The Art Nouveau movement emerged as a reaction against the monotonous mass production of the industrial era, proposing a design philosophy that harmonized art and craftsmanship with functionality. Through the concept of the Gesamtkunstwerk (total work of art), Art Nouveau designers established a unified design language characterized by originality and distinct formal qualities. This study examines fireplaces as focal points within Art Nouveau interiors to illustrate the integration of coherence and functionality—key concepts in interior architecture education. Specifically, the relationship between fixed elements (fireplaces) and movable elements (furniture) is evaluated to offer an alternative perspective on spatial organization. Comparative analysis reveals that, unlike many contemporary designs where fireplaces often appear detached from the overall interior, Art Nouveau fireplaces serve as unifying elements through material harmony and formal unity. Utilizing qualitative research methods, this study compiles and analyzes relevant examples to demonstrate how formal and material integrity contributes to visual and functional comfort. Ultimately, these analyses aim to enhance interior architecture students' understanding of holistic design by emphasizing the unifying role of the fireplace in the interior-furniture relationship.

Keywords: Art Nouveau, Interior Design, Spatial Integrity, Fireplace, Furniture Design, Holistic Design