Architects update pre-Columbian building method with modern tools and materials.Matter Design's latest installation, Round Room (on display at MIT's Keller Gallery last fall) was born of a "marriage" between two of the firm's ongoing interests, explained co-founder Brandon Clifford. First, Clifford and partner Wes McGee had long hoped to work with Autoclaved Aerated Concrete (AAC). Clifford, moreover, had been impressed during a trip to Cuzco by the Incan wedge method of masonry construction, in which precisely-carved stones are aligned on their front face, then backfilled with mortar. "This seemed like a tremendously rational way of building," he said. "Ever since then we had been wanting to do a project that translates that process into digital design." With Round Room, designed and fabricated in cooperation with Quarra Stone, Matter Design did just that. Though inspired by pre-Columbian building practices, the installation firmly situates the wedge method in the digital age. Clifford and McGee began by building a rough prototype, a six-component section resembling a half-dome. "We knew that we were going to build something that was round," said Clifford. "Not a sphere, but something that has slow changes in geometry." By focusing on curved spaces, the designers were already pushing the limits of the wedge method, historically limited to two-dimensional applications. With information gleaned from their prototyping session—including the general dimensions of individual units—they worked through a series of models in Grasshopper and Kangaroo, leaning on calculations developed for an earlier project, La Voûte de LeFevre. Clifford and McGee also visited Quarra Stone's Wisconsin facility. The trip "allowed us to get a feeling for where they were going to have problems with the geometry, and make changes," said McGee. "We were able to step in as consultant with respect to applying their tools." Using a water-fed robotic arm, Quarra Stone cut the AAC components—no simple feat. "One critical translation from the Incan technique was the fact that the front edge aligns, but the backwards taper allows for mortar to be packed in," explained McGee. "[The blocks] are machined on five sides." Round Room's components were then shipped to Cambridge and assembled on site by a team of students, including Myung Duk Chung, Sixto Cordero, Patrick Evan Little, Chris Martin, Dave Miranowski, David Moses, Alexis Sablone, and Luisel Mayas. (Austin Smith also assisted throughout the project; Simpson Gumpertz & Heger acted as structural consultants.) The installation team placed the blocks, used scrapers to remove any excess AAC from the front (interior) edge, then piped plaster into the wedge-shaped gap on the back (exterior) side. "Though it was a digital fabrication process, the assembly was quite a craft," observed Clifford. The collaboration with Quarra Stone was a first for Matter Design, which had both designed and built all of its earlier projects. "It was beneficial for us to understand the nuances of what they had to deal with on a daily basis," said Clifford. In fact, the relationship was so successful that Clifford and McGee are continuing it, with a fellowship that will send two researchers to the Wisconsin fabricators. "It's an area we're going to continue working in pretty heavily," said McGee. "It's an opportunity to interrogate this information exchange between designers and fabricators at a higher level."