Following the retirement of John Campbell in 1922, Mair was appointed Government Architect, a position which he held until his retirement in 1942. John Thomas Mair (1876-1959) was born in Invercargill and began his career with the New Zealand Railways on the staff of the Office Engineer, George Troup. In 1906 he travelled to the United States of America where he studied architecture at the University of Pennsylvania. A notable commission resulting from this American experience was the Romanesque Presbyterian First Church, Invercargill (1915). He became a Fellow of the Royal Institute of British Architects in 1940.