spandrel walls and the 1950 Chicago code

I’ve been sitting on this one for just a bit, but having shown off the latest in archival crate-digging to South Dakota State students earlier this week, I think I can roll this out now. (Shout-out to Jessica Garcia-Fritz and Federico Garcia-Lammers, who invited me to speak to their class. They’ve been studying the role of less-celebrated documents–specifications in particular–in the design and construction process–a brilliant piece of pedagogy and a research agenda that’s already paid dividends in terms of understanding how firms like the Guastavino Family actually did business…)

Two years ago I gave a short paper on the difficult passage of Chicago’s 1950 building code, one of the first ‘performance codes’ in the country. It replaced a traditional ‘prescriptive’ code that specified exactly what materials and configuration had to be deployed to meet various fireproofing requirements–so, instead of simply requiring a ‘one-hour’ wall, which modern codes do today, older codes would tell architects and builders to provide, say, a four-inch thick plaster-on-lath wall, or a single-wyth brick wall, etc., etc. Developers of single-family homes and skyscrapers both lobbied for the new approach, since the older code philosophy made it difficult to keep up with innovation–any new material had to pass not only technical advisors, but the entire city council, and many in Chicago (and Washington, which after WWII was working feverishly to address a growing crisis in housing) worked hard to pass more progressive codes that put the burden of approval on independent labs and manufacturers, rather than on political bodies like city councils.

The story of gypsum drywall in all this has been the most illustrative–and I’m happy to say that story (which involves aldermanic corruption and a fistfight on the floor of Chicago’s City Council) will be presented at an upcoming Construction History Congress (fingers crossed). But another aspect of the code change sheds important light on the development of the glass curtain wall in the city, and is of interest for the timing of its implementation–and the construction of one of Chicago’s most iconic high-rises.

Above are excerpts from the 1941 edition of the Chicago Building Code–the final major publication before the change that was approved in 1950. These passages refer to commercial buildings in the central business district, and you can see that they’re textbook ‘prescriptive’ provisions–you have to build the frame out of metal, concrete, or masonry, for instance, and you have a pretty limited palette of materials and configurations that you’re allowed to use where certain fire resistances are required. It’s that last passage, though, that I’m interested in–the requirement for a ‘spandrel wall’ of two-hour fire-resistive construction extending for three feet or more from window to window in any ‘non-combustible’ wall. Two hours is a serious level of fire resistance, met only with brick or concrete. The purpose was to prevent fire from spreading, floor-to-floor, through windows, a legitimate concern but one that was proving less and less valid as a growing body of knowledge about fire spread and suppression led to better and better sprinkler and alarm systems and exiting strategies.

Field Building, Chicago. Graham, Anderson, Probst, and White, 1934.

If you were designing a solid-skinned curtain wall like, say, the Palmolive (1929) or Field Building (1934), this provision made perfect sense–above each floor, you’d simply build a short brick wall that matched the sill height, which you were probably going to do anyway since the formula for building skins at the time was, typically, solid panels with intermittent windows–the code, like many codes, simply followed general practice.

Lever House, NYC. Gordon Bunshaft/SOM, 1951. Digital reconstruction by Saranya Panchaseelan, Paolo Orlando, Shawn Barron, and Nate McKewon

This provision was one that an ace team of grad students and I noticed when we put together the “Deep Plan, Thin Skin” article that appeared in the Journal of the Society of Architectural Historians a couple of years ago–you can see it most clearly, perhaps, in the ‘fictitious’ glass skin of Lever House. Here, dark green spandrels cover a three-foot upstand and a three-foot downstand spandrel wall of brick, which met a similar code requirement in New York’s prescriptive code at the time.

Chicago’s new code, passed in late 1949 and taking effect on Jan. 1, 1950, was authored by a committee led by John Merrill, of Skidmore, Owings, and Merrill fame, and while most of his efforts went toward liberalizing the code for homebuilding (including the contentious provision for drywall that set off the city’s Plasterers’ union…), the new code did include a much more relaxed approach to exterior walls, referring designers to charts with requirements that now allowed exterior, non-bearing walls to be of just one-hour fire resistance if they faced a ‘street or public way’:

Chicago Building Code, 1951 Revision

Crucially, elsewhere in the provisions, one-hour construction could be relaxed further through the provision of windows of unlimited size–again, if the wall faced a public way or street. Quietly, Merrill’s committee had not only eliminated the requirement for the spandrel wall, it had made the floor-to-ceiling glass curtain wall entirely legal as well.

Reporting on the floor-to-ceiling glass of Mies’ largely unheralded 2933 Sheridan Road block, the Tribune noted that it was the “second” tall building to take advantage of this provision, the first being, of course, Mies’ 860-880 Lake Shore Drive. I’ve made that point before, but with some new archival information I think I can suggest that Mies and his office knew about the code provisions (as would most architects in the city at the time).

