The role of the architect has always been somewhat problematic in one respect: While the designer is considered the author of the building, there is often a gap between the design concept and what winds up rendered for posterity in bricks and mortar. The goals of the profession can be abstract, whereas the end and sole purpose of its efforts have always been grounded in the physical—what can be built, and for how much money. The result is that, in spite of high aspirations, the idea of the building sometimes surpasses the end product, much like Plato’s ideal chair.
Although architects may go through endless drafts of shop drawings and spend hours on site, it’s not unusual for a building to reach completion with some misgivings from the design team. You hear things like, “In early sketches we had one sinuous curve, but it turns out they could only fabricate the panels in flat sections, so we wound up with this segmented condition.”
Control is what it comes down to. How can architects assert more control over the physical outcomes of their designs? One method that is now gaining momentum is digital design and fabrication. Today’s 3D computer modeling programs, such as Rhino and CATIA, have evolved into an integrated system in which designers can embed more and more information into their geometric representations, then translate these directly to production processes. This happens thanks to CNC (computer numerical controlled) machines, which use the same digital information laid down by architects to fabricate physical objects. The process moves the designer one step closer to production—it puts the architect in the machine.
Of course, even with more power to wield over the outcomes of their designs, architects still have to deal with project-specific conundrums and work with materials that have their own peculiarities. The three case studies that follow show how designers can adapt the digital design-and-fabrication process to a unique set of circumstances and a unique set of materials to create meaningful forms.
Gail Peter Borden
Materials & Applications is a nonprofit that produces two architectural installations each year on a smallish infill lot in the Silverlake neighborhood of Los Angeles. The exhibitions are free to the public; the goal is to create a test bed for new concepts in building. The most recent installation was called “Light Frames.” It featured two separate structures, made from different materials, that sat adjacent to one another and nearly filled the little lot. The first structure is a skeletal metal dome made from bolted 1-inch-diameter galvanized-metal electrical conduit. It straddles the entrance to the lot and directs visitors toward the second structure, a chapel-like volume of inflated translucent and white vinyl, which is pierced through at intervals by apertures that let light inside while framing views to the exterior.
The project’s designer is Gail Peter Borden, AIA, a professor at the University of Southern California who also runs his own firm, Borden Partnership. “This project was a response to L.A. materials,” Borden says. “The conduit is a basic off-the-shelf material that references Gehry and chain-link fencing, while the vinyl carries the idea of plastics and the new materiality of Southern California. The two pieces sit in conversation with each other. … They both employ primal architectural forms.”
The budget was also primal, so to speak: less than $3,000 for each structure. With that kind of funding, Borden couldn’t afford to shop his designs around to digital fabricators, but the digital design process did, in the end, transfer directly to the construction process. Rather than turn to a high-tech machine shop, Borden relied on a hoard of student volunteers. He also had help from a heavy hitter in the industry: Buro Happold helped with the structural form-finding for the metal element and ensured its safety as a jungle gym, since Materials & Applications sits just a few doors down from Spaceland, one of L.A.’s premier rock-and-roll venues. (“People sometimes get drunk and then come down and interact with the installations,” Borden says.)
The metal dome was modeled in Rhino, and the drawings bounced back and forth with Buro Happold as they worked out the stresses and effects of bolt connections on the lengths of the conduit. That same model was in the shop for reference while the students prefabricated the structure in five sections, and it was there on site when the sections were bolted together, acting as a reference and guiding the erection process.
The vinyl structure was modeled in CATIA, a parametric modeling program designed for the aircraft industry. Unlike Rhino, which is a simple 3D model that establishes points in space, CATIA allows the designer to imbed parts of a model with information that is governed by rules, or parameters. The parameters allow the program to calculate and make global changes throughout a model when the designer makes a local change. In this case, the 3D model was broken down into a series of shapes that could be cut from sheets of vinyl. CATIA turned each 3D piece into a flat piece. Once the entire structure was designed, all of those pieces were exported to RhinoNest, an optimization plug-in to Rhino that allowed the team to save on material. These optimized shapes were then printed as templates that the student laborers used to hand-cut the vinyl with knives. Borden considered using CNC laser-cutting for this part of the process, but it proved too expensive: Plus, the lasers would have singed the edges of the material, making for an unseemly edge condition.
The students assembled each of the vinyl pieces with heat and chemical welds, forming a unitary inflatable structure, much like a bouncy castle. Then the entire assembly was draped over a very minimal conduit structure—just strong enough to hold up the fabric. Once this was in place, two blowers were installed to inflate the pneumatic chapel. The blowers are set on motion sensors, meaning that the structure will inflate only when there’s someone there to appreciate it.
Whistler Olympic Village Bus Shelters
Urban Movement Design and Associated Fabrication
Robyne Kassen, Assoc. AIA, and Sarah Gluck of New York City–based Urban Movement Design work in an area where movement, health, and architecture intersect. Trained as architects, the duo also specializes in yogic therapy and special-needs design. The first project that they worked on together, in 2005, was designing furnishings for the wheelchair-bound.
