After graduating from the Ecole des Arts Décoratifs de Strasbourg, Jean Haas began by teaching art and working as a graphic designer at the Theatre National de Strasbourg under the direction of Jean-Pierre Vincent until 1975. He then became a scenographer and set designer for the theater. He has lived in Paris since 1981 and works in France and abroad (Germany, Switzerland, Japan, Portugal, Italy, and Belgium). He has collaborated with many theater directors such as Bruno Bayen, Louis-Charles Sirsacq, Hans Peter Cloos, Alain Françon, Bernard Sobel, Jean-Louis Thamin, Jacques Nichet, Didier Bezace, Jean-Louis Jacopin, Claude Regy, Chantal Morel, Joel Jouanneau, Christian Colin, Pierre Strosser, Jerome Savary, Brigitte Jacques, Guy Delamotte, Vincent Goeathals, Philippe Adrien, and Patrick Kerbrat.
Between 1980 and 1990, Jean Haas worked in the music industry designing sets for various artists, including Philippe Chatel, Michel Berger, France Gall, Barbara, Veronique Samson, Johnny Halliday, Diane Dufresne, Yves Duteil, Francis Cabrel, and Jacques Higelin.