Building Permit Record Card, 860-880 Lake Shore Drive, Chicago. UIC Libraries/Microfilm.

The code went into effect on Jan. 1, 1950. Above is the building permit card for 860-880 Lake Shore Drive, first filed on Jan. 20, 1950. In other words, nineteen days after the code took effect. That first filing was for a basement permit only–probably about right for three weeks of engineering and drafting. The permit for the actual superstructure came in August–again, matching an eight-month design and documentation period. In other words, once the code was passed and took effect, Mies’ office seems to have rushed out as succinct and compact a set of drawings as they could to get a permit and get work on the site started, and then settling in to design the remainder of the building.

Promontory Apartments (MvdR, 1949) and 860-880 Lake Shore Drive (MvdR, 1952)

The difference this made architecturally was profound, of course. 860-880 was only built three years after Promontory, and it was the change from spandrel to glass wall that made the biggest difference in terms of appearance. Historians often talk about the switch from concrete to steel in the structure, but in reality 860-880 has so much concrete poured around the frame for fireproofing that this made (I think) far less of a difference than the elimination of that upstand brick wall.

Construction Views, Promontory Apts. (L) and 860-880 Lake Shore Drive (R). Architectural Forum.

But to developers–Herbert Greenwald in the case of the Mies buildings, but others throughout Chicago–would have been just as interested in the different construction methods the new code allowed. “Dry” aluminum installation, of factory-assembled units replaced the time- and labor-intensive “wet” brickwork, saving time, weight, man-hours (union man-hours, not to put too fine a point on it) and cleanup.

Jessica and Federico’s class makes the point that hidden documents like specifications or building codes offer all sorts of alternative histories that connect architecture and building to rich networks of industrial, economic, and labor history, among others. There’s lots more to dig into in both the code story and the building permit archives (note, for example, that the permit was applied for by PACE Architects, not Mies…), but this tidbit seems worth getting out there as a small, index-card sized document that reveals far more than its modest size might suggest…

860-880 Lake Shore Drive. Construction Image. Chicago History Museum. Image forms part of the Hedrich Blessing Collection, 1991.0505. All Rights Reserved. Scan from 8×10 BW negative

old chicago skyscraper of the week: harris bank II

Harris Trust and Savings Bank is as old-school as Chicago finance gets–founded in the 1880s, it specialized in municipal bonds and staked its claim on Monroe Street with a 20-story building designed by Boston architects Shepley, Rutan, and Coolidge in 1909-1911. After modernizing in the late 1930s, the bank announced plans in 1954 to expand with a 20-story annex at the back of that tower, fronting on Clark Street.

This was big news–“the first building to be erected inside the Loop in more than 20 years,” claimed Tribune real estate editor Al Chase (pace, Prudential–you’re not in the Loop, you’re Loop-adjacent). Skidmore, Owings, and Merrill were announced as architects, and they produced a sketch of the proposed square tower–an elegant prism up on piloti that reflected their emerging Miesian vocabulary:

(Photo by Kaufman & Fabry, from Al Chase, “Loop to Have New Building of 20 Stories [Harris].”  Chicago Daily Tribune, May 28, 1954.  1.

Inland Steel, of course, grabbed that “first new sksycraper in the Loop in 20 years” crown in 1957, so what happened to Harris Bank’s plans? They ran afoul of the city’s 1942 zoning ordinance, which limited buildings downtown to a volume in cubic feet equal to 144 times its lot size–a bizarre formula that was passed explicitly to ‘limit skyscrapers’ in an era that saw no demand for new commercial space downtown and a growing emphasis on the Loop’s retail development. The owners of Harris’ neighbor on Monroe St., the Fort Dearborn building (a late Jenney and Mundie structure), sued after Harris announced their plans, pointing out that the proposed tower was nearly twice the volume permitted by the code.

Harris may have been counting on the city’s tradition of ‘spot zoning,’ in which a friendly (and, occasionally, well-compensated) alderman would run through a variance allowing a building owner to break the rules in one specific instance, a practice common enough that it had essentially trivialized the city’s zoning code for housing. This contributed to the growing problem of ‘kitchenette’ apartments in the city’s Black belt, in which slumlord owners could easily pack more and more substandard apartments into decaying buildings through political machincations and outright graft.

With a moribund commercial market, however, there had been virtually no spot-zoning in the Loop, but Harris’ plans were thwarted: Chicago’s zoning commission denied their application by a single vote, and the city council actually chastised the company, publicly declaring in March, 1955 that–since Harris rented out the upper floors of its building, the aldermen saw no need for such a tall structure.

