pei’s proto-tube structures

Inspired by Lee Bey’s Southern Exposure, which celebrates the often-ignored architecture of Chicago’s South Side, my weekend mornings have involved skyscraper scavenger hunts to find some of the city’s tall buildings that have never made the canonical history books. Most of these are residential blocks–some public housing, but also numerous developer towers that extend and complicate the tidy narratives of downtown’s commercial architecture.

Several of those to come, but this morning I turned inland through Hyde Park to zip past I.M. Pei’s University Apartments from 1961. These are well known for the way they sit in the middle of 55th Street and for their role in the infamous plan to “renew” the neighborhood around the University of Chicago. Those are both well-traveled tales, but I have a parallel interest in them that’s actually tied directly to those more celebrated towers downtown…

One of the best known stories of postwar Chicago is the development of the tube structure by Fazlur Khan and a team of engineers and architects at Skidmore, Owings, and Merrill. Khan recognized that beyond 35-40 stories, a skyscraper is most efficient if it’s thought of as a giant column, subject to all kinds of random bending and buckling loads from wind. The theoretically ideal shape for a tall column is a hollow cylinder–a tube–and Khan realized that by concentrating a skyscraper’s structure around the perimeter, he could take advantage of this principle on a large scale. The results were towers like the Brunswick, which distilled its structure into dozens of small columns around the exterior, all fixed to deep spandrel girders and thus working together as four giant (but heavily perforated) shear walls.

SOM | Brunswick Building
Brunswick Building, Dearborn and Washington Sts. SOM, 1965 (Skidmore, Owings, and Merrill)

But, like any other structural innovation, the Brunswick didn’t come from nowhere, and Hal Iyengar, one of Khan’s trusted engineers, recalled later that the idea for stiff perimeter connections and oversized columns that would approximate a hollow tube structure had played a role in engineering the Equitable Building, at Michigan Avenue and the River, in 1963-65.

Brunswick Building, Dearborn and Washington Sts. SOM, 1965 Typical Floor Plan showing Perimeter Structure. (Skidmore, Owings, and Merrill)

But even that idea seems to have come from somewhere else–New York, to be exact. Concentrating structure around the perimeter means, necessarily, that the 19th century fight between windows and structure was back on, and the compression of window wall and bearing structure into a single plane was employed by I.M. Pei on two projects in 1961–Kips Bay Plaza Apartments in New York, and Hyde Park’s University Apartments. These were both mid-rise buildings, but they were significant for the way their structures suggested a return to exterior bearing walls, albeit ones with wildly different proportions since they were made of reinforced concrete instead of simple masonry. Such a circling back to bearing wall construction was lost on many, including the New York Times’ Glenn Fowler, who reported on the two projects as:

Kips Bay Plaza, I.M. Pei & Associates, 1963. Typical floor plan showing perimeter structural walls. (Pei, Cobb, Freed).

“…a new method of concrete construction, in which the facade of a building serves as its supporting framework…”

Glenn Fowler, “Facade of Building Forms Structural Support for High-Rise Apartments:  New York Times, Apr 23, 1961, pp. 449.

Bruce Graham, interviewed for the Art Institute of Chicago’s Oral History Project, recalled that the Brunswick wasn’t as innovative as it was made out to be–“the idea of the tube was not ours. It was taken from a building by Pei in New York,” he told her, and even Chicago partisan Carl Condit acknowledged, in 1964, that the concrete tube had originated with Pei:

“…the Brunswick is the largest building to date with external bearing walls of rigid-frame concrete trusses (also known as load-bearing screen walls and window truss walls).  A wall of this kind is the most recent structural innovation in multi-story American building but it springs from a long and complex history….It was first adapted to the construction of entire building walls by the architect I. M. Pei in the design of two apartment groups built in 1959-61 in New York and Chicago: the Kips Bay Plaza Apartments in New York and the University Apartments on 55th Street in Hyde Park.  Loewenberg and Loewenberg were the associated architects on the latter buildings.”


