Conrad was the second son of Anna and Bernard Harrington, born in 1884 in Montreal. To his sisters Clare and Ruth, and older brother Eric, many other siblings were soon added: Edith, Lois, Eva (Constance Eva), Bernard and William. The large family spent summers at Little Metis near to Birkenshaw, his grandfather’s home there. He was educated at Montreal High School and also attended the Royal Military College in Kingston, Ontario. He earned his B.Sc. at McGill where his father taught and his grandfather was principal. He married Muriel Theodora Featherstonhaugh, a graduate of Trafalgar School for Girls. They had two sons, Conrad Featherstonhaugh who himself went on to become chancellor of McGill and Eric, named after his father’s older brother who had died young. Their daughter was named Janet Geraldine.

Conrad D. joined the Anglin Norcross Corporation Ltd. (then known as Byers and Anglin) in 1907 and eventually became vice president, having been the head of the corporation’s subsidiary branches in Quebec and Ontario. Some of the most important construction projects in Eastern Canada, including the Royal York Hotel and the Canadian Bank of Commerce Building in Toronto (both among the largest buildings in the British Empire at the time), as well as the Church of St. Andrew and St. Paul in Montreal, the Supreme Court in Ottawa, and the Chateau Frontenac in Quebec, were built by his company. He was also a president of the Montreal Board of Trade and of the Canadian Construction Association. At McGill he was a Representative Fellow in Applied Science for a number of years, retiring in 1930 from that position.

During the war years he worked in civilian war service as a construction engineer and work at the Naval Training Centre in Halifax, N.S. and Dominion Arsenals in Quebec City was under his personal supervision. He resided at 24 Ramezay Road in Westmount until his death January 26, 1943.