It’s hard to imagine that discussion taking place at any other time in the city’s history, but change happened quickly. Just weeks after the city council’s admonishment, Chicago’s new Mayor, Richard J. Daley, took office. Daley saw the Loop as the city’s political and economic heart, and he would take action to not only permit new commercial construction, but to actively promote it as a way of fortifying his political base and slowing the suburban flight that was draining downtown Chicago of its business class.

Harris ultimately took their case to Circuit court, which ruled in their favor in 1956. But by that point the bank’s financial position had improved enough that they reconceived the project, buying the Fort Dearborn building from the owners who had originally blocked their expansion plans and waiting for a new zoning code to take shape. That code, passed with Daley’s enthusiastic backing in 1957, switched from a volume limit to a floor-area-ratio, allowing a 14-story building by right and then providing incentives of additional floor area for amenities like setbacks, colonnades, and sidewalk planting. In July of that year, Harris announced the 23-story building that was ultimately built–just six weeks after the new zoning code took effect.

Harris Bank in an advertisement in Architectural Forum, October, 1961.

Designed by Walter Netsch–after being replaced on the Inland Steel project and finishing design work on the iconic Air Force Academy design–Harris continued some of that building’s themes. While its columns are buried behind its steel-and-glass curtain wall, its mechanical zone is clearly delineated at the 11th and 12th floors, showing Netsch’s continued interest in expressing building services. Harris’ core was integrated with the elevators in the original, 1911 building, giving it a ‘side saddle’ arrangement that SOM’s New York office was pursuing in their design for the Park Avenue headquarters of Pepsi-Cola at roughly the same time.

Typical floor plan of SOM tower (left), Shepley, Rutan, and Coolidge tower (1911, center), and three-story annex (right). “Sophisticated Chicago Skyscraper.”  Architectural Record,  February, 1961.  123-132.

And, about that curtain wall. Like Inland, it’s made of stainless steel, but detailed to eliminate the characteristic ‘oil canning’ that gives Inland’s elevations their shimmering character. Harris’s detailing is all about rigidity, folding thin sheets of steel at their edges to provide a firm edge and prevent the small variations that catch daylight so strikingly at Inland. This gives the wall some greater depth–and notice how Netsch picked up the Miesian trick of regularizing the centerlines of the columns and mullions, with slightly narrower windows at the ends of each bay:

Harris Trust and Savings Bank, Clark and Monroe Sts. Walter Netsch/SOM, 1957-1961. East facade. (photo by the author).
“Sophisticated Chicago Skyscraper.”  Architectural Record,  February, 1961.  123-132.

SOM also designed a renovation program for an adjacent parking garage to the west of the Shepley, Rutan, and Coolidge building to hold a new banking hall and commercial facilities, but this was replaced by a 1972 addition (visible in the background of the lead photo), also by SOM but this time designed by Bruce Graham. That building–a rigorous nine-square grid with expressed girders, greater spans, and an even more robust modeling of its curtain wall–is an essay in the range of design philosophies emergent in the firm, far more in line with the bold structural statement of Sears than with the almost gothic tracery of Harris’ mullions.

elevators (grain) at the skyscraper museum

..virtually, of course. After connectivity and audio issues scotched our planned webinar last night “at” the Skyscraper Museum, Carol Willis has posted my (pre-recorded) lecture on Chicago’s Grain Elevators on their website, along with a generous introduction…those of you who missed out last night, along with anyone else as fascinated by the history of these things as I am, can catch up here:

We’re still on for tomorrow, when UNCC’s Lee Gray will talk about the OTHER kind of elevator, and I’ll join him for a discussion on historic conveying systems in tall structures…of all kinds. See you there…

cans’n’spans

The structures portion of our SCI-TECH sequence is super hands-on, and has become sort of a trademark of the program. While we do cover theory and calculations for basic structural elements, we’ve always felt that building things, testing them, and talking about how real structures are behaving under load is the best way to instill the sort of intuitive understanding of statics and structural form that architects really need when they sit across the table from actual engineers. Rob Whitehead’s structures labs are famous for their large-scale tests, using twenty or fifty pound bags of sand and with everything but walkup music as students turn out to watch big things get broken.

So, how do you get the same haptic learning accomplished in a pandemic? Working with rock star colleague Eric Badding and teaching assistant Anannya Das, we took our long span structures module entirely online this term. Last year we organized it to provide an experimental pathway toward designing a studio-scaled long span–four feet of span, carrying fifteen pounds of load–and asked them to first sketch out ideas, then to build scale models and prototypes before the final test. This year, we scaled it down to kitchen table-size, and asked students to work remotely or in limited numbers in the College’s studios. We restricted materials to just chipboard and hot glue to make it easy to source, and the department funded small jewelers’ scales for groups of two or three students, and we asked them to develop and test structures spanning just 24″ and carrying 16-ounce cans of beans. As a serviceability test, we asked them to roll another can of beans under the span during loading–and the lightest structure to pass that test would earn an automatic 100% for the module.

