Byrne, Thomas Joseph (1876–1939), architect, was born 15 November 1876 in Kingston upon Thames, Surrey, son of Richard Byrne (d. c.1876), who served with the Royal Irish Fusiliers, and Harriet Byrne (née Knight). He was articled (1892) to Edward Carter, ARIBA, in London. From 1895 to 1899 he worked in Drogheda, Co. Louth, in the office of Anthony Scott (1845–1919), before returning to Carter's office. He subsequently became assistant architect with the London county council, where he worked on fire stations, Rowton houses and hostel accommodation for working men; he lived for some time in one of the hostels to test its practicality for those for whom it was designed, which stimulated his interest in housing.
Returning to Ireland, he held the dual office of clerk and architect to South Dublin rural district council (1901–19). He pioneered high standards in public housing, building in Chapelizod, Tallaght, Kilmainham, Rathfarnham, and elsewhere. Influenced by the Arts and Crafts movement, he used local materials and designed attractive labourers' cottages, which were economical, well built, commodious, and planned with large rear gardens, so that tenants were able to grow their own produce. Other works included the Carnegie libraries at Clondalkin (1910–11) and Ballyboden (1910–11). Around 1918 he was nominated by the RIAI as one of three assessors of the government-sponsored architectural competition for housing schemes. As housing inspector to the local government board (1919–23), he was recognised as a leading authority in the planning of small houses. Appointed principal architect to the board of public works (1923–39), he represented the Irish Free State at the 1923 conference on housing and town planning in Gothenburg, Sweden.
He was responsible for the restoration of numerous public buildings in Dublin which had been damaged during the conflicts of 1916–23, including the General Post Office (1925–32), and two masterpieces by James Gandon (qv), the Four Courts – rebuilding its great dome in reinforced concrete and clad with copper as in the original (1925–32) – and the Custom House (1925–9); he preserved their facades while radically redesigning their interiors. As a member of the city decorations sub-committee for the eucharistic congress of 1932, he introduced floodlighting to Dublin, in Phoenix Park, and was awarded a gold medal in recognition of his services. He was associated with Edward Lutyens (1869–1944) in the planning of the War Memorial Park at Islandbridge, Dublin (1937). Responsibility for building Dublin airport was given to the Office of Public Works, and Byrne had the task of interviewing suitable candidates. Desmond FitzGerald (qv) was appointed (1936) and with his team of young architects produced a pioneering design in the International Style (completed 1940). Byrne was also involved in the construction of other new airports at Baldonnell, Co. Dublin, and Rineanna (Shannon airport), Co. Clare.
Byrne was a stimulating lecturer, external examiner in architecture to NUI, and a member of the Industrial Research Council (1936). Elected member (1915) and fellow (1921) of the RIAI, he served as council member (1923, 1929, 1930, 1933, 1935, 1938–9) and vice-president (1926, 1937). He was also elected ARIBA (1900), member (1914) and president (1923–4) of AAI, and member (1917) and council member (1930–31) of ICEI, and was a founder member (1929) and vice-chairman (1929–39) of the Institute of Christian Art.
Silver-haired and handsome, he had a quiet unassuming air which belied an extremely active mind, remarkable memory, and shrewd judgement. His elder daughter Ethna, in the charming memoir of her childhood Ethna Mary twice (published under the pseudonym ‘Ethna Bee Cee’), described him as compassionate but aloof, uncommunicative, absorbed in thought, and not in the least demonstrative. His professional commitments allowed little time for recreation though he was an avid reader and loved the works of Charles Dickens. Interested in anything mechanical, he was one of the first in Ireland to own a car. He suffered ill health and later in life moved to 11 Terenure Rd, Rathgar, Dublin, where he died 27 January 1939. He was buried in Glasnevin cemetery, Co. Dublin. His family papers are preserved in the IAA. He married (1901) Mary Ellen Scott, elder daughter of Anthony Scott; they had at least two sons and two daughters. Two of his sons became engineers; his daughter Ethna Mary Byrne-Costigan (qv) was lecturer in Romance languages at UCC.