In this study, the authors investigated the smart polymer-dispersed liquid crystal (PDLC) window film as an innovative building envelope technology supporting Taiwan’s 2050 Net-Zero Emissions Pathway through comprehensive laboratory characterization, durability assessment, full-scale experimentation, and building energy simulation. Laboratory measurements demonstrated dynamic optical performance with visible light transmittance varying from 87.68% (transparent state) to 61.07% (shading state) and solar heat gain coefficient (SHGC) decreasing from 0.8246 to 0.6630, achieving a 16.16% solar heat gain reduction. Durability testing validated stable optical properties after 8000 switching cycles and accelerated weathering equivalent to five years under Taiwan’s climate conditions. Full-scale building experiments confirmed 5% air-conditioning energy consumption reduction in the shading state while maintaining optimal indoor illuminance between 500 and 700 Lux through an occupant-centric control system. Building energy simulation using Taiwan’s Building Energy Simulation Tool with Artificial Intelligence (BESTAI) platform revealed significant synergistic effects, with the comprehensive integration of PDLC technology, occupancy-based lighting control (35% energy reduction), and high-efficiency heating, ventilation, and air-conditioning (HVAC) systems (15% reduction) achieving cumulative 52% total energy savings, where PDLC contributed an additional 2% savings beyond other efficiency measures. Thermal environment monitoring demonstrated that the shading state created a delayed thermal response, effectively reducing direct radiative heat transfer to interior spaces. These findings validate the smart PDLC window film as a viable multi-functional solution offering simultaneous benefits in energy efficiency, thermal comfort optimization, visual quality enhancement, dynamic privacy control, and retrofit applicability for existing buildings, contributing to building sector decarbonization goals.