university, a billboard for the students, and a billboard for the community.” Chicago-based Forefront Structural Engineers, Inc., is serving as the structural engineer for the project and collaborated with JGMA to develop the design.
The building will be covered by color-changing sunscreen fins.
The fins will be gold on one side and royal blue on the
other—NEIU’s colors—so that the building appears one color to
inbound traffic and another to outbound traffic. JGMA
The 63,000 sq ft, three-story tall building will be curved in shape, enabling it to fit within the arc of the expressway for maximum visual impact. When viewed from the expressway, the building will be in the foreground and parking will be hidden behind it. “We were really intrigued with this idea that you have this fabulous downtown that has all of this recognition for architecture, yet we don’t have a lot of [noteworthy] architecture along the expressway,” Moreno says. “So part of the way we shaped the building ... was to have this visual link between our site and downtown, which I think is a terrific dialogue between the two, at least visually.”
Siting the building next to the expressway meant designers had to consider its acoustical properties. To muffle the hum of the traffic, the building’s ground floor near the expressway will feature steel columns with composite walls—a system that also creates the perfect interior space for a gallery in which the university can build upon its established legacy of artwork displays. In its upper levels, the building’s interior arrangement will prevent the noise from reaching the learning centers—classrooms, laboratories, lecture halls, and other academic spaces located at the middle of the building and along corridors positioned along the outer walls. “Instead of having a corridor at the center of the building and flanking classrooms on both sides, we put the corridors on the outside,” Moreno explains. “And those corridors become sound buffers to the classrooms.”
Much speculation exists about why the Kennedy Expressway has such a deep bend at this location, but the most logical answer is because the bedrock at the site is so close to the surface that it is visible in some nearby areas, Moreno says. That’s not ideal for road construction but is beneficial for constructing a foundation for a building, he notes. Bedrock at the construction site is just 10 to 15 ft below grade, so the building will be founded on spread footings with a 2 ft thick mat at the two stair cores to carry the higher loads imposed by the building’s long spans . This arrangement will also provide additional dead load to resist the overturning and sliding forces imposed by the structural system, says Steve Franckowiak, P.E., S.E., a project engineer for Forefront Structural Engineers, Inc.
Dramatic 30 to 35 ft long cantilevers at either end of the building
will be achieved using full-story vertical trusses. The trusses will
tie into the concrete cores at either end of the building. JGMA
The building will be framed in structural steel, two exposed concrete cores at either end. Structural steel was selected as the primary framing material to achieve the building’s complex geometry, which engineers developed using a combination of two- and three-dimensional modeling. “It became clear in the conceptual design that the architect wanted to create a building that was unusual in its geometry, and by using structural steel, we were able to create the cantilevers and diagrid approach to the framing and optimize the use of material,” says Josh Dortzbach, P.E., S.E., a principal of Forefront Structural Engineers, Inc. “It was also a more effective and cost-efficient solution.”
Several cantilevers will be located throughout the building. The columns along the building’s perimeter will be inboard to afford uninterrupted views into and out of the building and to create the corridors, which will cantilever approximately 9 ft from the slab edge by way of moment connections and steel framing. Those cantilevers will also serve as a counterbalance to the structure’s long back spans. The corridor cantilevers “actually helped us on the structural end as well because they allowed us to achieve a longer span in the back span while still optimizing the framing,” Dortzbach says.
Dramatic 30 to 35 ft long cantilevers will be located at either end of the building. The cantilever on the building’s northeast end will follow the shape of the amphitheater, which is located within the building’s resource room (library). That cantilever will be achieved using full-story vertical trusses, hung like a balcony on the side of the building, Dortzbach notes. Full-story trusses normally require a back span, but because the amphitheater will be adjacent to an open area, a back span could not be incorporated into the space. Instead, the roof and floor structure will become tie struts, transmitting all of the tension and compression loads from the cantilever into the cast-in-place concrete core at each end of the building. “That stair core actually acts as a buttress to prevent the whole end of the building from flipping over,” Dortzbach says. The cantilever on the building’s opposite end will be achieved using a similar approach, tying into the core at that location.
One of the building’s most eye-catching features will be the sunscreen fins that stripe its curtainwall facade. The fins are designed to limit solar gain on the building, which is expected to achieve a gold rating in the U.S. Green Building Council’s Leadership in Energy and Environmental Design program—while also expressing the spirit of the university. One side of the fins will be gold and the other side will be royal blue—NEIU’s colors. The fins will enhance the building’s billboard effect, appearing gold when people drive into the city and blue as they leave the city. “The building takes on a very different feeling from morning inbound to afternoon departure, so within a day’s time you will have experienced both sides of the university, if you will,” Moreno says. “Hopefully, it becomes almost like a movie trailer [and is] enough of a snippet of information to eventually get you to exit that off ramp ... to check out what’s going on with Northeastern.”
Construction of El Centro is well under way, completion anticipated in time for fall classes in September. The building will provide El Centro’s students with a state-of-the-art education center and be a new public face of the university overall. “This visibility will draw our name into the limelight so that we will continue to attract more students in the future to all of our campuses,” Hahs says. “We wanted [a building] that was wonderful, dramatic, a visual of the future, unusual—and we have gotten that. It’s a real sense of celebration.”