Dag Boutsen graduated in 1986 as an architect at Sint-Lucas School of Architecture in Brussels. From 1987 until 2009 he was Leading Architect at A.U.A.I (Atelier d’Architecture, d’Urbanisme et d’Informatique L. Kroll), renowned for its urban planning and architectural constellations, research and participation in international competitions.

Furthermore he worked as a project architect in Zambia, Lusaka. Since 1991 he is working at Sint-Lucas School of Architecture, first teaching design courses, later on as member of the board and Head of Department. With the inauguration of Sint-Lucas School of Architecture as the Faculty of Architecture at KU Leuven in November 2012, he became the first Dean of this Faculty. In 2017 his second mandate as Dean of the Faculty started.