BY LUKE AREHART
On a familiar gray morning in downtown Portland last Friday, the AIA/Portland Center For Architecture opened its door for the first of four sessions of its 2013 Design Symposium Skin: Pushing the Envelope. Providing examples from two recent buildings devoted to art and football, Chris Bixby was on hand to present on The Clyfford Still Museum by Allied Works Architecture, while Owen Turnbull, Kelvin Ono, and Brad Iest were there to talk about the University of Oregon’s Hatfield-Dowlin Complex by ZGF Architects.
In architecture, the term building envelope or ‘skin,’ is used to describe the enclosure of interior space by a surface. As such, the skin of a building can often be described as the façade as it is the visible planes that draw distinction from the outside and wrap the various spaces inside. The skin of a building is incredibly dynamic as it is responsible for a large portion of architectural concepts such as structure, usefulness and aesthetics.
The first project of the session to be discussed in terms of the design of its skin is The Clyfford Still Museum located in Denver, Colorado and completed in November 2011. Still was an American artist and one of the first abstract expressionists. His will stipulated that any city that would agree to build a museum for his collection would be granted his art collection to display. The museum itself was to hold nearly everything that Clyfford Still had painted before his passing in 1980.
The site plan for the new museum included the addition of a tree-dotted plaza at the north entry that opened up important views and access to the busy 13th Avenue that bisects the larger complex of museum and public spaces. One of the main design goals on this project was to integrate the landscape of the site and “to create a building that reflected [Clyfford Still’s] philosophies and his feelings about art and life,” Bixby added, in addition to making a sense of weight to the project with a piece of architecture that could be seen as “of the earth.” As the grove of trees in the plaza reach maturity, they will blend and merge with the textured exterior of the museum’s walls and address one of the stated project goals to have the visitor “find themselves in the building and not feel like they were approaching an object, per se.”
As Bixby showed in conceptual models used in the competition, the exterior concrete skin was a product of many episodes of investigation and experimentation. Allied’s architects would try out different mixes and variations in formwork to note the response and form of the mixture after it hardened. They were looking for an aesthetic that would look “sourced from geological patterning with natural looking strong forms that would add to the sense of weight,” Bixby added. The team “had a great deal of assistance from the contractor who was brought on very early in the project, who self-performed concrete. They had their concrete crew on hand whenever we needed them or wanted to talk to them.” The project team continued to do mock-ups and tests at a larger scale with the general contractor that started to develop the spatial implications of cast concrete. One such idea was to “use rock salt, glued to the interior of the formwork,” which would then be washed away to reveal the pattern of the temporary salt molds.
The project team settled on a wood board-form strategy, laying wood up inside the gang form system and pour concrete in to it. By the virtue of the shape of the wood it would stick to the concrete, and as the workers pulled out each board individually, the gaps between the boards would break off in different ways and create the organic pattern. “We were looking for something where this final result was a product of the process of its making,” Bixby explained.
Keeping moisture out was a very important consideration due to the climate in Denver and the value of the artwork inside. Libeskind’s nearby building, for example, had to have its skin disassembled after only six months due to moisture penetration. The other element that needed to be integrated into the wall system was insulation, as the exterior wall was concrete. “All of the exterior perimeter walls are backed with a gallery wall that is furred out with a cavity in between,” Bixby added. “We also have places where an exterior surface wraps into an interior wall to expose the structure and hang art from it, which was important to us from the early concepts.”
One particularly interesting aspect to the concrete fins was the idea that the appearance and pattern might change or adjust over time, or that the textured aggregate would provide a place for moss to grow. But in order to keep the pristine image of the museum, various surface chemicals were used on the exterior to prohibit any growth or graffiti.
In all, the Clyfford Still Museum showcased the ability of a building’s skin to take on a beautiful aesthetic while acting as structure. Even given the long-used and familiar nature poured concrete, there were opportunities within the process to make a truly dynamic façade.
Next up for this session, a panel of designers from ZGF Architects presented their design and process for the newly constructed Hatfield Dowlin Complex, an operations center for the University of Oregon football team. Owen Turnbull, Kelvin Ono, and Brad Iest each discussed the project, which has only been open for about a month.
A key to the Hatfield Dowlin was the articulation of various volumetric boxes arranged amongst each other to express the programmatic uses on the interior. The façade was then used to develop structural variation and differentiation. Since the program of this building had a multitude of uses for all of the various aspects of running the team, the exterior skin had to respond dynamically to encompass each use.
One of the first design moves was to create spaces above the flood plane by making “a podium at the plaza level, which sets the complex up to have an urban context,” Ono explained. “The first programmatic block anchors the practice field and starts to provide a base for the other blocks.” The building’s skin in the project was used to fold in an attempt to blend the exterior plaza and public spaces together with the highly private interior spaces. “You can inhabit the space that the façade enwraps,” he added. “The building is really about the skin as an expression, the skin of the building is what makes it so unique and special.”
To develop the design, the ZGF project team looked to body armor as inspiration, specifically that of a Samurai. They loved the speed, movement and agility that is expressed, as well as the idea that each piece of armor is unique and serves a purpose. Each piece becomes an extension of the Samurai’s skin. It also follows that the armor/pads of the University of Oregon football players served as inspiration as well. The skin on this building strives to match this caliber of stealthy sleekness that has become synonymous with Oregon football.
The ZGF team used standardized dimensions for the modules that would visually slide in and out of a surface plane to develop a porosity of sorts from each volume that never touch each other directly. The building’s skin has a very dimensional aspect to it with the addition of the system of layered glazing. Partially rationalized and party pure aesthetic, the darkened ‘sunglasses’ to the building deliver a sleek look to the façade while providing various gradients of protection to the sun-facing west facade and the view of the practice field facing offices and spaces.
The presenters also delivered stats on metrics that measured the performance of the mostly glass façade. For a couple of configurations the team showed the value of the Solar Heat Gain Coefficient (SHGC) which measures the potential rise in temperature to the interior space from solar radiation and the coefficient for visibility which puts values to sun absorption and glare.
Each of the remaining three sessions for the AIA Portland 2013 design symposium will also focus on a pair of projects completed by prominent local firms.
This Friday, September 20th SERA Architects will be discussing the Edith Green-Wendell Wyatt Federal Building, and members from Opsis Architecture, LLC will present on the Building 7 addition for Portland Community College’s Rock Creek Campus.
The AIA Design Symposium series is moderated by Corey Griffin, who is an Assistant Professor in the School of Architecture at Portland State University, teaching design, structures and building technology courses.
The sessions run from 8:00am-12:00noon at AIA Portland, AIA Portland (403 NW 11th Ave Portland, OR 97209). The cost for individual sessions is $100 for AIA Members and $140 for non-members. Participants are eligible for 16 CEHs/HSWs learning units. For additional information on each session and to register visit: http://aiaportland.org/education/upcoming-classes/2013-design-symposium-skin-pushing-the-envelope As of this posting, sessions are sold out. Please call Liz Rhodes at AIA/Portland (503-223-8757) to be put on a wait list.