Graeme was the founding principal of G. F. Duffus & Company Ltd., which joined forces with DSRA in early 2016. Since 1971, he has worked a wide variety of architectural projects with a special emphasis on building conservation. Graeme has been responsible for projects in the fields of housing, planning, commercial and institutional buildings, both in the public and private sector.

Graeme has prepared conservation plans for numerous heritage buildings and undertaken over 300 projects with varying degrees of repair up to full restoration. Major heritage projects include the preparation of plans for the restoration of the exterior fabric of Halifax City Hall, Province House, Government House and the Provincial Court House on Spring Garden Road. In 2002, Graeme was engaged by the City of Moncton to document, interpret and relocate the Treitz Haus (c. 1767), the oldest building in the city.

Many local institutional projects are among Graeme's project portfolio, including several masonry projects at Dalhousie University, a maintenance assessment on all buildings at the University of King's College, a full condition assessment of NSCAD’s downtown campus, and restoration and conservation work at St. Mary's University.

As a long-time member of the Association for Preservation Technology International (APTI) & the Canadian Association of Heritage Professionals (CAHP), Graeme has lectured and facilitated various seminars in the field of building conservation. He has also authored to several publications relating to Nova Scotia heritage buildings and architectural history.

An active community volunteer over the years, Graeme served as a member of Halifax's Heritage Advisory Committee (1990-1994). He is on the the Sacred Heart School Facilities Committee and presently serves on the board of the Fort Sackville Foundation.