Chiefly known as the architect of many of Philadelphia's public schools, Irwin T. Catharine was the son of Joseph W. Catharine, chair of the Philadelphia Board of Public Education and, no doubt, the encourager of his son's career. In 1903 Irwin T. Catharine received his Certificate in Architecture from Drexel Institute, where he trained with Arthur Truscott
. Almost immediately he found employment as an assistant draftsman with the Philadelphia Board of Public Education. By 1923 he had become architect for the Board and in 1931 was made Superintendent of Building, a position which he retained until his retirement in 1937, one year after his father's death. Although Catharine is cited for designing several of the Moderne style schools in Philadelphia, he is chiefly associated with the Administration Building for the Board of Public Education at 230-250 North 21st Street (1931).
Catharine joined the AIA in 1921 and served as the vice-president of the Pennsylvania Society of Architects in 1929.