For the scaled down models, students submitted videos of their tests and .pdfs of sketches or descriptions. But for the final competition yesterday, we got everyone on zoom and asked them to test their models live. Each team had a three minute slot, and we set up a Google Doc so that teams could see when their turn came around so they could be ready to dive right in.

Happy to say that the results were convincing–thanks to good coaching and a diligent timekeeper we saw about 30 long spans carry their cans of beans, and ended up awarding joint first place to projects that did it with 36 and 54 grams of cardboard, respectively–about a 20:1 load/weight ratio. Many of the entries adopted fairly pure structural forms, figured out the secondary and tertiary modes of failure like racking or torsion, and applied the notion of ‘hacking’ shapes to remove dead weight where it did the least amount of work–all themes we tried to emphasize in the long span unit.

And, many of the teams turned out genuinely good looking work–signs that even under the most dire of circumstances good design wins out.

proto-mies I: 2933 Sheridan Road

2933 North Sheridan Road, Chicago. Mies van der Rohe/PACE Associates, 1950-1951.

Among the narrative threads I’m trying to weave together with the postwar Chicago project, the role of high-rise housing is one of the most intriguing–and under-appreciated. Public housing in the city is the most obvious and damning piece of this story, but the role of skyscraper housing in the private sector is also a key element in understanding how and why skyscrapers have been so integral to Chicago’s growth and development.

Developers in Chicago built high-rise housing for the city’s middle and upper-classes consistently through the 1920s, most of it along the lakeshore extending north from downtown and in Hyde Park. New financial instruments–housing cooperatives and, eventually, federally-backed mortgages made high-rise residential towers financially viable and affordable for a broad market. They also exacerbated the city’s entrenched segregationist patterns as they could be exclusionary and targeted toward white neighborhoods at the further expense of desperately overcrowded Black neighborhoods concentrated on the south side. While high-rise co-ops partially democratized the city’s valuable lakefront property, they also set in stone (literally) racial patterns that would define the city’s geography later in the century.

After the war a handful of progressive developers aimed projects squarely at the middle class, taking advantage of city politics that sought–often desperately–to keep as much of the city’s population as it could from moving to the suburbs, in particular its downtown workforce. Among these developers, Herbert Greenwald, a University of Chicago graduate, proved to be a particularly enlightened client. Much more on him to come, but he’s best known as the instigator of Mies van der Rohe’s first (and, arguably, best) high-rise projects–Promontory Apartments on south Lake Shore Drive and their progeny, the iconic 860-880 Lake Shore Drive apartments just north of the Loop.

Promontory is often thought of as a sort of ‘starter-Mies.’ It was Greenwald’s first high-rise, and it was designed in 1947-49 in the midst of an ongoing crisis in the steel industry that limited availability. Its concrete frame is expressed and subtly detailed, but compared to 860-880’s delicate steel tracery it comes across as more plain-spoken and even crude. Nonetheless, Promontory itself was profoundly influential and led to several projects–particularly CHA high-rises–that adopted its exposed concrete and brickwork with admittedly mixed results.

Seeing Promontory as nothing more than a premonition of 860-880, though, ignores the fact that nearly all high-rise housing in Chicago relied on concrete construction. 860-880, for all its influence on American commercial skyscrapers, was a total one-off in terms of its steel construction–a material dead-end in housing that I’m trying to get to the bottom of.

2933 Sheridan Promotional Brochure (Ryerson and Burnham Libraries, Art Institute of Chicago).

2933 Sheridan was designed and constructed almost exactly in parallel with 860-880, and it shows that Mies certainly regarded Promontory as a valid and ongoing experiment. It suffers a bit from a more crowded site–none of the convenient long vistas for photography that have made Promontory a more appetizing subject. But it merits a closer look, both for its clearly targeted demographic–young professionals with and without children–and for the way it developed the exposed, infilled frame that made Promontory such a revolutionary presence on the skyline.

Greenwald’s great genius was catering to urban professionals–young buyers, some with children, who rejected the suburbs and wanted to remain downtown, close to amenities and within a walk or a short drive from the Loop. This demographic was generally well-educated, knowledgable about design trends, and empowered by the postwar economic boom to afford a modest lifestyle boost. The Baldwin-Kingery store, which began selling Scandinavian furniture to young design enthusiasts on Michigan Avenue in 1947, catered to exactly Greenwald’s target audience. In both cases, bringing high design down from the luxury level was a brilliant and profitable endeavor.

