He was of French extraction and moved to Massachusetts as a child. Hirons worked as a draftsman in the Boston architectural office of Herbert Hale from 1898 until 1901, before entering the Massachusetts Institute of Technology; on graduating in 1904 he received a Rotch Travelling Scholarship[2] to study at the École des Beaux-Arts in Paris. MIT's Paris prize enabled him to continue his European studies until 1909.
On his return, he established an architectural practice in New York with Ethan Allen Dennison (1881–1954).[3] Hirons and Dennison produced many commercial structures in the Beaux-Arts and Art Deco styles including;[4] Delaware Title & Insurance Company, Wilmington, Delaware; Federal Trust Company Building, Newark; City National Bank, Bridgeport, Connecticut; Home Savings Bank, Albany, New York; State Bank & Trust Company, West 43rd Street and 8th Avenue, New York; Beaux-Arts Institute of Design, 304 East 44th Street;[5] Suffolk Title and Guarantee Company Building, 90-04 161st Street, Queens, New York;[6] The Mechanics Bank, New Haven Connecticut; The National State Bank, Elizabeth, New Jersey; The Erie Trust Company, Erie, Pennsylvania; The Society for Savings, Hartford, Connecticut; Trenton Banking Company, and the Trenton New Jersey.[7] Their Childs Restaurant in Coney Island, New York (1923), employs colorfully glazed terracotta tiles in a fanciful resort style combining elements of the Spanish Colonial revival with numerous maritime allusions that refer to its seaside location".[8][9] The Davidson County Courthouse of 1936 by Hirons and Dennison (with involvement of Nashville local architect Emmons H. Woolwine) is listed on the National Register of Historic Places.
In 1929, Hirons formed a two-year partnership with F.W. Mellor of Philadelphia, and then practiced again under his own name until 1940, when he retired.
He designed many public buildings, including the Worcester Memorial Auditorium and the George Rogers Clark Memorial in Vincennes, Indiana.