Their next project was a series of bus shelters, benches, and bike racks for the 2010 Whistler Olympic Village. Kassen and Gluck sought the project out themselves. Knowing that the Olympics would be held in Whistler and Vancouver, British Columbia, Canada, they guessed that the Paralympics would be held there as well. The duo flew to British Columbia and pitched the local director of planning, who it just so happened had studied kinesiology—the science of human movement. He was receptive to Kassen and Gluck’s doctrine of design promoting health and sent them back to New York to flesh out their proposal.
While Urban Movement’s Olympics amenities provide all the normal functions, they also take into account ergonomics, encourage deep relaxation, and provide an arena for users to stretch and strengthen. These factors are most evident in the bench component, which goes beyond the idea of a slab on which to rest one’s behind. Rather, the surface morphs throughout its length to provide a variety of degrees of human repose, from a fully reclined Lay-Z-Boy–type position to an ideal upright position. “Points of contact are so important,” Gluck says. “If you lie on a flat surface, your body will tend to conform to that surface, but we are not flat.
“The digital process allows us to make curved surfaces with great accuracy that will support the body in a healthful way, allowing the muscles to fall into alignment and ensuring that when we do move, we do so from a place of comfort, not stress.”
Gluck and Kassen chose solid surface for their benches because it is soft and pleasant to touch, nonporous and hygienic, robust enough to withstand extreme weather, and easy to recondition after being besmirched with graffiti. The solid surface can also be thermoformed, making it perfect for creating the smooth and delicate curves necessary to provide the full support called for in the design. While solid surface makes up the bench surface, the frame is composed of ribs of marine-grade plywood. The designers sketched the benches in Rhino and sent these files to Associated Fabrication, a shop in Brooklyn, N.Y., outfitted with CNC systems.
The folks at Associated refined the Rhino models and plugged them into their machines. It was simple enough to cut the profiles of the plywood ribs on a CNC router, but thermoforming the solid surface proved to be more of a challenge. While the material is plastic, it does have restraints in terms of how tight a radius it can be used to form—it starts to come apart as it approaches a 90-degree angle—and Urban Movement’s design called for some pretty tight radii. To solve this problem, Associated came up with a system of cutting groves into the surface of the material that allowed them to get more drastic curves without compromising the material’s structure. They made molds of the benches out of MDF—also cut on a CNC router—and then heated the solid-surface sheets to 350 F, rendering them as pliable as rubber. “To heat [them], we use a platen oven,” says Jeffery Taras of Associated Fabrication. “It’s a big drawer, and the top pneumatically lowers on to the … [material], so that the material is in constant contact with uniformly heated aluminum platens.” The heated material was then drawn down over the molds on a membrane-press vacuum table and allowed to cool.
The digital-fabrication process made it easy and affordable to create one-to-one mock-ups during design, a key to getting the benches right. “It was an ongoing process,” Gluck says. “Associated would do a mock-up, and then we would go in and test them with our bodies.”
The 2008 show at MoMA “Home Delivery: Fabricating the Modern Dwelling” focused on the history of prefabrication in home building. It began with the premise that the practice had been around for a long time—back to balloon framing, at least—and also looked at what new forms of prefabrication might be available to designers and manufacturers eager to leverage technology in home building. In this direction, the museum commissioned New York City architecture firm Marble Fairbanks to design a future wall fragment. “We wound up with a screen wall that would use flap stock metal panels, completely cut in the factory to minimize labor on site, and capable of flat packing to minimize shipping costs,” says Robert Booth, a project designer at Marble Fairbanks. “We also had a goal of giving it some visual effects that would be strong and come across to museumgoers.”
Before coming to that point, however, the designers began their conceptualization by considering a very common contemporary home building material: the metal stud. They were interested in the intelligence embedded in that seemingly mundane object, the way it has quickly changed how homes are designed and built. Specifically, they were impressed by the product’s knockouts, which allow the passage of conduit and piping, making the job easier for other trades on site.
Marble Fairbanks wanted to imbed a similar intelligence into its wall, but instead it focused on openness. This openness was created through the mechanism of the wall’s connections, which are integral to each surface. It works like this: The screen wall is made up of two 16-gauge stainless steel panels. Tabs are laser-cut across the surface of the panels. The tabs fold 45 degrees toward the other panel. The other panel features a sister tab that folds to meet the first. These two come together to form the connection (no other connectors are needed, and the wall system can be assembled entirely by hand). They also form apertures through the wall, creating the screen effect.
The architects modeled the wall primarily in Digital Project, a 3D parametric modeling program developed by Gehry Technologies that is based on CATIA. “The whole project is two levels of scripting, one level that controls the tab, one that aggregates the connection,” Booth says. “One form allowed us to create the connection, the other to manipulate the connections.” The program also allowed the designers to play with the connections to create different looks for the screen wall. “There’s a lot of flexibility in how the connections can be arranged in the surface,” Booth continues. The tab shape and pattern they eventually decided on were chosen for aesthetic reasons; others could have worked equally well.
Digital Project outputs Rhino files, which Marble Fairbanks transferred to AutoCAD files, representing the flat form that would ship from the factory. These drawings were sent to Maloya on Long Island, N.Y., which laser-cut the stainless steel sheets and then had then trucked to MoMA, where Booth and his team performed all the tab bending. “We put in a dashed line allowing the tabs to bend easily and be straight,” he says. “All you had to do was push, and it knew where to bend.”