2933 Sheridan Promotional Brochure (Ryerson and Burnham Libraries, Art Institute of Chicago).

The building’s promotional brochure featured perspectives far from the precise, almost clinical drawings for which Mies’ office was known, showing instead sketchy, cartoon-like renderings of softly textured carpets and Eames or Saarinen chairs instead of marble surfaces and Barcelona chairs, all looking out over nearby Lincoln Park. Its mix of apartment types–fully 1/3 of which were two-bedroom units designed for small families–reflected the market for apartments suitable for singles, couples, and children.

Most notable, though, to Al Chase, the Tribune’s chief real estate reporter at the time, was 2933 Sheridan’s unique exterior appearance:

“This is the second large apartment project to have windows extending flush from floor to ceiling, thus making the exterior an almost solid sheet of plate glass, broken only by horizontal or spandrel beams and vertical columns, which are of reinforced concrete.”


Al Chase, “Work Started on 244 New Family Units.”  Chicago Daily Tribune, Nov. 25, 1950.  C5.

It was the second apartment building to do so only by a few months–860-880 opened just prior to it. But the combination of floor-to-ceiling glass and exposed concrete edge beams and columns became one of several default formulas for Chicago apartments going forward. If 860-880 was, in fact, a dead-end in terms of the city’s residential high-rises, 2933 Sheridan advanced Promontory’s tectonic formula in a way that was imitated in dozens of high-rise blocks over the next couple of decades–perhaps most clearly in the 1963 Lakefront Place, a 16-story block in South Shore by Schmidt, Garden, & Erikson (who, probably not coincidentally, were then working with Mies’ office on the Federal Center):

Lakefront Place, Chicago. Schmidt, Garden, and Erickson, 1963.

More to come on that status as “second” apartment building to have floor-to-ceiling glass…but for the moment worth pointing out that the various Greenwald projects that seem like they’re warmups for 860-880 had important impacts on their own, and their concrete, brick, and glass solutions proved to be more influential than generally credited…

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

ed allen

No one has had a bigger influence on what I’ve taught and how I’ve taught it than Ed Allen, whose death earlier this month was announced by the Building Technology Educators’ Society last Friday.

As an undergraduate, I had a copy of the first edition of Fundamentals of Building Construction and remember appreciating its patient, explanatory tone. Allen came from a practice background but after making the switch to teaching he took technology pedagogy seriously and his book (six editions later) is now one of a handful of his publications that show up in tech classes and, often, dog-eared and well-loved, on studio desks.

Ed was a key figure in the BTES’ founding in 2006. He was a mentor to dozens of us who, like him, wanted to take what we’d learned as practicing architects and apply it in studios and classrooms. Most of us had technology courses that were separated entirely from design classes–banished to the basement, in grad school–and followed his lead in trying to make tech more design-based and to bring structure, environment, and materials into studio as the vocabulary and grammar that underlay most thoughtful design work. Ed volunteered his time to give our inaugural keynote–I don’t think we could afford to cover his travel, much less pay him an honorarium–and he set the tone for the whole organization as a supportive community that has always shared ideas willingly, kept the bar high for teaching and research, and made time for drinks and dinner after conference sessions.

When we began putting our tech coursework notes together as a textbook in 2004, Building Construction Illustrated was our model. I don’t think we’ve cut into Ed’s sales any great amount, but it’s heartening to see Design-Tech on the shelves as an adjunct to his books–in the same spirit but with a broader focus, and our notes consistently point to his publications for students who want to go deeper. In 2009, when we began overhauling our undergraduate technologies curriculum, Ed flew out to spend three days workshopping with us (we did cover his travel for that), and on his way out he gave us copies of his self-published booklet of aphorisms on teaching and design. I still read from it like a book of zen koans–it’s consistently brilliant and correct about so much. In his honor, two of my favorites:

Design: If you get the form right, the math will follow. Teaching structures as a design discipline rather than an engineering discipline was fundamental to Ed’s pedagogy. Understanding principles, especially why structural shapes are the way they are, is key to good design, and if you understand those and are fluent in them, the calculations are rarely surprising. During my Nervi research I ran across any number of instances where Nervi, essentially, said the same thing. Mathematics are structures’ tactics. Design is the strategy.

Teaching: Your job as a teacher isn’t to cover the material. It’s to uncover a small corner of it and let students’ curiosity lead them to find the rest. Exhaustive lectures covering every possible permutation of structural design, or deriving every single formula, waste time and turn students off. Using that time to go deep on one instance, showing how beautiful the principles behind it are and giving students routes to finding out more turn the tables–instead of us teaching structures, we’re setting up the conditions for students to learn structures, which is more effective–and far more meaningful.

