Soaking up the sunMay 1st, 2016 / By: mlenger / Category: Fabric Structures, Markets
Solar-powered Techstyle Haus demonstrates the aesthetic and functional benefits of state-of-the-art fabric architecture.
When the 2014 Solar Decathlon Europe issued a call for attractive, energy-efficient homes powered by the sun, one team of design students tapped the potential of fabric architecture.
The competition submission, known as Techstyle Haus, brought together 50 students from Rhode Island School of Design (RISD), Brown University and the University of Applied Sciences in Erfurt, Germany, to demonstrate how textiles and high-performance membranes can substitute for traditional masonry and wood construction.
“Membranes can be a technically superior alternative to solid sheathing because of how they interact with the environment,” says Jonathan Knowles, associate professor of architecture at RISD and one of three Techstyle Haus project faculty advisors. “Their permeability can vary with changes in humidity and temperature to help keep out unwanted vapor while also allowing the skin to breathe.” As such, the membranes are able to passively control humidity and latent heat—a feature that helped meet the Solar Decathlon’s stringent passive-house energy requirements.
The team designed a curved exterior shell made with Saint-Gobain’s Sheerfill® II architectural membrane, a material typically reserved for domed sports stadiums and airplane hangars. It was the first time the membrane had been used in residential construction, according to RISD. Steel structural ribs supported the textile in place of traditional framing elements such as wood studs with plywood sheathing or direct application of the material to concrete. Atop the structure, a solar array made from laminated photovoltaic cells was sewn into the skin.
In just 18 months, the students designed, prototyped and built a system of strapping and cleats to suspend the home’s insulation and allow the finished fabric to follow the complex double curvature of the exterior shell while minimizing contact between the steel frame and the interior.
“This system of attachment allowed the wall and ceiling to perform as a continuous super-insulated enclosure,” Knowles explains. “Our students created a completely thermal bridge-free wall.”
Learning by doing
Although the young designers had mastered the exterior and insulation system, they struggled with finishing the house’s 825-sq.-ft. interior. With less than six weeks left before needing to ship the project to Versailles, France, for installation, the team approached Transformit Inc. in Gorham, Maine, for its expertise in fabric structures.
“After they contacted me for the first time, it took me a week and a half to figure out how I was going to help them,” says Cindy Thompson, Transformit founder and president.
Thompson needed to find the best way to cover up the obtrusive bright orange straps holding the insulation in place, while complementing the sculptural flow of the exterior. The interior also had to be easily transported to and reassembled at its destination.
The students had already chosen an upholstery fabric, but Thompson canceled the agreement because the fabric “had a non-stretch woven structure that would have made patterning a wrinkle-free installation impossible in the limited time available,” she says. Another concern was that the fabric, measuring only 60 inches wide, would have added too much weight to the house.
Instead, Thompson recommended a dual-skin construction. The first layer was a light-blocking fabric called Molton Colour to conceal the insulation. Like the upholstery fabric, the light-blocking fabric’s rigidity made it difficult to create a pattern in a complex shape without any wrinkles.
Creating a wrinkle-free look necessitated the second skin. Thompson selected white PolyStretch P8 CS, which she describes as “a very nice stretch material that allows you to make a curve.” Both fabrics were sourced from ShowTex in Belgium, because they met the French fire codes required for the installation’s two-week stint in Versailles.
The two fabric layers are held apart on a custom frame of aluminum tubes that attached to the house’s steel frame. The clever use of zippers hid the framing.
To customize the interior finished fabric, RISD students knitted two wool panels inspired by the monochromatic French toile but didn’t know how to best mount them to the interior walls without visible fasteners. Transformit staff showed the students how to create another two-fabric construction. The students tensioned each knitted panel around an internal frame with stretch fabric on the backside, then mounted them closely to the house’s interior walls using hidden standoffs.
Zipping the wool to the stretch fabric was difficult “because it was created on a knitting machine and you have different kinds of stretch going on,” says Thompson.
The finished panels added an artistic flair to the interior. “The knitted fabric allows for custom patterns and provides an innovative solution for lining the doubly curved interior shape,” Knowles says. “In sharp contrast to traditional masonry or plaster walls, the material quality of the fabric dynamically reflects light throughout the space.”
In fact, integrating art in the architecture was a priority for the student designers and for Transformit. “There are all of these technical things you have to do, but you have to keep the feeling and essence of the art,” Thompson says. “Otherwise, [the project] falls apart.”
Finishing the Techstyle Haus interior took about a month. Students traveled from Rhode Island to Transformit’s Maine studio to work directly with the company’s head designer and chief stitcher on patterning and cutting. With sewing machine in hand to make on-the-spot edits, Transformit staff traveled to RISD to help with the dry-run installation and train the Versailles installation team. Four days later, the students dismantled the house and shipped it to France for the Solar Decathlon.
Techstyle Haus earned third place in the category of “Comfort Conditions” and finished 14th overall in the competition. The fully functioning net-zero-energy prototype currently provides housing at Domaine de Boisbuchet, which hosts art and design workshops in Lessac, France. The project also won a 2015 Outstanding Achievement Award in IFAI’s International Achievement Awards competition.
Educating future architects
Transformit’s sponsorship of Techstyle Haus garnered many lessons for the design students. “The Transformit team helped us develop a smart solution to a demanding problem in a very short amount of time,” Knowles says. “They also were natural teachers who spent patient hours with our students showing how to quickly install the final assembly.”
Ultimately, the hands-on approach gave the young designers real-world experience. “Rarely do students have the opportunity to work alongside industry to see their creative work so quickly and beautifully realized,” Knowles adds.
Transformit staff also benefited from the collaboration, seeing it as a chance to train the next generation of fabric architects. “Of all of the art and architectural schools I know, not too many of them even talk about fabric,” Thompson says.
That’s why she makes education a priority. “I give many lunch-and-learns to architects, and it is a huge educational process,” Thompson says. “They’re always amazed because they didn’t know fabric could do all of this.”
Holly O’Dell is a freelance writer and editor based in Joshua Tree, Calif.