Rael San Fratello Retrospective Centres on a Structure 3D Printed From Soil, Straw and Water
Yerba Buena Center for the Arts (YBCA) in San Francisco presents Prototypes and Provocations, a mid-career survey of Oakland studio Rael San Fratello. Its centrepiece, Sanctuary, was 3D printed on site using only soil, straw and water.
Two Decades of Material Experiments
Rael San Fratello was founded in 2002 by Ronald Rael and Virginia San Fratello. The exhibition, curated by René Morales, opened on 25 September 2026 and runs until 31 January 2027. It traces the studio’s practice from early experiments that merged clothing and construction, through projects addressing the US–Mexico border, to its work in 3D-printed architecture.
On their own website, the partners describe how the studio has become “material scientists, or better, cooks”, developing recipes for 3D printing and using the printed brick as a basic architectural component.
Printing With Earth
Sanctuary is a large cylindrical structure that visitors can explore inside and out. According to YBCA, it was printed on site from earth using robotic technology, with Solyndra rods embedded in its walls. The designers call earth humankind’s oldest building material and present the work as a demonstration of the ecological building techniques they have developed.
The approach builds on earlier work. For Casa Covida (2020), a case-study house in the high desert of Colorado’s San Luis Valley, the studio and its company Emerging Objects printed sun-dried adobe made from sand, silt, clay, water and straw. They used a portable robotic arm that two people can carry and one person can operate from a phone, moving it up after each session of roughly 400 mm of wall height.
Waste Streams as Printing Material
Alongside Sanctuary, a table in the exhibition displays 3D printed objects made from sustainable, recycled, local or waste-stream materials, including salt, chardonnay grape skins, coffee grounds, clay, sawdust and ash from California wildfires.
Similar recipes appeared in the Cabin of 3D Printed Curiosities (2018), a backyard cottage in Oakland. Its roof and gables are clad in around 4,500 3D-printed ceramic Seed Stitch tiles, and its planter tiles combine chardonnay pomace, sawdust, Portland cement and recycled coffee grounds.
The survey also shows Teeter-Totter Wall (2019), bright pink seesaws that were temporarily installed across the US–Mexico border wall. Together, the works show how the studio moves between material research, building and social practice.
Sources: Yerba Buena Center for the Arts / Rael San Fratello, Casa Covida / Rael San Fratello, Cabin of 3D Printed Curiosities
Images: courtesy of Rael San Fratello