He was particularly proud of his work on the new building of the Scots Kirk in Paris, opened in 2002 and which incorporated elegant design such as a Pictish cross by Jacqueline Stieger which is visible from the street.
He was also awarded the great distinction of a silver medal by the Academie d’Architecture in Paris in 2003 and he helped to organise a bicentennial exhibition in Paris on the work of the great French architect Louis Visconti.
Mr MacCallum was an internationally recognised expert on the work of Visconti and he wrote a paper about the design symbolism of the tomb of Napoleon Bonaparte, hewed from green granite and red quartz, which stands at Les Invalides.
As well as leaving behind a visible mark on his beloved Paris, Mr MacCallum will be remembered in Glasgow as a kind but persistently questioning teacher, during his time as head of the Mackintosh School of Architecture, part of Glasgow School of Art.
Mr MacCallum is seen as having brought his own erudition and academic rigour to the hands-on building tradition of the Mackintosh School of Architecture and increasing the extent of its investigations and enquiry.
He was head of the school for six years from 1994, taking over from his friend and colleague Professor Andy MacMillan.
The pair had been friends from the 1960s, both having married and had children about the same time and following a similar career path. The two families remained friends throughout.
It was in 1960s Glasgow that Mr MacCallum met the young French student of literature who became Andree MacCallum. The couple had two daughters, Sophie and Joelle, one of them coincidentally marrying a direct descendant of Louis Visconti.
The family travelled a lot and lived in many places as well as going back and forward to France, trips which helped Mr MacCallum to improve his grasp of the French language which was excellent.
Mr MacCallum was a also a keen sketcher and a skilled watercolourist who was generally seen by his family with a pencil or a paintbrush in his hand. As well as drawing, he enjoyed gardening.
He had a dry, Scots sense of humour which his friends and family very much enjoyed and despite the fact he spent the last years of his life in Oxford never lost his sense of being very much a Scot. A bon viveur who enjoyed good food and wine, he was also a doting grandfather to four grandsons and one granddaughter.
Mr MacCallum was educated at Hutchesons’ Grammar School in Glasgow and then the Mackintosh School of Architecture before a stint at the Massachusetts Institute of Technology.
He began his career at the Glasgow modernist firm by working for 10 years from 1957 to 1967 at Gillespie Kidd & Coia which is associated with many striking buildings of the late-1950s and 1960s, many of the most iconic built for the Roman Catholic Church.
He then opened his own architectural firm in Oxford before being recruited as one of a “flying circus” of architects who flew in and out of Dublin in the early-1970s to teach at a revitalised school of architecture in University College, Dublin, after a “revolution” by the students who wanted a more modern approach.
For a decade from 1985 to 1994, he then became professor of architectural design at the University of Wales in Cardiff, before returning to Glasgow to take up the post as head of school.
There architect Grace Choi remembers with gratitude his input into her Masters degree for which she won a prize. She said: “He had a very gentle manner and he was very respectful and courteous but he was also very persistent and he would force questions out of me that I never had in my mind at the beginning of the session.”
After retiring from full time teaching, Mr MacCallum and his family returned to Oxford where he continued to lead a full and busy life, working in collaboration with the Franco British Union of Architects to run a scholarship programme which offered opportunities to young French and British architects to spend a year abroad.
Teaching was and remained a huge part of his life right up until his death, and many former students have written to express their sorrow at his passing.
Mr MacCallum was keen to create opportunities for the young. He wanted to “give back” out of gratitude for a fulfilling and rewarding professional and personal life.
He is survived by his widow Andree, who will find life “very much the poorer” in his absence, and daughters Sophie and Joelle.