January 15, 2013

Perot Museum of Nature and Scienc

“Forceful,” “acrobatic,” “muscular,” “raw,” even “gritty” are usually the operative adjectives to describe the architecture of Thom Mayne (2013 AIA Gold Medalist) and his firm, Morphosis. But not “refined.” Yet the Perot Museum of Nature and Science, which opened in Dallas last month, seems surprisingly restrained for a building by the Los Angeles firm. With its pale, crinkly precast-concrete panels enclosing a cubic volume, it appears rather sedate from afar. At the same time, there is a raw energy in the way the calm cube erupts from a craggy free-form plinth covered with shards of rock and local plants.

While the cube and plinth provide the dominant volumetric elements, the skin brings the exterior into high relief. Riddled by wrinkles, creases, and puckers, the precast-concrete cladding would look like an elephant's hide if it were not so light in color. Instead, the slightly mottled off-white surface has a ruched texture like a luxuriantly pliable fabric. The heavy cloak of 656 precast panels, typically 8 by 30 feet (and some weighing 16,000 pounds and up to 9½ inches thick), gives the striated skin arresting shadow lines, a coup de théâtre made possible by the architects, the engineers, and a concrete subcontractor using building-information modeling (BIM).

The Perot cube did not come all that naturally to Mayne. His first scheme, an angular, hunkering form, extended over much of the 4.7-acre site, and its galleries adopted the splayed shapes of the container itself. But the client, Mayne found, “felt more of a comfort level with neutral stacked exhibition spaces and not too much light.” And terms such as “orthogonal” and “opaque” seemed key to understanding the museum's vision.

Mayne's response was a 170-foot-high building containing four floors inside an almost blank cube devoted primarily to windowless galleries. Three design firms (Amaze Design, Paul Bernhard Exhibit Design, and Science Museum of Minnesota) took over installations for the 11 permanent exhibition halls, focusing on fossils, birds, geology, space exploration, and other topics.

Children's classrooms and exhibition areas occupy the plinth's lower level, which visitors can enter from the east, where the architect's geological formation seems pushed up by a glacial flow of curtain wall. The glassed-in main lobby, a void separating the cube and plinth, is reached by visitors ascending a curved ramp from the parking area to the west.

In order to bring daylight into the museum, Mayne cracked open the southeast corner of the cube to create a glass-and-steel atrium containing escalators and staircases. He made the museum's major circulation device—the escalator—a salient feature of the exterior by enclosing a 54-foot-long section of it in a glass cartridge smacked onto the south facade. The exposed escalator is the final move in a sequence that begins at the lobby level; where it pushes out, the cartridge is cantilevered from a beam that in turn is cantilevered from another beam. These acrobatics control deflections and vibrations, notes structural engineer Kurt Clandening of John A. Martin & Associates, which worked with Datum Engineers on the project.

Daylight floods the cube's atrium and dramatizes the sculptural pyrotechnics: Here a precast-concrete curvilinear vertical assemblage, suspended from the roof, alternately narrows and widens into a tornado-like whorl to embrace staircases and escalators. Nearby a poured-in-place-concrete shaft contains glass elevators for those who succumb to vertigo in glancing over perforated powder-coated aluminum balustrades or by peering down 99 feet through the metal grate floor of the fourth-floor bridge.

The escalators only go up. Visitors are encouraged to start at the top, where an 85-foot-long dinosaur's skeleton (a reconstructed Alamosaurus incorporating actual vertebra fossils) charges through a 36-foot-high space on the fourth floor; large concrete Vierendeel trusses on the floor above allow the dinosaur to have sufficient headroom.

Lower down, where the cube seems to hover above the lobby level on the plinth, large V-shaped concrete columns supplement a grid of round concrete ones, and transfer girders adjust loads at the perimeter. In this light-filled space, a limpidly curving glazed wall relies on a tension-cable-supported system to stabilize its organic flow. The lobby's mesh ceiling partially conceals the concrete deck above and carries slender rods of LEDs. In addition, polygonal fiberglass pods—similar to those resting on the exterior landscape of the plinth's roof—nestle against the ceiling, emitting light through small perforations.

Mayne wanted the building to function as its own scientific exhibition as well as a provocative work of architecture.Accordingly, the museum design includes various sustainable features: Rainwater rolls down the slanted roof into two cisterns (with minimal drainpipes), which recycle up to 50,000 gallons for irrigation and flushing. Three solar collectors on the plinth roof help heat water, and most of the concrete in the project uses fly ash, slag, and other supplementary cementitious materials to reduce the carbon footprint. Since the precast panels cover most of the cube, the heat load is cut down as well—all of which will keep operating costs down for the $185 million museum.

Mayne won the commission over architects Ennead, Shigeru Ban, and Snøhetta, though he had not designed a museum before. It was a first new building for the client as well. The museum's contents came from three different collections exhibited at Fair Park in Dallas, built for the 1936 Texas Centennial Exposition. Nicole Small, the CEO of the Perot, says Mayne “understood the building could be a teaching tool. The way he thinks about sustainability and materials is creative and rigorous.”

With its Cartesian cube and its free-flowing, lavalike plinth, the Perot museum is one of Morphosis's most remarkable works to date. Like James Stirling's architecturally synoptic Neue Staatsgalerie in Stuttgart (1984)—“my model,” Mayne notes—the Perot combines traditional roomlike galleries with unconventional halls. It also mixes Euclidean geometry with hyperbolic curves, and juxtaposes fluid and restrained spaces. The striking design evokes the naturally sheared cube of black pyrite from Spain on view in the museum's Lyda Hill Gems and Mineral Hall. The connection between natural and man-made artifact speaks of a flinty integrity that makes architecture meaningful.

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