I last saw Ed at the IASS conference in Boston in 2018. As he did with every teacher or architect he met, he remembered me right away and we had a long, warm talk about how our program was doing, the reprint of Nervi’s Aesthetics and Technology in Building that I’d just helped bring out, and a half dozen interesting papers that he’d seen on digital teaching and design. He was in his element, surrounded by people he’d mentored and ideas that challenged him. More than his books and his teaching, that friendly, engaging, and utterly genuine love of the community that he was such a big part of is his great legacy.

Macron, Notre Dame’s spire, Ruskin, and architectural morality

Last week saw the announcement by French president Emmanuel Macron that the spire of Notre Dame is to be rebuilt as an exact replica of the one that was lost in the fire of last April. The announcement was no surprise, given that the French senate ordered that the reconstruction reproduce the “last known visual state” of the cathedral, but it puts to rest any idea of a modern reconstruction.

Such a re-visioning of the lost roof and spire was the subject of more than one ideas competition and a flood of unsolicited proposals from architects worldwide. Many argued–not incorrectly–that the cathedral had evolved over time, even during the Gothic era, to match changing tastes and cultural ideals. Fires had often been cause to rebuild in new styles, and on paper the thought of rebuilding a cathedral using modern materials, or with contemporary concerns at the forefront, seemed like an inspired take. Louis Kahn, after all, famously pointed out that “Beauvais needed the steel we have today.”

On paper this seemed like a fine approach. Online, the results were, perhaps, not contemporary architecture’s finest hour. Spires made of crystal, voluptuous, curved greenhouse roofs, the tongue-in-cheek collages of car parks and fast food restaurants all suggested a rush on the part of designers to use the fire as an avenue for cheap publicity, and few of the ideas drew any public support. The French Senate’s reaction was swift, and welcomed by much of Paris.

The lost spire was not, of course, a Gothic structure; it was built in 1859 to the designs of Eugène Emmanuel Viollet-le-Duc as part of Napoleon III’s campaign to restore monuments damaged in the Revolution or neglected as symbols of the ancien regime. This overlapped with the emperor’s wholesale rebuilding of Paris, which included Hausmann’s boulevards, railway stations, and new commercial and residential sectors, and Viollet-le-Duc’s ‘restorations’ often involved reconfiguring or even re-designing monuments to live up to the Emperor’s ideal of the glorious era of medieval France. Viollet-le-Duc removed and replaced statuary and ornament that had been damaged, but he also replaced or built entirely anew building elements to bring monuments into conformity with contemporary ideals and images of what the Gothic, perhaps, should have looked like.

Notre Dame at the start of the restoration process, in 1847. Photo by Hippolyte Bayard, 1847.

Notre Dame, as it came down to us, was a medieval structure cloaked in a Second Empire vision of the 13th century; Viollet rebuilt the structure’s flying buttresses, removed later additions that had encrusted the base, constructed a wholly new sacristy and topped the crossing with a new, oak and lead spire. There had been a spire on the original church, but it had been removed in the aftermath of the Revolution. Viollet’s version was nearly sixty feet taller than the original and modeled after the later, High Gothic spire at Amiens. It was typical of the campaign to not only restore, but to improve upon the work of the original builders, an approach that is anathema to today’s preservation community but one that, in this case, left the structure with a consistent exterior style and an iconic skyline. Viollet-le-Duc’s restoration is what everyone alive today knows as “Notre Dame,” and the few images of what the cathedral looked like before the restoration have practically disappeared in the torrent of photos, images, selfies, and films of its 19th century incarnation.

So, on one level there’s an intriguing story here about how attitudes circle around, how a modern approach in one century produces a building element that’s seen as both historic and outdated in another, and how preservation is constantly engaged in a debate between fidelity to ‘originals’ on the one hand and a realization that the essence of an historic structure is often dependent entirely on the values and prejudices of the day. But, by odd coincidence, Macron’s announcement came in the middle of my trying to revive a project on John Ruskin, specifically his hastily composed reaction to the opening of the Crystal Palace that was inserted into the first edition of The Stones of Venice as an appendix in 1851. Ruskin, not surprisingly, was not a fan, seeing the structure as transitory, illusory, lacking character, and symbolizing the triumph of industrialization over craft. Such secular optimization, he felt, lacked humanity in its realization and in its experience. He found the displays within to be vulgar and cheap, and the whole enterprise to be a commentary on the hubris and newly sanctioned drive for profit of the era. “Largeness of dimension does not necessarily involve nobleness of design,” he argued, and went on to damn its creator, Joseph Paxton, with the faintest of praise:

“The quantity of bodily industry which that Crystal Palace expresses is very great.  So far it is good.

“The quantity of thought it expresses is, I supposed, a single and very admirable thought of Mr. Paxton’s, probably not a bit brighter than thousands of thoughts which pass through his active and intelligent brain every hour,–that it might be possible to build a greenhouse larger than ever greenhouse was built before.  This thought, and some very ordinary algebra, are as much as all that glass can represent of human intellect.  ‘But one poor half-pennyworth of bread to all this intolerable deal of sack.’ Alas!”


