cal lewis

An immeasurably sad week.  Iowa has lost one of its great architects, and many of us have lost a great friend and mentor.  Cal Lewis, who had been a partner in the Des Moines firm HLKB and then department chair at Iowa State for ten years, died Saturday. He’s left a legacy of buildings in Des Moines and throughout the state–many that he designed, many that he subtly influenced, encouraged, or nurtured into being through his quiet persistence and vision.  But more importantly, the people he supported, taught, and encouraged, during his career have gone on to found dedicated practices, to design thoughtful spaces and buildings, and to pass on his caring, challenging studio teaching.

Cal began his chairmanship the week I arrived at Iowa State, in 2000, and he was patient and supportive while I found my feet in academia.  (Years later he would admit to me that he was finding his as well).  He championed young faculty, finding ways for us to present at four or five conferences a year, realizing that exposure like that was important for our careers and for a program trying to make its mark nationally.  He and I shared a basement studio space in the College for three years, where I learned the craft of teaching from him and we convinced students that being hidden away gave us the advantage that no one knew what we were up to.  And, last year, Cal volunteered to nominate me for AIA Fellowship.  Joining him in the College of Fellows was a distinct honor, and the extra letter after my name is one of dozens of reminders of a career and a life that truly made a difference.

hancock elevator “plunge?”


hancock sofitel

Juicy story yesterday about the failure of an elevator cable in the John Hancock Tower’s 96th floor express shaft. According to the Tribune:

On the return trip, the elevator started going down faster than they were expecting, said one of the students, who didn’t want her name used for privacy reasons.

“It was really bumpy — it felt like a flight into Chicago,” she said.

Married couple Jaime and Maña Montemayor of Mexico City were on a business trip and had just finished dinner with a large group. After getting in the elevator they suddenly heard a loud “clack clack clack clack clack,” said Jaime Montemayor, 50.

Then dust particles began seeping into the elevator, and they panicked. “I knew something wasn’t OK,” said Maña Montemayor, 49.

Initial press coverage talked about the elevator “plunging” 84 floors, finally becoming stuck between the 11th and 12th floors, and the fact that the elevator was in a “blind shaft,” meaning firefighters had to cut through “concrete walls” to access the cab.

Scary stuff if you’re stuck in the cab, for sure.  And some commenters have noted that safety brakes should have engaged if the elevator did, in fact, ‘plunge.’  But I think there’s a slightly more benign explanation, especially given some confusion about the sequence of events.

The express elevators in the Hancock are fast–really fast–1,800 fpm, which makes them as speedy as any others in the U.S.  The ride down, especially for those on their first trip, is pretty dramatic and, frankly, bumpy.  And its elevators, like every other one in the U.S., has multiple hoisting cables, designed to ensure that, if one fails, there’s plenty of redundancy.

The Washington Post’s version of the story gets the timing a bit different:

It whizzed past all the usual stops, falling and falling and falling 84 floors before coming to an abrupt stop somewhere between the 11th and the 12th.

Then came the dust and dirt, floating into the elevator from the ceiling.

And then came the panic.

If that’s accurate, then it’s entirely possible that nothing went wrong until the cable failed.  The safety brakes may have engaged then–or, alternatively, since there would have been plenty of redundancy, it’s possible that the elevator never exceeded its safe travel speed, and only got jammed when the snapped cable ended up getting snagged in the guide rails.  A falling cable is a pretty grave hazard, but the “clack clack clack” jibes with the loose end banging against the other, remaining cables as it fell.

Once the elevator was stuck, getting the passengers out was a definite problem.  Express elevators typically are placed in ‘blind shafts’ that bypass floors they don’t serve.  Every elevator door costs roughly the same as a small car, so if there’s no reason for the elevator to stop on, say, the garage floor on 11, there’s no reason to spend the money.  My initial thought was that the ‘concrete’ that firefighters had to dig through may have been a shear wall, which would be a pretty heroic job, but Chicago Fire Department photos show that it was actually a concrete masonry wall–not structural, and not reinforced–that they had to get through:

Screen Shot 2018-11-19 at 8.31.40 AM

All of that is scary enough, especially if you’re the one trapped in the cab for 2-3 hours.  But, as often happens, the press coverage veered pretty quickly toward the sensational.  A cable snapping in a high-rise elevator is a vanishingly rare occurrence, whereas a century ago this happened with alarming regularity–and universally fatal consequences.    It’ll be interesting to see what the final report on the incident says, but if, in fact, the above scenario plays out then the fact that no one was even hurt–and that an event like this is so unusual–speaks to just how safe modern (or, even, half-century-old) elevators are.

encoding design

Looks promising, doesn’t it?1951 code cover

In Chicago for this weekend’s Chicago Design Conference at the Art Institute, presenting a rabbit-hole of research on Chicago’s 1951 Building Code, which is a great story about how political and economic considerations end up being imprinted–literally ‘encoded’–into buildings through these documents.

The city’s code through WWII had been a ‘specifications’ code, one that held architects and builders to strictly defined materials and dimensions depending on the level of fire resistance a building type and location demanded. This worked well for an era where brick, concrete, stone, plaster, and terra cotta were pretty much the only materials being considered for building exteriors and walls.  But technical developments in the 1930s and, especially, during the war meant that the code left a lot of innovation on the table, with no way for designers to take advantage of new materials like, say, aluminum in skyscraper construction.  Or new production techniques like gypsum drywall in residences.

