As cities around the globe strive towards becoming “smart” and sustainable, the integration of green facades into smart building design has emerged as a viable solution to address several environmental challenges. This paper conducts a comprehensive review of current research and applications in green facades, analyzing their role in enhancing energy efficiency, improving indoor air quality, and contributing to overall building sustainability. The impact of green facades on reducing energy consumption, through natural insulation and shading, is explored in-depth, alongside their role in air purification and enhancing the aesthetic appeal of urban environments. Despite the potential of green facades, several gaps between theory and practice exist, including challenges in implementation, maintenance, and cost-effectiveness. This paper identifies these barriers and provides a robust discussion of potential solutions, which include technological innovations, policy support, and public awareness initiatives. Ultimately, the integration of green facades in smart buildings presents a significant step forward in creating sustainable urban environments, necessitating further research and action in this realm.