Art Nouveau architecture during the last century experienced drastic change of attitude – from complete denial to glorification. However, many publications still repeat the same stereotypes of style assessment, focusing on the decorative layer as the seemingly main feature of style. Some significant values of Art Nouveau heritage are still only partially or incompletely recognized. In this paper, several less known examples of Art Nouveau heritage in France, in particular, in the cities of Orléans, Dunkirk and Lille are analysed. The architectural-artistic qualities of these buildings are revealed in the context of both French and wider cultural heritage. Art Nouveau, having been the origin and basis of the entire stylistic system of modern architecture, completely meets the principles of contemporary Baukultur ideas.