John O. Merrill was the choice of a coalition of civic leaders to put a new code together.  They had hired the John Pierce Foundation to prepare a study of new types of building code, and the Foundation was familiar with Merrill’s work on the extensive housing constructed for Oak Ridge, Tennessee–which because of wartime exigencies had been largely unregulated and, therefore, particularly innovative.  Merrill and his team put a draft code together in 1948, and it spent two years in limbo as building trades, manufacturers, developers, and politicians argued over its merits.

The full story is in  the conference paper here, but suffice to say that the proposed code served as a lightning rod for everyone who had a stake in the changing nature of high-rise and domestic construction.  Labor-saving technologies like drywall drew the ire of tradesmen and their unions, who used fears about fire to bolster their arguments against such threats.  Developers and other trades–in particular carpenters, who stood to benefit from relaxed standards for frame construction–lined up in favor of Merrill’s code.  Ultimately, after controversies, an underhanded attempt to sneak 25 amendments in without the public noticing, and a brokered compromise by new reformer mayor Martin Kennelly, the code passed on New Year’s Eve, 1949.

Among other things, the new code’s relaxed standards eliminated tight specifications for spandrel walls in high-rise construction.  The old code had dictated upstand walls between windows, assuming that all skyscrapers would have more or less solid skins with punched windows:

“Every window in a non-combustible wall shall have a non-combustible sill and spandrel wall equivalent in fire-resistive value to two-hour fire-resistive construction for a vertical distance not less than three feet between such opening and any opening in the story next below such opening.”

The new code required structural elements to maintain a three-hour fire rating, but loopholes in definitions and classifications left no such requirements for the remaining territory of any non-bearing exterior wall that faced a street or a court.

The result can best be seen in Mies van der Rohe’s first two projects for developer Herbert Greenwals–Promontory, which was completed in 1949 to the old code’s spandrel standards, and 860-880 Lake Shore Drive, which was permitted after the new code took effect, and which took notable advantage of the newly-freed exterior wall:

Encoding Design Slides Nov 2018 Promontory 860.001

The code linked construction downtown and development further afield in balancing concerns for safety with innovation and the political power of unions and developers against one another.  As such, it’s one of several precursors I’m looking at in trying to figure out how innovative high rise construction took root in the city some twenty years after development ground to a halt during the Depression.  Codes are always political documents, but this episode illustrates this brilliantly.

Thanks to colleague and office-mate Andrew Gleeson for pointing me in the direction of numerous assessments of Promontory’s spandrels–theories on them have ranged from lack of steel to a conservative building culture, but the impact of the code’s restrictions seems to be a new piece to add to the puzzle.

APTWGLC and CHSA joint symposium in Chicago, 17 May 2019

blackstone-hotel-1909Couldn’t be happier about this–two great organizations joining forces to spend a day talking about old structures, how they were built, and how to make sure we keep them around.  Please consider submitting an abstract–the list of potential topics is wide open, and we’re always keen to hear from new voices and to discover new topics.

Call for Abstracts




Preservation of Industrial Archaeology and its Construction History


Friday, May 17, 2019

Program:  8:00 am – 4:00 pm

Reception: 4:00 pm – 5:00 pm


School of the Art Institute of Chicago’s Ballroom

112 S. Michigan Ave. Chicago, IL


The Association of Preservation Technology, Western Great Lakes Chapter (APT WGLC) and the Construction History Society of America (CHSA) invite interested parties to submit abstracts for presentations to be considered for the joint 2019 Symposium on the theme:Preservation of Industrial Archaeology and its Construction History.  The program will offer a single track, intermingling the two disciplines of preservation technology and construction history with a scientific committee composed of members from APT WGLC and CHSA.

Abstracts focusing on subjects related to industrial construction during the 19th C. in the mid-west are encouraged such as:

–  Mill design and construction

– Fireproofing options for industrial buildings

– Lighting solutions prior to electricity

– Industrial power sources

– Railroad construction in the area

–  Iron & steel manufacturing innovations

– Evolution of industrial structural design

–  Canals, waterways and Great Lakes transportation

– Incorporating historic industrially zoned sites with modern approaches to urban planning

– Challenges of preserving industrial sites and buildings

– Interpreting historic equipment in a modern reuse of an industrial site

– Archaeology at an industrial site – how discoveries inform design

– Abatement of archaeological sites


Professional presentations (including five minutes for Q&A) should be 20 minutes, while Student presentations should be 10 minutes. See below for further submission clarifications.

Abstracts for Professional presentations should be no more than 4000 characters and should include:

  • Title of presentation
  • Author’s name & contact information (include title and/or credentials as preferred for publication)
  • 200 word or less biographical statement (for speaker introductions)

Abstracts for Student presentations should be no more than 4000 characters and should include:

  • Title of presentation/research study
  • Student Name, University & contact info (include title and/or credentials preferred for publication)
  • 200 word or less statement of future professional or research interest (for speaker introductions)

All abstracts should be submitted via EasyChair –


Deadlines and notification dates will be:

  • Deadline to submit:January 7, 2019
  • Author NotificationJanuary 25, 2019
  • Speaker Registration DeadlineFebruary 8, 2019
  • Presentation submission:April 17, 2019
  • SymposiumMay 17, 2019


Presenters are not required to be members of APT WGLC or CHSA. Each accepted abstract will receive discounted conference registration for one Member-presenter. Discounted registration will be provided for a second Member presenter and Non-member presenters.

Accepted abstracts will be published on APT WGLC and CHSA websites. Submission of an abstract implies agreement that if accepted the abstract may be posted on said websites or other symposium marketing materials.

For more information, please visit:

Should you have questions regarding this call for abstracts, please email the APT WGLC board at or CHSA at