Originally from Athens, Greece, Cosmas studied film production at New York University and architecture at Catholic University in Washington, D.C. While living in Los Angeles between 1985 and 2005, Cosmas worked as a set designer, art director and for four short years as a production designer on over 50 theatrical features and television shows. Since 2005, Cosmas lives on the east coast and works exclusively as a set designer using Rhino and Zbrush for both 3d modeling and construction documents.
In the seventh season premiere of "Buffy the Vampire Slayer", a
background sign lists "Cosmas A. Demetriou" as a member of board of
trustees of Sunnydale High School.