Fabrication has entered the forest. In August, Bryan Allen, Assoc. AIA, and Stephanie Smith of Oakland, Calif.–based design firm Smith|Allen completed what was then one of the world’s largest installations of 3D-printed micro-architecture. Conceptualized during a four-week residency with arts incubator Project 387, Echoviren is a sculptural, 8-foot-tall, 8-foot-wide pavilion tucked into the center of a 150-acre redwood forest in Gualala, Calif.
An oculus directs the visitor’s gaze upward into the tree canopy, highlighting the dizzying verticality, a striking contrast to the lateral motion of hiking through the trees to reach the pavilion.
Arriving at the site, Smith and Allen were struck by the scale, simplicity, and homogeneity of the redwood forest. They wanted to insert a small hermitage where visitors could sit and rest. “We found our eyes being constantly drawn up by the lines of the trees,” Allen recalls. “We conceived it as a place where the normal, horizontally transverse experience of the forest can be challenged by highlighting the verticality of the forest space that we often overlook.”
This particular plot of land had been logged three times—in the late 1880s, 1930s, and 1960s and ’70s—and grown back completely each time. The couple was interested in highlighting the site’s history as mediated by man, technology, and nature, says Smith: “Using technology that we know will disintegrate, we created a starkly disjointed space within the forest to make this history visible—and encourage the viewer to sit and engage with it.”
Allen and Smith enlisted the software programs Rhino and Grasshopper to generate the structure's dimensions—which echo the grove’s textures and forms—and to define the connection details for each printed component. The translucent blocks that comprise the $6,000 pavilion are textured with the exposed print lines and a surface synthesized from that of the sequoia’s cellular structure and its bark. For 60 straight days, continuing up to the very end of construction, seven Type A Machines Series 1 printers churned out 500 unique, branch-shaped blocks from 140 pounds of sugarcane-based polylactic acid. Limited in size by the printers’ output capacity, the blocks' dimensions range from 6 by 9 by 0.5 inches to 8 by 9 by 6 inches. The print times for each component varied, depending on its complexity and required strength. The blocks at the base, for example, took about 14 hours each, while blocks at the oculus required only four.
The branching geometry of the blocks emulates the forest itself. Over a period of three weeks, the designers took photos of existing textures in the grove and translated them into drawings that were elaborated parametrically in the computer to define the wall's apertures. Rhino and Grasshopper helped generate the overall form of the structure, wrap the texture to it, define the connection detail, and insert this into each unit. Allen says that the blocks framing the roughly 63-inch-tall-by-20-inch-wide irregular pavilion opening yielded some unusual pieces because they had to be self-supporting.
Each piece had its own detailed design file—an STL (standard tessellation language) file, which directs how each block will be sliced into areas for printing, and a G-Code file, used for CNC machining—making file management a big challenge. Smith and Allen numbered the blocks based on each one's location in the structure to aid construction. Assembly took the pair four days, starting with a foundation dug 7 inches below grade.
“All of the [file] names had to be right to make sure it went together,” Allen says. “There is also no queuing system for the printed files so we had to keep track of what printer was printing which file. …This whole process is very piecemeal now, but as printers get better the software will, too.”
The project title was inspired by the California coast redwood’s scientific name, Sequoia sempervirens, which translates as “always alive” or “always green.” For the next half-century, Echoviren will biodegrade, the colonizer slowly colonized by its host. Mosses, fungi, birds, and spiders began taking up residence even as the designers assembled Echoviren on site.
“We wanted the piece to be a place of contemplation within the landscape and about the landscape—a conceptual and physical echo of its surroundings,” Smith says. In the shadow of the giants around it, Echoviren glows like a lantern at night, thanks to LEDs rooted into its earthen floor. With permission from Project 387, it is open 24 hours a day to people and nature, alike.