Gülsün was born in 1945 and graduated from Istanbul Technical University's Faculty of Architecture in 1967. She was awarded her Ph.D. in 1973 from the same University. She was appointed associate professor in 1978 and full professor in 1988 at I.T.Ü. She has been chairing the "Architectural Design Group" in I.T.Ü. since January 1992.

She has been teaching for 20 years in I.T.Ü. as a studio supervisor in Architectural Design". She also lectures on Architectural Design Theories, Logic Models of Design, Architectural Morphology and Computer Aided Architectural Design (CAAD) at both undergraduate and graduate levels. She had led many research and design projects in I.T.Ü. Her main research areas are: Architectural Design Theories, Computer Applications in Architecture, Morphological Studies of House Forms, Gecekondus (Squatter Settlements), CAAD of Dwelling Units, Simulations of Parametric Design Procedures, Circulation in Buildings.

Among many projects, she designed many villas and apartment houses and led the design group of Trabzon Hotel (320 beds), the BEL-ERKO housing project (360 units), a co-operative housing project in Istanbul (600 units), and the Trabzon branch of T.C. Ziraat Bankasi.

She organised a symposium on "Housing for the Urban Poor" in September 1991 in Istanbul. The symposium was a joint organisation of I.T.Ü. and the European Network for Housing Research (ENHR). She has written two books on Architectural Design Theories (in Turkish). She is the co-editor of the Proceedings of Housing for the Urban Poor (in English). She was also on the Scientific Committee of the Second Symposium on Housing for the Urban Poor held in Birmingham, England in 1994. The number of her published papers is 55 (23 in English, 32 in Turkish).She is a member of the Turkish Chamber of Architects, CIB Working Commissions W55 and W78, ACADIA, IAPS, ENHR, ISA and EAAE. She has been on the Scientific Committee of the Scientific and Technical Research Council of Turkey (TÜBITAK), and the Building Research Group (YAG) since 1990.

She was a visiting scholar at the Martin Centre, Department of Architecture, Cambridge University in 1975-1976 and in 1991 as a British Council Scholar.She was the Vice Rector of Istanbul Technical University between September 1992 and November 1995. She has been awarded several prizes in national design competitions and has received several architectural teaching awards from the TAÇ Foundation. She has been invited to Queen's University of Belfast as a Visiting Professor in the academic years from 1993 to 1996 and has also been invited to be on the Editorial Board of "Open House International". She has been the Rector of Istanbul Technical University since 1996.