He has been teaching at RISD since 2001 and was project director for RISD's 2005 Solar Decathlon entry. He has initiated a pilot project with the Department of Engineering at Brown University to conduct research into new forms of thermal electric systems. Knowles has taught at the Parsons School of Design, Cornell University, and Columbia University. He is also a practicing architect and passive house consultant in New York City, where he is a partner at Briggs Knowles Studio. The work of the firm has been published in several venues, including the New York Times and Dwell magazine. He is currently overseeing the design and construction of two net-zero homes in New England. His degrees, a Bachelor of Architecture and Bachelor of Fine Arts, are from RISD.