Correspondence relating to Nobbs' participation in several professional organizations, specifically the Art Association of Montreal (1916-1933), the Royal Institute of British Architects (1927-1929), the Royal Canadian Academy of Arts (1928-1939), the Royal Society of Arts (1938-1940) and the Royal Architectural Institute of Canada (1955).

Reports, notes and correspondence stemming from Nobbs's involvement in the Montreal Committee on Housing and Slum Clearance.

Correspondence relating to Nobbs' activities as a professor of architecture at McGill University (1904-1940) and details of his subsequent pension arrangements, as well as the honourary Doctor of Letters awarded him by McGill in 1957. Included are student design problems assigned by Nobbs during his years as Professor of Design at the School of Architecture (1928-1940).

Series consists of manuscripts, typescripts, and correspondence regarding various personal, non-architectural projects undertaken by Nobbs, in particular the design of his deflected northern lighting system for the National Research Council.