Unveiled in 1995, the “Light Construction” exhibition celebrated a growing interest in lightweight and translucent architecture. Organized by curator Terence Riley at the Museum of Modern Art, the collection of 30 projects revealed architects’ disposition toward minimizing material substance in buildings. Enabled by technologies such as double-glazed envelopes or media projection screens, “Light Construction” emphasized the aesthetic possibilities of lightness in architecture.
Over the past century, other arguments for lightness have included ecological concerns, such as Buckminster Fuller’s aim for “maximum gain of advantage from minimal energy input” and expanding functional capabilities, as in Frei Otto’s pioneering lightweight structures. Today, a novel building technology called STFE promises to satisfy all three objectives—aesthetic, ecological, and functional—in the pursuit of an architecture of the least substance for the highest impact.
STFE stands for Structural Transparent Fluorinated Envelope, a high-performance architectural textile developed to cover expansive areas with minimal material. Developed by the manufacturer Serge Ferrari Group, STFE-50 (with 50 percent light transmission) is designed for long-span, daylit spaces such as airports, sports arenas, or conservatories. The STFE acronym is a nod to ETFE, or Ethylene Tetrafluoroethylene, a transparent polymer textile used widely in place of glass due to its lightness (approximately 1% of glass). Described by the manufacturer as “the first flexible, long-lasting structural membrane to achieve transparency levels rivaled only by ETFE, glass, or polycarbonate,” STFE enables single-layer coverage of an entire building with a robust, flexible, light-transmitting material.
Despite ETFE’s light weight, its low strength and brittleness make it unsuitable for covering long-span structures. Instead, ETFE is typically applied in the form of individual pneumatic modules. In contrast, STFE enables expansive applications like glass with a material weight closer to ETFE. “STFE was meticulously developed with a non-transparent structural mesh on one side, counterbalanced by a fully transparent side devoid of any structural elements,” explains David Peragallo, Senior Specification Manager North America for Serge Ferrari Group in an interview with the author. “This opened an entirely new avenue for applications and allowed customers solutions that filled the previously existing gap in this market.”
STFE’s secret ingredient is polyarylate, a high-performance thermoplastic polymer used in the automotive and electronics industries These polymers are often used in applications in which a combination of high strength, chemical resistance, and temperature stability are required. Polyarylate meshes are typically lightweight and durable and, in the case of STFE, comprise the structurally reinforced side of the material. Serge Ferrari Group adds an additional PVC coating to protect the individual yarns from the elements, giving the material a life expectancy of 30 or more years. The resulting composite is ten times lighter than glass, and its material strength enables architects and engineers to reduce the number of supporting structures and cables that would be required for a typical glass envelope. In the spirit of “Light Construction,” this structural versatility is accompanied by translucency, and the material’s 50% light transmission reduces glare while providing filtered daylight for building occupants and foliage.
An STFE case study is the 2022 MPavilion. Commissioned by the Naomi Milgrom Foundation and designed by Bangkok-based firm all(zone), the temporary summer venue was constructed as a public shade structure in the Queen Victoria Gardens in Melbourne, Australia. According to Peragallo, “The MPavilion evokes a cloudlike shape floating a few feet above the ground and the temporary structure’s canopy consists of three successive layers—a perfect combination of flexible composite materials.”
A 250 m2 STFE-50 membrane incorporated for rain protection and daylight transmission serves as the middle roof layer. The architects employed fishing nets as the uppermost layer for additional light filtering. The bottom layer is composed of 1400 m2 of Serge Ferrari Group’s Soltis 86 mesh screen, made using the manufacturer’s Précontraint technology, in which a coating is applied under bi-axial tension to extend the material’s life. “Assembled into a waffle-like composition, the fabric filters the sunlight, creating a play of brightness and nuance to delight visitors,” explains Peragallo.
Potential STFE applications vary widely. Initially intended for large buildings like stadiums, train stations, and airports, STFE is also finding its way into small, tent-like structures such as MPavilion. The relatively low ecological footprint of the material, due to its fulfillment of facade functionality with minimal substance, also has economic advantages. “Building material costs have continued to skyrocket throughout North America,” says Peragallo. “With the cost of steel and other support structures rising, STFE offers a cost-saving building product solution for commercial projects.”
Based on its compelling properties, STFE has the potential to facilitate the broad attainment of light architecture—and magnify the aspirations of MoMA’s 1995 show. “In this architecture of ‘lightness,’” Riley wrote in Light Construction, “buildings become intangible, structures shed their weight, and facades become unstable, dissolving into an often luminous evanescence.”
The views and conclusions from this author are not necessarily those of ARCHITECT magazine.
Read more:The latest from columnist Blaine Brownell, FAIA, includes an interview with Pritzker prize-winning architect Riken Yamamoto, a review of 3D-Printed Nanocellulose Materials, a roundup on sustainable manufacturers in Egypt, a review of the Grand Egyptian Museum, a look into Cairo's informal settlements, a profile on textile designer and weaver Suzanne Tick, and he also looks at emerging carbon capture and storage technologies, the blue economy, and AI's impact on supply chain management.
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