John Ruskin, The Stones of Venice. (New York, P.F. Collier, 1900.) 406-407.

That, alone, is a powerful indictment–the punch line is a quote from Shakespeare’s Richard IV, in which the titular prince complains about the ratio of bread to wine he’s been left with, and Ruskin makes a clear judgment about the lack of architectural nourishment on display versus the intoxicating effects of so much glass and delicate, gymnastic structure.

But, not content to leave the reader with the sense of a tectonic hangover, Ruskin goes on (in this essay and a later one, in 1854) to compare the Palace’s opening with two other cultural moments: the death of painter J.M.W. Turner, in December, 1851, and the very restoration program that would, by the end of the decade, see Viollet-le-Duc’s spire rise over Notre Dame. These, at first glance, are pretty incongruous comparisons. Neither had anything to do with glass houses or industry. But in setting the Palace’s ‘intolerable deal of sack’–it’s vaporous, sensational aesthetics–against the sublime land- and seascapes painted by Turner and the “mathematical” restorations being carried out for Napoleon III, Ruskin was elaborating on one of his great themes–the moral effect of architectural aura. Raised in an evangelical household, his belief in a ‘protestant Gothic’ gradually gave way to a more secular interest–famously, Darwin’s Origin of Species shook his faith and turned his argument toward a more socialist bent after 1858.

But throughout all of his work–religious and otherwise–the interest in art and architecture that imparts a sense of human limits in the face of the divine (or, at least, the infinite) was to Ruskin the key to moral force in all artistic production. Turner’s paintings were paradigm examples of the sublime, in which human scale and ambition is, literally, sublimated to the ravages and scale of nature. The Cathedrals, with their awesome scale, were great theological machines that imparted a similar humility in those struck by their vastness. And the workmanship on those cathedrals, Ruskin felt, was exemplary of human fallibility; he valued the imperfect carving or the marks of tools precisely because they make us recognize the struggle of mortal hands in shaping the raw materials of the earth toward our divine aspirations. In “The Nature of the Gothic,” he makes a clear allusion to Protestant theology:

Do what you can, and confess frankly what you are unable to do ; neither let your effort be shortened for fear of failure, nor your confession silenced for fear of shame. And it is, perhaps, the principal admirableness of the Gothic schools of architecture, that they thus receive the results of the labour of inferior minds; and out of fragments full of imperfection, and betraying that imperfection in every touch, indulgently raise up a stately and unaccusable whole.


Ruskin, “Nature of Gothic,” 185

This confessional tectonic had, for Ruskin, a salutary moral purpose–reminding us of our own imperfection in the eyes of the divine but modeling a project that could drive us closer, at least.

His complaint against the restorations was, essentially, that they were too good–too precise, too mechanical in their reproductions, too finely honed. The resulting monuments lacked the patina of age, and thus the instructive atmosphere of antiquity; they lost (for Ruskin, anyway) much of the temporal sublime that comes with ruins whose vast timescale dwarfs our lifetimes in the same way that the Cathedrals’ scale sublimates our physical dimensions. The “white accuracies of novelty” replacing the decayed and ruined stones in the restorations replaced an aura that conveyed the structures’ very humanity–their soul:

Grant that it can do all this, and that the new building is both equal to the old in beauty, and precisely correspondent to it in detail.  Is it, therefore, altogether worth the old building?  Is the stone carved to-day in their masons’ yards altogether the same in value to the hearts of the French people as that which the eyes of St. Louis saw lifted to its place?  Would a loving daughter, in mere desire for a gaudy dress, ask a jeweler for a bright facsimile of the worn cross which her mother bequeathed to her on her death-bed?—would a thoughtful nation, in mere fondness for splendor of streets, ask its architects to provide for it facsimiles of the temples which for centuries had given joy to its saints, comfort to its mourners, and strength to its chivalry?”


John Ruskin, “The Opening of the Crystal Palace : Considered in Some of its Relations to the Prospects of Art.”  (London: Smith, Elder, & Co., 1854).

The weight–literal and emotional–that old things carry was for Ruskin an important reminder of human limits, an antidote to the blithe hubris represented by the Crystal Palace and to the sensational, short-lived thrills that its insubstantial walls and structure provided. Lingering behind Ruskin’s wrought prose is the sense that the efficiencies and lightness so skillfully developed by Paxton presented a moral danger–architecture as commodity and entertainment rather than as an instructive model of our mortality and our limitations. Lacking character or substance, an industrially produced structure like the Palace might provide momentary pleasure of the senses, as Augustine would have put it, but it can never, as the Cathedrals did, reach our soul through them.

