Robert L. Thornton, AIA, established RTA on May 1, 2005, with the idea that architecture should be a collaborative process. People—both clients and those who use the buildings—are a key element in architecture, and we believe that buildings should be humane, functional, and responsible. RTA’s principal architect was LEEDs-certified for green building practices before it was fashionable. Before beginning RTA, Rob Thornton was a partner in the firm Erstad Thornton Architects, which he founded with Andy Erstad in 1998.