Jack (baptised Giacomo) Antonio Coia was born on 17 July 1898 at 24 Salop Street, Wolverhampton, the eldest of the nine children of Giovanni Coia, the sculptor son of a farmer in Filignano near Naples. His mother Maria Ernesta Vannini was a dancer of Italian stock who was part of her stepfather’s circus dog act. The couple had met in Paris while Giovanni was making his way across France to Glasgow where other members of the family were already established. The Coias remained in Wolverhampton for a year before resuming the journey north with a barrel organ, earning a living with musical and dancing acts. On their arrival in Glasgow Giovanni opened an Italian café at Parkhead Cross. Jack attended St Michael's RC Primary School and, later, St Aloysius College, assisting in the café as soon as he was old enough.
In October 1915 John Gaff Gillespie took Coia into his office as an apprentice at a salary of 4 shillings a week without asking a premium. Coia first attended evening classes at Whitehill School in building construction and mathematics to qualify for entry to the Glasgow School of Architecture, then jointly run by Glasgow School of Art and the Royal Technical College under Professors Gourlay and MacGibbon: he did not have to serve in the First World War because of poor eyesight and enrolled as a part-time student in 1917. On leaving Gillespie's office he worked for a time with Alexander Nisbet Paterson and with Alexander Hislop. His studies were aided by gaining two prizes: the A Leslie Hamilton Memorial and the Haldane Travelling Scholarship, which enabled him to make a first study visit to Italy in 1923, spending his time mainly in Venice. He was admitted ARIBA on 3 March 1924, his proposers being James Lochhead, John Watson and William Brown Whitie.
Coia then moved to the office of Herbert A Welch and Hollis in London, but family problems caused him to return home in 1927. Gillespie had died in May 1926, soon after taking William A Kidd into partnership, and on hearing Coia was back in Glasgow Kidd appealed to him to return and assist in the reconstruction of the Smith warehouse as the Ca' d'Oro, for which Gillespie had left only sketch designs. Shortly after taking Coia into partnership, Kidd died in 1928 while the work was in progress. Coia inherited the practice which he continued as Gillespie Kidd and Coia, but as there was little business apart from the fitting of Leon's shop at 89 St Vincent Street, Coia joined the staff of Glasgow School of Art quickly becoming chief assistant instructor to Alexander Adam, then head of School.
In 1931 Coia approached Archbishop Donald Mackintosh for work on the programme of church extension then planned. This resulted in a series of important brick-built church commissions of continental inspiration and in about 1938, his senior assistant T Warnett Kennedy was taken into partnership. Kennedy was born c.1913 and was articled to Coia in about 1927 after an unhappy period with James Austen Laird. He remained with him thereafter apart from a short period with Honeyman and Jack. As a student he had been editor of the quarterly magazine 'Vista' published quarterly which included articles by Hans Poelzig, Ragnar Ostberg, R H Wilenski and other major names of the 1930s. Coia and Kennedy worked closely together but in Kennedy's words 'Jack thought with his fingers. He sketched at lightning speed. I pontificated on the emergence of abstract art … During the 1938 British Empire Exhibition we slept on the floor of the office an average of three nights a week.'
At the British Empire Exhibition Coia was initially commissioned to design the Roman Catholic Pavilion, a towered modernist church with external frescoes by Hugh Adam Crawford, but Thomas Smith Tait quickly brought Coia and Kennedy into his own team to design the Palace of Industry North. These prominent modernist structures brought a wider recognition of the practice’s abilities and in 1939 Glasgow Corporation commissioned an £130,000 school at Knightswood. In the same year the practice was returned to complete Gillespsie’s municipal buildings in Stirling. The increasing prosperity of the practice had been marked by a move into Burnet’s old office at 239 St Vincent Street in or about 1936. But after the Second World War broke out in September 1939 both these projects were abandoned although the contractors were already on site at Stirling. Although the outlook was black, on 21 November 1939 Coia married Eden Bernard (born Edith Marx) after her divorce from Harry Levingstone and set up house at 2 Clifton Street.
The partnership of Coia and Warnett Kennedy did not survive the war. The completion of St Columbkille’s at Rutherglen was the only significant work left in hand and Kennedy left: he was not called up, but was recruited by Sam Bunton to repair Dumbarton after the first air raids. When Italy entered the war in June 1940 Coia briefly lost control of the practice although born in Britain and a British subject, and much more seriously lost the practice archive to salvage (although he did manage to retain those records relating to his own practice in 1927). As soon as he could, he re-established the practice at 199 Bath Street, and perhaps to emphasise his commitment to it, he was admitted FRIBA on 20 May 1941, his proposers being Lockhart Whitford Hutson, Alexander Nisbet Malcolm and John Stewart.
Nevertheless Coia still found his Italian connections made him suspect and work was harder to come by than it had been for Kennedy and he spent more of his time studying for a degree in town planning. By 1942 maintaining a separate house and office had become unsustainable and the Coias moved to 7 Hamilton Drive where the basement became the office. Although it has been stated by Rogerson and others that the practice closed in 1940, the practice of Gillespie Kidd & Coia was at least nominally in existence throughout the war to retain the Knightswood and Stirling commissions, although the latter was not referred to in his 1941 nomination paper.
Lack of work resulted in the Coias suffering considerable financial hardship in the later years of the war, with Jack Coia's income coming mainly from work in the family café, such free time as he had being spent on obtaining a degree in town planning. But in 1945 Sam Bunton relieved the situation by asking him to help with the reconstruction of Clydebank. Kennedy preferred not to rejoin the partnership, and emigrated to Vancouver where he founded a building centre and became Mayor. Coia then took on as an apprentice Isi Metzstein, who was a refugee. In 1948 the practice moved out to Waterloo Chambers, 19 Waterloo Street and in 1954 Andrew MacMillan joined the practice from East Kilbride Development Corporation. By 1950 Coia had been elected AMTPI. In 1956 both house and office moved to 20 Park Circus, and in the course of the move a burst water pipe destroyed most of the practice drawings. (At this time John Peter Coia, Jack's much younger brother, was working in the practice, having undertaken his apprenticeship there from 1933 to 1938.) Thereafter Metzstein and MacMillan undertook most of the design work. The last major buildings by Coia himself were the magnificent St Laurence, Greenock (1950-54), St Michael’s, Dumbarton, (1952) and St Charles, Kelvinside (1959-60) where his design was developed by Andrew MacMillan and Joe Taylor.
Coia was elected ARSA in 1954 and full academician in 1962. He was a Vice President of the RIAS from 1964-65. He was appointed CBE in 1967 and awarded the Royal Gold Medal in 1969 followed by honorary degrees from the universities of Glasgow (1970) and Strathclyde (1976). In person he was in Patrick Nuttgens' words 'small, intense, unkempt, angry and bloody-minded', mainly as a result of his wartime hardships and the post-war decision not to complete the Stirling Municipal Buildings as Gillespie had designed them. The poverty of contemporary architecture, dissatisfaction with the competition system and the destruction of some of his favourite buildings also coloured his outlook in his later years, his views being trenchantly expressed at the Royal Fine Art Commission of Scotland of which he was for a time a member. In his retirement he spent much of his time at Glendaruel where he overtaxed his strength on ambitious gardening works. He died at 12 Winton Drive on 14 August 1981. His funeral service was held at St Aloysius, the homily being preached by his pupil Father Kenneth Nugent SJ.