Glennie designed many buildings in Cape Town. He begun to practice in Cape Town in the early 1920s. A prominent Catholic, Glennie designed many buildings for the Catholic Church and was commissioned to design the Catholic University of Pope Pius XII at Roma, Basutoland.
Glennie was educated at Wynberg Boy's High School, Cape Town. He was articled to BAKER & MASEY in Cape Town from 1909 until 1911 but remained in the office working as an assistant. In about 1912 he won the Cape Institute of Architects' prize for measured drawings. In 1917 he left BAKER & FLEMING to set up independent practice in Cape Town. In the early years of practice Glennie executed a number of ecclesiastical works, houses and small scale commercial buildings. He quite soon obtained some major commissions, the first of these large works was the Exchange Building for Mann, George & Co in St George's St (1927), a sophisticated design with corner feature recessed for emphasis rising through all six floors. Glennie went on to design many well-known commercial buildings in Cape Town, such as the Reserve Bank in Wale St (c1928) and the Commercial Union Assurance building, St George's St (1930). He also designed the Royal Hotel at Beaufort West (1931).
Glennie was an enthusiast of old Cape buildings and one time secretary of The National Society for which he did many drawings of historic Cape buildings. A number of these were reproduced in Dorothea Fairbridge's Historical houses of South Africa (1922) and in GE PEARSE's Eighteenth century architecture in South Africa (1933).
In 1933 Glennie made an extensive overseas visit, studying buildings in England, Holland, France and Italy with a further year's travel and residence in England, America, Holland, Germany, Sweden and Italy. He returned to Cape Town, continuing to practise until 1953. He acted as senior associate architect on several schemes, a number in association with JZ SCHUURMANS-STEKHOVEN with whom he worked for instance on the Provincial Buildings (Wale St/Queen Victoria St/Long St/Dorp St) in 1940. Other late buildings by Glennie include Court Chambers for Syfrets Trust in Wale St (c1950).
Glennie's office was a popular place for students in training; LF McCONNELL was among those who gained office experience in Glennie's office. Glennie was also a co-founder of the South African National Botanic Gardens at Kirstenbosch.
In 1944 he entered partnership with TE EGAN, joined by H SIKKEL in 1946 (GLENNIE, EGAN & SIKKEL). He retired in 1953 and died in Cape Town.
FCIA; MIA; ISAA 1927; FRIBA 1936. (FRIBA nom papers (1936) 3364; RIBA Jnl Apr 1955:271 obit; SAAR Oct 1954:43 obit, port)