Carl W. Condit, “The New Architecture of Chicago.”  Chicago Review, 17:2/3, special issue on New Chicago Writing and Art.  1964.  11

University Apartments, 55th St., Chicago. I.M. Pei & Associates. Partial typical (top) and ground (bottom) floors showing tightly spaced columns around perimeter. (Architectural Record, April, 1962).

Much more on those associated architects in a future post–but what’s most interesting to me about Condit’s reporting is that Kips Bay was actually finished in 1963, while the University Apartments–on SOM’s doorstep–were finished in 1961, just as the Brunswick was being announced. While University apartments are also mid-rise–at 470 feet long and just 94 feet tall, they’re the ultimate groundscrapers–it’s easy to imagine the construction site being of particular interest to Khan, Graham, and the other designers contemplating a high-rise concrete structure and primed by their experience on the Equitable to be thinking of exterior structures.

University Apartments, 55th St., Chicago. I.M. Pei & Associates. Exterior view with detail of concrete bearing wall. (Architectural Record, April, 1962).

Things get even more interesting, though, when you dive into University Apartments’ engineering, because the structural engineer for the project was August Komendant, better known for his work with Louis Kahn and, at the time, New York’s premiere concrete engineer. Komendant and Pei developed a styrofoam forming system for University Apartments that produced super-smooth finishes–a technique not dissimilar to that adopted last year by SOM for their Stereoform Slab project. And two years after University Apartments, when Kips Bay was being completed and Kahn was struggling with mixtures and formwork on the Salk Institute in the summer of 1963, he had Komendant approach Pei for advice, and Pei generously shared his office’s concrete specs. While its local legacy is a decidedly mixed one, University Apartments’ more subtle influences were widespread…

hospitality design student awards sweep (again…)

Hang Gao, Wan Wei, Zhuoqi Xu, and Tianling Xu

Word this week that Hospitality Design’s student awards this year were–again–a clean sweep. Iowa State’s interdisciplinary Paris studio, which proposed a mid-range convention and tourist hotel on the site of an aging sports center in the Grenelle neighborhood took both finalist spots. Lee Cagley, ISU’s Interior Design Chair, and I have taught a studio that puts interior designers, architects, and landscape architects onto teams and gives them an impossible program on an intimidating site–after two years in Panama City, Panama, we moved the site to Paris and took advantage of ISU’s study abroad policies to spend a week there in January, 2019. Student teams were, obviously, inspired by the day-long “death by Corb” walking tour and, perhaps, by other stuff in Paris–the work from that studio was stellar, as reflected by the second sweep of the HD awards by ISU teams.

Nastassja Degarmo, Grant Bauermeister, Colton Howell, and Mark Ramirez

This studio is, hands-down, as much fun as you can have teaching. Students slowly get used to the subtly different sets of values that each discipline brings to their team, and once things start rolling the complementary knowledge that they’ve acquired over their three or four years in design school can meld in interesting ways. Lee and I think the studio is successful when we see landscape architects arguing about carpet patterns, or interior designers figuring out a curtain wall detail, or architects drawing (gasp) trees.

Hang Gao, Wan Wei, Zhuoqi Xu, and Tianling Xu

Lee and I thought that any one of a handful of teams could have easily taken one of the top prizes, but the two that did win, shown here, did a remarkable job of weaving together a structurally diverse set of program elements into efficient but wildly expressive forms that contained rich, evocative spaces. They both embodied the studio’s premise, which is that the collision of interests and values that occurs when young designers come to a project with as much curiosity as energy usually results in projects that are solid in many, many dimensions. Glad to see the jury thought so, too.

Oh, and if you think these are good, wait until last spring’s Honolulu studio sweeps next year’s awards, because holy smokes.

Hang Gao, Wan Wei, Zhuoqi Xu, and Tianling Xu