Out of the Computer

Virginia San Fratello tries to convert her Next Generation® prize-winning proposal for a Hydro Wall from digital rendering to material prototype.

In the courtyard behind Clemson University’s architecture building, students from Virginia San Fratello’s design studio are serving bananas Foster, po’ boys, and muffulettas for lunch out of digitally designed dishes before their midterm reviews. Part of a project to develop a food museum on a New Orleans wharf through analysis of the site and the material properties of local cuisine, the picnic is typical of the combination of playfulness and challenging design scenarios that San Fratello brings to her students in the small college town of Clemson, South Carolina, about 140 miles southwest of Charlotte. It’s the same spirit of experimentation that inspired San Fratello’s Hydro Wall, winner of this year’s Metropolis-sponsored Next Generation® ideas competition. But the biggest challenge will be getting the digital image rendered in the 3-D modeling program Form•Z “out of the computer,” as she says, referring to the process of building a prototype.

The Hydro Wall is an ingeniously conceived building component that collects rainwater from the roof and stores it in a rubber “bladder” inside the wall to serve as a thermal mass. Intended for hot climates with sharp daily swings in temperature, the wall would reduce air-conditioning costs and energy consumption by preventing the sun’s heat from radiating through exterior walls during the day. The water—one of nature’s best thermo conductors—would store the excess heat inside the wall, and a heat-transfer system could be installed to blow the warm air into the interior at night when temperatures drop. The water could also be used to irrigate plants growing from pockets embedded in the wall’s surface. “The thing that made it interesting was that it generated the design with an eye to both sustainability and experimental form-making,” says Jeffrey Inaba, director of SCI-Arc’s postgraduate program and a member of the Next Generation® competition jury. “As a larger direction for design, it was unique and significant.”

“Last year we went to Yemen, where they don’t use mechanical and electrical systems so much,” San Fratello says, citing one of her inspirations for the project. “They actually use the architecture to move the water through the walls and into the buildings. I was thinking about the difference between architecture that has the systems built into it versus the way we build now, which is thin and layered with engineering systems applied on top. But can these things come back into the architecture?”

It’s the sort of question that San Fratello has been putting to students in her class on materials and methods for the past year, asking them to choose a material that contains an industrial by-product, research its properties and characteristics, and then develop an inventive proposal for its reuse. “In a lot of the buildings that are being constructed, architects are just specifying traditional construction assemblies and buying them—not really inventing or designing them,” she says. “I think it has to do with the expediency with which we build, and time and budget constraints. But designing building components is part of a long tradition of the architect being a kind of master builder in a way that we no longer are. A lot of times we’re just specifiers and shoppers.”

Isaiah Dunlap, a student who collaborated with San Fratello on the Hydro Wall and helped research possible applications, also developed a proposal during the fall semester for a concrete wall system that would function as a cistern to collect rainwater for reuse. San Fratello ended up using his model in her Next Generation® proposal to show how curves in the wall could be used to pool and capture water. “I was researching a list of things you could use the water for,” Dunlap says, “such as irrigation for plant systems, a way to heat and cool the building, or for the plumbing facilities—any type of gray-water application.”

The Hydro Wall system integrates concepts of critical regionalism—the idea that contemporary architecture should be compatible with local climates—with “generative” techniques that use computer programming and digital modeling to mimic natural processes. San Fratello and her husband, Ronald Rael—also a professor at Clemson and her studio partner—both studied at Columbia University in the late 1990s and were influenced by a group there including Evan Douglis, Laurie Hawkinson, and Sulan Kolatan that was developing the concept of generative architecture (highly fashionable at the moment in certain avant-garde circles).

In their joint practice San Fratello and Rael recently began construction of a recreation center in Anderson, South Carolina, composed entirely of a steel frame and exterior walls made up of foliage, and designed an unbuilt house in Marfa, Texas, with water flowing through its building components. “The idea of water moving through the building is an idea that’s been used for thousands of years,” San Fratello says, referring to ancient forms such as Turkish mosques that didn’t have independent plumbing systems. “But I’m trying to figure out how to get it out of the computer, and that’s where those old ideas and new technology start to combine. I think it would be made as a formwork milled from digital files, and then thermal plastic would be applied to that so it would be constructed using high-tech fabrication techniques.”

As in many of today’s most innovative offices, the clash of traditional methods and new technology is where the input of engineers becomes essential. The day after the students’ midterm reviews, Brady Godbey, a mechanical engineering grad student at Clemson, meets San Fratello in her studio to talk about the properties of various plastics and composites, and different techniques for fabrication. According to Godbey, the problem with polypropylene—the cheapest and most common form of plastic—is that it will degrade and eventually crack when exposed to intense ultraviolet radiation, but a sturdier polycarbonate material is much more difficult to shape and can easily be scratched. Both types of plastic could be hard to form into pockets to hold plants because sharp curves would reduce the wall’s thickness in those areas, compromising its strength. “Plastic is going to limit how creative you can be with the design,” he says. “There are going to be stresses that you can’t know about until you build it, look at it, and say, ‘Oh god, what are these cracks doing here?’” He suggests fiberglass, which can support sharp outcroppings but doesn’t have as nice a finish.

San Fratello is just beginning the process of moving the Hydro Wall from digital model to material prototype, and the qualities of the material she finally chooses will have a big impact on the final design. For example, some plastics are manufactured only in 4-by-8-foot sheets, and ideally she is hoping to produce it in 20-by-4-foot sections that can be assembled in the same way as tilt-up concrete panels, with each interval corresponding to a structural steel beam. But despite the difficulty of realizing the project in its current form, Inaba is still not entirely satisfied with the renderings. “It seems like she could push the logic of form-making in a more bizarre, aesthetically arresting way,” he says. “Right now there’s this transparency of what the thing is supposedly doing and its form. The design could be really enriched by there not being such a close correspondence between the wall and the bladder.”

It will be a daunting task, but San Fratello has the advantage of being on the campus of one of the country’s top-rated architecture schools, equipped with a wide variety of rapid prototyping tools—from CNC mills and laser cutters to 3-D printers—that will help push the process forward. “It is good to think about all these things because it really affects the form,” San Fratello says at the end of her meeting with the engineer. “I can make anything on the computer, but when you start talking about how to get it out, that’s inevitably the challenge.”

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