This paper examines the transformative impact of digital media on architectural spaces, particularly through projection façades that enable dynamic, interactive experiences. By integrating digital media into architecture, traditional built environments evolve into spaces that directly engage users, redefining the relationship between people and the urban landscape. Projection façades involve the direct projection of video media onto building exteriors, leverage light, and visual effects to alter the appearance and character of structures, creating immersive environments where physical reality and virtual imagery coexist. This study explores spatial interaction design through a combination of theoretical synthesis and case analysis, focusing on how projection façades facilitate unique, multi-sensory experiences that resonate with human perception and behavior. The research identifies essential elements of spatial interaction design and demonstrates that projection façades can function as visual communication tools and interactive platforms. The analysis of several cases shows that these installations contribute to creating meaningful urban experiences, positioning buildings as responsive, adaptive entities within the cityscape. While digital media’s role in spatial design has advanced in visual art contexts, its architectural applications remain underexplored. The study concludes with a call for further research into projection façades within architecture and interior design as the integration of digital media in spatial environments continues to expand, offering new possibilities for enriching urban life and enhancing the interactive potential of architectural spaces.