rethinking pei

October 5, 2017 § Leave a comment

everson stair viewThis year marks  I.M. Pei’s 100th birthday, and next week I’m taking part in the first half of a trans-pacific celebration of his career.  Pei isn’t totally a new research topic for me–Jason Alread and I wrote about his extraordinary sculpture gallery at the Des Moines Art Center (1966-68) in a 2007 article in the Journal of Architectural Education, and Pei played at least a background role in Kahn’s career, consulting with him on the concrete formwork systems he used for his early high-rises while Kahn was working on the Salk Institute.

So the invitation to contribute to Rethinking Pei’s first session, in Cambridge, MA, was a welcome one, as it has given me an opportunity to dive more deeply in to his work in Des Moines, and also the context to that building, in particular the almost simultaneous Everson Museum of Art in Syracuse (1962-68), New York.  This project started earlier than the one in Des Moines, and it was Pei’s first foray into large scale cultural work after an early career as a strictly development architect.

pei elevation

The Everson was to have been the anchor project to a masterplan for Syracuse’s downtown designed by shopping mall designer Victor Gruen–a masterplan that was never implemented.  Pei, realizing that the museum would have to hold its own while other elements were constructed, created an intentionally closed building–four cantilevered galleries rooted to the ground by circulatory and structural stalks, all rendered in corrugated, rough concrete.  The resulting minimalist sculpture was striking on Syracuse’s admittedly banal downtown urbanscape, and it created a sublime central courtyard, which Pei graced with the first of his many spiral concrete and travertine staircase.

dmac courtyard

Four years later, in the midst of seemingly interminable delays, Pei began work in Des Moines, extending the rambling plan of Eliel and Eero Saarinen’s original limestone building (1946-48) by linking one end of its S-shaped plan with a link between its gallery and education wings.  This was a brave scheme, as it enclosed a much-loved courtyard that had been designed to terminate a long garden axis and rose garden.  But Pei did not so much block this axis as punctuate it.  Through his careful placement of glass and concrete, he ensured that the building was largely transparent along the axis, and that it matched the gradual drop of the site with a double-level gallery.  Again, he used rough-hewn, corrugated concrete as a structural and finish material, all aligned with the original axis and rising to a soaring, butterfly-shaped skylight.

dmac sculpture gallery interior

The conference includes some pretty luminous names–Leslie Robertson, who has always been one of the office’s most valued engineering collaborators, and William Pedersen, of Kohn Pedersen Fox, among them.  There are also a number of academics who will be covering Pei’s extensive career, from the National Council for Atmospheric Research in Boulder to the Louvre Pyramid–possibly the most recognizable piece of postwar architecture on the planet.  I’ve often made the case informally that Pei’s work at the Art Center deserves to be included among his best, and I’m looking forward to making that case in Cambridge next week.  The second half takes place in Hong Kong in December–for better or worse I’ll be listening in by web to that one.

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chicago architecture foundation moving on up…

September 7, 2017 § Leave a comment

Solid news this morning from the Blair Kamin in the Tribune–the Chicago Architecture Foundation is moving from its long-time home in Burnham’s Railway Exchange Building to more spacious and visible digs in 111 E. Wacker. The story reports that CAF will bring its city model with it, along with new models and exhibits on the history of the skyscraper. 111 is part of the Mies-designed Illinois Center (or, really, Mies-office-designed…), and plans call for a new, glass-enclosed gallery that will look out over the docks that serve the world-famous River Cruise. It will also face the Tribune Tower and the new Foster-designed Apple Store, adding to the city’s spiritual crossroads at the Michigan Avenue bridge. Great to see them gaining visibility and emphasizing the connection to their river tour–accept no substitutes!

elevators and infrastructure

August 5, 2017 § 2 Comments

Elisha Otis Demonstrating ElevatorYou can catch me talking about elevators and elevator history with Dr. Joseph Schofer, Professor of Civil Engineering & Transportation and Associate Dean of Northwestern’s McCormick School of Engineering, on the latest episode of The Infrastructure Show, a monthly podcast covering issues of transportation and other systems and networks that make cities and economies go.  Good conversation, and interesting to talk about vertical transportation in a much larger context…

nervi in new hampshire

July 30, 2017 § Leave a comment

c and nerviTechnically on vacation, but part of the travels this month include college visits for my son, who by happy coincidence has Dartmouth on his shortlist.