As a fan of both Paxton and Viollet-le-Duc, reading up on this is a bit (*ahem*) sobering. What Ruskin would have made of the current plans to replace Viollet-le-Duc’s spire is an intriguing question–but any moral critique of the fire’s aftermath would no doubt look at the ‘intolerable deal of sack’ generated as ideas for its replacement and seen a clear parallel to the breathless publicity that accompanied the Palace’s opening. One problem with the easy fluency of production is that, while it’s easy to produce intoxicating images, it’s harder and harder to come by genuine nourishment through methods so geared toward the commodification and sensationalism that Ruskin so feared.

Full paper–Chicago’s Grain Elevators, 1838-1957

Santa Fe Elevator, Damen and the Chicago River,

It’s small beer compared to everything else going on in the world today, but I’m pleased to report that “Chicago’s Other Skyscrapers: Grain Elevators and the City, 1838-1957” will be in print in the next issue of the Journal of Urban History and is online now on SAGE Journal’s website (possibly requires registration and/or subscription…the raw version is here on ResearchGate and here on Academia.edu).

This has been a happy rabbit hole over the last five years or so–a chance discovery of a paper on concrete grain elevators from 1902 left me curious about what a non-fireproof elevator might have looked like, and the mention of Chicago engineers’ and contractors’ roles in perfecting both timber and concrete elevator construction led me to dig into the history of elevators in the city. I can’t claim to be the first one to be interested in these–agricultural historian Guy Lee and environmental historian William Cronon have both pointed out the importance of elevators to Chicago and the midwest. But neither of their histories looked at the construction of elevators themselves, and neither presented a comprehensive study of elevator construction and operation during the era.

So, while this has been something of a running joke among colleagues and friends (‘you’re studying what?’ has been a common refrain), the finished paper is one that I’m particularly happy about, because it demonstrates many of the same lessons that Chicago’s ‘real’ skyscrapers have done–that buildings can be thought of as the resultants of complicated networks of economics, finance, politics, and geography (among others), that the actual fabric of building can be interpreted to reveal broader narratives about who built them, where their material came from, and why they were built, and that zooming out and looking at building types over time inevitably suggests that they evolve in a process similar to what Steven Jay Gould called “punctuated equilibrium,” in which long periods of stasis are ‘punctuated’ by moments of rapid adaptation and change–speciation, in the world of paleobiology.

Concrete Elevator construction on the MacDonald System. From the astonishingly comprehensive Milo S. Ketchum, C.E., The Design of Walls, Bins and Grain Elevators.  (2d ed., New York: Engineering News Publishing Company, 1911).

The change from tiber elevator construction to concrete is a clear example of this–nearly every grain elevator in the country before 1900 was built out of timber, and nearly every one after was made of concrete. There are good reasons for this at the macro-level (fire, e.g., meant that elevator builders were constantly looking for ways to build in anything but timber), but it also demonstrates the importance of innovation–three experiments in particular, in Chicago, Indianapolis, and Minneapolis, around the turn of the century provided proof-of-concept, and a patented system of construction (sort of an early version of slip-forming) meant that within ten years it was not only more effective to build out of concrete, it was also cheaper and faster. Instant speciation and the birth of a new, now-ubiquitous type, the concrete elevator.

While this all makes for a great case study in construction history, elevators also, like commercial skyscrapers, tracked the growth and development of Chicago and its infrastructure–but on a larger scale. Their reliance on rail and water connections meant that they sprung up wherever these two transport systems connected–first along the main branch of the River, and then farther south as better rail connections were built to the west. An elevator complex on Goose Island rose in response to rail connections to the particularly rich grain belt of the northwest–Minnesota and the Dakotas. And, finally, when new harbor facilities at Calumet replaced those of the congested main branch, the elevator industry moved, wholesale, to take advantage of better facilities there.

Chicago River, ca. 1890. New York Public Library Digital Collections

So, lots of resonance with familiar themes. And, fortunately, some really fascinating anecdotes that involve corruption, skullduggery, and construction as financial weaponry. Some of the city’s best known figures had unexpected–but, in hindsight, obvious–connections to the elevator industry, in particular meatpacking titan P.D. Armour, who entered the grain trade almost as a hobby and emerged as one of the city’s most feared commodities buccaneers. Elevators and the fortunes they represented also underlay some of the city’s great institutions and monuments, and names from the industry now appear on Chicago landmarks ranging from IIT to Buckingham Fountain and the Art Institute.

An enjoyable ride, in other words. I’m back more or less full time on those ‘other’ skyscrapers now, but this has been a fruitful interlude…


Calumet Terminal Elevator (Armour Grain Co., Chicago and Northwestern), the “largest single unit grain elevator in the world.” 122nd St. and Calumet River. John S. Metcalf, 1917. [Concrete Engineering and Cement World].