[3] Tuomey studied architecture at University College Dublin (UCD), graduating in 1976 and then joining Stirling Wilford & Associates.
[4][5] In 1988 he founded In 1991 he was the managing director of Group '91 Architects, who oversaw the transformation of Temple Bar, Dublin.
[6] O'Donnell and Tuomey won the Royal Institute of the Architects of Ireland (RIAI) gold medal twice.
[7] According to Architectural League of New York, they are "noted for their expressive form-making, designing buildings that reveal the integrity of their construction and their relationship to the physical and historical context.
[11][12] Tuomey lives in Rathmines with his wife and professional partner Sheila O'Donnell.