Hanover, New Hampshire is an unlikely answer to the question of which American city has more Nervi projects than any other, thanks to a progressive campus leadership that commissioned two sports arenas from him in the 1960s and 1970s.  Leverone Field House, finished in 1965, was covered extensively in Aesthetics and Technology in Building, but his second arena, the Rupert Thompson Ice Arena, has never received as much attention.  But as a pair they’re fascinating as a comparison of Nervi’s techniques, literally across the street from one another.

leverone exterior

Leverone Field House reflects an evolution of Nervi’s Turin Exposition Hall–it’s a shallow-vaulted, thin-shell roof supported by ranks of beautifully simple buttresses at its base.  You can see the three-part buttress to the left in the photo, with a diagonal that takes most of the vault’s thrust, a vertical that resolves a portion of the gravity load, and the cantilevered roof that also acts as a horizontal beam, forcing the roof to hold its shape between buttresses.  The main facade has vertical wind braces that are shaped to reflect that they’re primarily bending elements, designed to hold the curtain wall on to the end arch and to its foundations.  A similar system would have stayed the enormous glass facades of the Reynolds Aluminum project, which Nervi had designed a few years prior.

leverone interiorInside, though, the roof is a very different system than the one at Turin.  Instead of that hall’s folded plate construction, Leverone adopted the diamond-shaped lamella pattern of Nervi’s 1939 Orbetello Hangars and the ferrocemento formwork he’d perfected in Rome’s Palazetto dello Sport in 1957.  The result is a fine grain imprinted on a long span, but also an incredibly lightweight concrete roof–the diagonal ribs form both the gravity and the lateral system for the roof, and they ‘trick’ the roof into behaving like a shell with the depth of the ribs, while removing most of the roof’s weight by scooping out the dead weight of the diamond-shaped voids.  It’s a simpler roof than Turin, and the geometry is one-dimensional, so it’s missing the dramatic spirals of the Palazetto.  But it’s still a masterful space (even with all the accouterments of a college athletics facility hanging from it…)

thompson buttress closeThe Thompson Arena (1973-75) wasn’t quite as open as the field house (long story), but its most dramatic elements are on its exterior–these twisting, curving buttresses that collect the thrusts and gravity loads of this arena’s roof into point supports at ground level.  These are trademark Nervi ruled surfaces, using a technique of twisted boards that he’d first worked with on his collaboration with Marcel Breuer at UNESCO in Paris.  Here, the buttresses are paired as they are at the edges of the Scope Arena in Norfolk, which was built from 1968-71.  The concrete on Thompson is similarly flawless–we looked but couldn’t find the nail holes that would have held the twisted boards in place, which are readily apparent on Nervi’s earlier ruled surfaces.  The interior is a similar lamella-patterned set of ribs formed with ferrocemento formwork, but the difference between Laverne’s simple buttresses and these is dramatic.

Both of the Dartmouth buildings are covered well in Alberto Bologna’s book on Nervi’s work in America–in terms of innovation they’re important primarily for the fact that they translated some of Nervi’s most innovative techniques into an American market.  These didn’t prove as economical as they had back home, and the fact that Nervi built only a handful of major projects in the U.S. shows in part how tied to Italy’s unique labor market and material economics.

For me, though, these were vital projects.  Growing up, my grandparents lived just outside of Hanover, and on rainy days while I was staying with them a trip to run around inside Leverone was often on the agenda.  Formative experience, definitely–I’ve said more than once that the Nervi book (due in November, 2017!) is something like forty years in the making…

oakland fire…

July 7, 2017 § Leave a comment

Reading early reports of a massive fire in downtown Oakland at a construction site where 6 stories of apartments were being built.  While there’s no word on the cause yet, a quick Google Maps street view…

Screen Shot 2017-07-07 at 12.34.06 PM

…shows that as of March the building was up a couple of stories.  While the lower level (designed to be retail storefronts) are all obviously reinforced concrete, the upper stories are all lightweight timber with foam insulation.  Those would all get sprinklered, one assumes, but the material itself is not only not fire-resistant, it’s actually flammable.  Hard to tell from the street, but this view doesn’t show anything like fire walls being constructed to separate elements of the whole-block-long site from one another, which would mean that once it starts, there’s not much to start a fire from racing through the light frame construction.

So, all perfectly legal, but a reminder that, as at Grenfell Tower, the gradual retreat in code-world from fire-resistant materials in multi-story buildings isn’t a slam dunk.  Sprinklers save lives, and the latest thoughts on timber high rises all assume heavy, ‘slow burning’ construction instead of the lightweight stuff here.  Still, a sobering reminder that what buildings are made out of can make a huge difference in how they perform in emergencies…

mcmansion hell–this shall not stand!

June 28, 2017 § 3 Comments

Stop press–McMansion Hell, the blog that pointedly and hilariously skewers the worst of American residential construction, has been taken down after Zillow threatened legal action over the use of pictures from its website.  The blog has been required viewing for the last year or so, and it’s done a great job of stretching beyond its original mandate and providing genuinely insightful commentary on and explanations of a huge variety of architectural subjects.

Kate Wagner, the blog’s brilliant author, has promised it will be back up again after she seeks legal counsel, but as many commenters have pointed out, taking content from the web for the purposes of criticism is not just “fair use,” it’s also “fair game.

