In 1899, at the age of twenty-nine, he began to teach at the Kunstgewerbeschule, now University of Applied Arts Vienna. He designed the Vienna arts exhibition for the 1900 Paris Universal Exposition, which exposed the Secession style to an international audience. In 1899, he also designed the Eighth Exposition of the Secession, one of the most important exhibitions it, due to its international participants. In addition to works by Secession artists, it featured works by the French artist Jules Meier-Graefe, the Belgian Henry van de Velde, The Scottish Charles Ashbee, and especially the works by the Scottish designers Charles Rennie Mackintosh and Margaret Macdonald Mackintosh from Glasgow. This exhibit included a group of model houses in the Hohe-Wart neighborhood of Vienna which displayed features of Arts-and-Crafts movement, including windows divided in small squares, and the gable roof.