In 1945, shortly after the founding of TAC, he and his wife Sarah P. Harkness joined forces with another architectural couple Norman and Jean Fletcher, also founders of TAC, to submit entries for the Smith College Dormitories competition hosted by Progressive Architecture magazine.

One of the earliest projects for TAC was the creation of the Six Moon Hill neighborhood in Lexington, Massachusetts which featured many innovations in architecture, landscape planning and community development.

The house he shared with Sarah P. Harkness and their growing family included radiant heat in the floor, skylights that were a reuse of the technology for creating bomber turrets, an open plan in which the kitchen was directly connected to living areas and large expanses of glass.

Wayland High School received considerable attention for its "campus" style and new methods of instruction.

Harkness became Harvard wrestling's first NCAA national champion on March 26, 1938 when he defeated Oklahoma's Marshall Word for the 175 lbs.