Want to help support free expression in architectural criticism?  Hit McMansion Hell every so often and send some supporting comments when it does come back up.  And you might also tweet at Zillow.com know what you think of having lawyers send out intimidating letters when someone pokes fun at your target demographic…

cladding and fire

June 25, 2017 § Leave a comment

cladding-720

Mika Grondahl, New York Times

A remarkably good piece in this morning’s New York Times about last week’s fire in Grenfell Tower in London.  The mechanics of the fire were instantly apparent from videos and photos–fires climbing the exterior of a high-rise have become common in the last couple of years, and they’re symptomatic of flammable cladding materials.  Once ignited, polyethylene insulation (in this case) burns quickly, and the heat it generates causes a chimney effect in the confined space between the building structure and the sheets of aluminum or whatever other material forms the outside shell.  Rising air feeds the fire with oxygen, the process accelerates, and if this occurs above the reach of firefighters’ ladders and hoses there is no way to extinguish it.  Two fires in Dubai in 2014 and 2015, and incidents in Scotland, Australia, and the U.S. have all demonstrated the same fire behavior, and making the exterior skin of a building fire resistant, or at least incombustible, has always been an important element of building codes.  It’s life safety 101.

Alcoa detail

Shawn Barron and Saranya Panchaseelan, ISU CHiRG

We’ve actually been looking at similar details in postwar building skins this year in our research group, and one building in particular stands out as an example of how thin metal skins should be composed for fire resistance.  The Alcoa Building in Pittsburgh (1953) pioneered the use of sheet aluminum as a cladding material, installed over a concrete-covered steel structural frame.  If you look closely at the digital model, you can see that the  floor plate hits a vertical band of metal panels (stamped with an “x” shape) that are backed up by solid precast panels.  These panels stick up and down from the edge of the floor, and they’re designed specifically to keep fire from spreading from one floor to the other.  Any insulation is on the interior of the panels, and the space between those panels and the aluminum skin itself is broken up by firestops at the floor levels (and by the window frames).

Code requirements for those upstand and down stand fireproof panels were seen as pretty conservative in the 1950s, and in fact Inland Steel in Chicago was among the first projects to get around the typical understanding of even a glass curtain wall as a plane of solid, fire-resistant material punched by glass windows.  Inland got away with a lot, including exiting requirements, but its curtain wall passed muster by reducing the fireproof panels to simple spandrel covers that extend only over the depth of the building’s edge girders.  While codes relaxed considerably, allowing cladding systems that wouldn’t necessarily have stopped a fire, this came in an era when other technologies–building sprinklers in particular–came along that could have.  Provisions to prevent the building skin from contributing to a fire included requirements that the exterior materials be at least fire resistant, and that cladding systems include firestops–horizontal bands of fire- and smoke-proof material that would keep fire from spreading up through voids within the curtain wall.

We often talk in tech classes about how difficult it is, in today’s regulatory environment, to get a really serious building fire going.  Codes have developed into good balances of conservative practice and common sense.  Sprinklers activate when a fire is detected, and the size and composition of spaces are calibrated to contain fires for at least an hour–and in some cases up to four.  Meanwhile, all building spaces with a population of over 50 are supposed to have two exits, so that occupants’ routes aren’t blocked, and alarms and fire drills are supposed to notify anyone in a burning building, and to give them an intuitive sense of what a safe route out of the building should be.  People complain about the onerous requirements of codes, and they resent the time and disruption of fire drills, but put together these represent advancements in life safety that rival, say, vaccinations for the positive impact they’ve had.  People simply hadn’t been killed in high rise fires in jurisdictions that had up-do-date codes for decades.  When this did happen–as in the Brunswick fire in Chicago in 2003–it usually highlights shortcomings in the code.  (In that case, the building had been grandfathered in and had no sprinklers–an oversight that remains a problem in Chicago).

So, what went wrong at Grenfell?  In a word, everything.  The tower had been re-clad recently, and anti-regulatory sentiment had moved the U.K. and local governments to devolve enforcement of fire codes to a form of ‘self-policing.’  A financially strapped contractor made a substitution to the original specs for fire-resistant insulation, which is more expensive.  The tower itself was originally built in an era of fiscal austerity and a desperate need for new housing,  and inattention to basic exiting principles meant that the tower had a single staircase.  Worse, residents had been instructed to remain in place on the upper floors in the event of a fire alarm–good advice for a typical building fire, which spreads from the inside out, assuming that walls and doors have proper fire resistance.  But, in this case, residents would have been better off evacuating away from the inferno taking place on the exterior, and toward the relative safety of the interior stair.

The blame here is stunningly obvious, and various activists have pointed out that collusion–inadvertent or not–between politicians promising to “cut red tape” and industry suppliers, installers, and contractors seeking to provide the cheapest possible alternatives led in this case to consequences that, given the cladding fires of 2014-2015, should have been readily apparent.  Particularly galling is the culpability of Arconic, the supplier of the flammable cladding system.  Arconic is the re-branded name of Alcoa, the Aluminum Company of America, whose metal-clad headquarters were built in 1953 with proper fire-resistant principles in mind.  Their marketing materials for the system installed on Grenfell suggested that it was an inappropriate choice for high rises because of this danger, but in Britain this was tempered with a phrase deferring to local building codes.

If, as in this case, those codes have been decimated by political maneuvers to ease the profit-making of the building industry at the expense of the citizens living in proximity to such bureaucratic indifference to human life, then even the supplier has to bear ethical and moral culpability for this disaster.