After graduating from University College Dublin in 1950, Tallon worked in the Office of Public Works under Raymond McGrath. In 1956 he joined Michael Scott’s office. He became a full partner in 1958 in the firm Michael Scott and Partners which later became Scott Tallon Walker (one of the largest architectural firms in Ireland) of which he has been Chairman since the retirement of Michael Scott in 1975. An unapologetic follower of Mies, Tallon’s work has been uncompromisingly modern. His two most visible works in this idiom are the RTE Radio Building and the Bank of Ireland Headquarters in Baggot Street (1968-1978) and the former P.J. Carroll’s Factory (1967-69) in Dundalk, County Louth. Between 1992 and 1995 he was responsible for the Dublin Civic offices on Wood Quay.