Three hours west of Chicago, Iowa isn't traditionally thought of for its architecture, but the state has a long tradition of excellent buildings by architects ranging from Louis Sullivan to Saarinen pere and fils, and more recently to David Chipperfield and Frank Gehry. Steven Holl's new building for the University of Iowa's School of Art and Art History continues this tradition, settling in to a complex, riverfront campus and using steel to define programmatic, formal, and contextual volumes in profound and engaging ways.
The University's art campus is separated from its main academic center by the Iowa River; it has grown up somewhat chaotically around large stretches of parking. Holl was originally given the commission to extend the Art School on an open site some distance up the road from the original 1930s building, but after seeing the site asked if the location could be moved closer to the existing buildng, to a 'leftove' site at the foot of a large bluff and adjacent to an abandoned quarry. Holl Associate Chris McVoy recalls that this site was both more challenging and more meaningful, as it offered an opportunity to explore the meeting of the campus\' grid layout with geological forms.
This site demanded a scheme that could inflect along pedestrian routes to the art school, to the University-related neighborhood atop the bluffs, and to a nearby pedestrian bridge. While a simple addition to the older structure would have suggested a 'object' building, this site required one that acted as a field through which movement could occur, which neatly paralleled Holl's longstanding interest in what he terms 'porosit'. Recent work exploring this notion, including his dormitory at MIT, adopted a more metaphorical interpretation of this idea; at Iowa, Holl was able to design a building that was permeable in experience as well. Early experiments moved programmatic elements – a library, classrooms, studios, and offices – around the site to find ways in which their layout could reinforce and strengthen movement across and through the site, and these resulting voids and paths became the building\'s key generators.
The resulting forms play off of the site's unusual geometry. One element clings to the curved prow of the bluff, extending its mass toward the north and housing offices and small classrooms on the ground level, library and office space on the second, and studios on the third. The southern edge of this form opens up on to the quarry with public and reading space, while the northern edge houses programs needing soft, diffused light, which comes through translucent glass in a more urban façade. Toward the old art school, a bulging volume houses the main auditorium and a design studio while sheltering the building\'s main entrance. Finally, the most dramatic form is a long, cantilevered volume that shoots out from the second floor over the quarry, containing library and multimedia functions while forming a dramatic signature to pedestrians and drivers alike arriving from the south. These three forms intersect and overlap in a central void space that merges and blurs their interior boundaries. The spatial overlap here supports an intended programmatic overlap between the varied functions, and a cafe here forms the social core of the building and, by extension, the art campus.
The Holl studio\'s early studies explored the possibilities of defining volumes with planes, opening corners, edges, and surfaces to emphasize the distinctions between a suggested form and an experienced void. Overlapping, sliding planes could open up views and access to the landscape – in particular the quarry – but these also began to play a role in shaping the central \'community forum\'. Heavy structural steel played a provocative role in achieving the sense of permeability suggested by the massing. Holl\'s watercolor sketches show an interest in exposed edges, and in thin, tenacious planes of plate steel thoughtfully exposed. These became touchstones for a vocabulary of planar forms defining the programmatic voids and shapes that arose from the earlier design phase. On the exterior, this metallic investigation is manifested in a unique cladding system of weathering steel.
Richer in tone than Cor-Ten, this alloy quickly oxidized to a rich, orange-red that recalls the brick of nearby campus buildings. Contrasted with concrete structural elements and glass, the steel panels have a warm, velvet-like surface texture. These frame irregular openings of simple, mullion-less glass, and the details at these edges seem intentionally fragile, emphasizing the building's tenuous distinctions between inside and out. On the north elevation, a more regimented grid, steel plays a background role, framing large opening of channel glass with aluminum-framed windows within.
Inside, steel is also exploited for its planar and tensile qualities. In particular, a grand staircase structured entirely of plate steel punctuates the central forum space. Made of simple brake-shaped and welded plates, its flights of stairs jump across the space, supported only by steel guardrails and stringers. These structural gymnastics, engineered by Guy Nordenson with local associates SEA, provide an almost encyclopedic demonstration of steel techniques while energizing an already provocative space with a dramatic focus. Interestingly, the 150 cm deep steel plates that form the spanning support for landings also define what have become informal conversation spaces. Harbored by tall steel, these spaces have a surprising intimacy that a more typical stair with only a code-required guardrail would lack.
Throughout, steel is detailed to expose its edges, its thinness, and the raw forms and textures of its production. Connections are left exposed, nothing is mitred or ground smooth, and the steel structure's connections to the floors' precast planking is left open. On top of these planks, polished topping slabs are level with the expressed top flanges of the supporting steelwork. Outside, Holl's more aspirational intentions for thinness and tenacity have been successfully translated into the insulated glass and cold-bridge insulation necessary to survive Iowa's winters, an achievement that McVoy credits in part to a healthy collaborative relationship with local architects HLKB. The result of this consistent approach to exposed detailing is a building that reveals its formal conception and constructive logic in ways that are often intentionally unrefined: 'country simple' detailing, in the local idiom. There are moments where the distinction between plain-spoken and merely plain becomes blurred, but overall these are absorbed into a broad palette of frank, direct materials and details. The result is a building dense with experience and nuance. Taut planes seem constantly to both harbor space and to propel views out into the landscape, and one is constantly aware of edges, lines, and planes, while volumes seem to only rarely cohere. But the overall effect is remarkably harmonious, even placid at moments, in part because of the red-painted steelwork that forms a constant, organizing presence: a clear-mannered counterpoint to the building's enigmatic forms. In its opening months the building has proven popular with faculty and students, who value its qualities of light and comfortable social spaces alongside its more cerebral themes. Most tellingly, perhaps, students have noticed that a damp finger can leave traces in the weathering layer of the skin until the next rain; despite the University\'s (perhaps ill-advised) attempts to erase or clean these, messages, cartoons, and philosophical epigrams have all been lightly traced into the steel. "Rusty Grafetti!" says one, to which another responds "Spelling!" Like the rest of the building, the steel skin invites touch and dialogue, perhaps in ways unforeseen.

Aus der Ausgabe 03-2007