Mary Laheen B Arch MUBC MRIAI RIBA graduated from the School of Architecture, University College Dublin in 1981.

She initially worked in New York with Al de Vido Associates. Later in San Francisco she became involved in documentary film making and investigating the role that film and video might play in the education of architects. She directed a short film about the Architect Louis Kahn and the Salk Institute in San Diego. Returning to Dublin she joined the practice of de Blacam and Meagher Architects, where she was the project architect for the New Library at CORK IT, which won the RIAI Gold Medal in 1997.  She set up Mary Laheen Architects in 1995; the practice has been involved in the design of schools, houses and commercial projects. In 1998 she began teaching at the School of Architecture, being primarily involved in the First Year Studio where she acted as Module Co-ordinator until 2007. Since that time she has been teaching in the third, fourth and fifth year studios.

 She completed a Masters in Urban and Building Conservation at UCD in 2005, and published her work from that period in a book about the cultural landscape of the Aran Islands, in Co. Galway.