Juul-Sørensen was educated at the School of Architecture at the Royal Danish Academy of Fine Arts. After his graduation in 1985, he worked for various smaller architectural practices and the City of Copenhagen where he was involved in the planning of Ørestaden, before joining KHR Arkitekter in 1995 where he became a partner. In 2004 he left KHR Arkitekter to work for Arup's design office where he was employed until 2011 when he became director of Danish Design Centre.
Juul-Sørensen has mainly worked with design of public transport infrastructure. His works include the stations on the Copenhagen Metro (18 stations) (1995-2004), two stations of the City Tunnel in Malmö, Sweden (2002-2010), conceptual design for the Kolsås Line in Oslo, Norway (2004), and Flintholm Station in Copenhagen (2004).
- "Nille Juul-Sørensen ny direktør for Dansk Design Center". Dansk Design Center. Retrieved 2012-03-26.