 Following this he moved to Melbourne and joined the practice of Stephenson & Turner, where he was to become a senior draftsman by the 1940s.Stephenson & Turner's health buildings of the 1930s have been noted as creating the 'foundations for Australian functionalist modernism'.While with the practice Muir was to work on health buildings such as the 'perfectly styled', Maternal and Infant Welfare Pathological Block (1939) at The Royal Women's hospital and the Walter and Eliza Hall Institute Building (1939) at the Royal Melbourne Hospital.