In the quest for sustainability, managing and optimizing energy consumption within green buildings has emerged as a critical area of focus. The complexity of factors affecting energy use demands more sophisticated analysis than what traditional methods offer. This study leverages the DEMATEL method to isolate crucial influencing factors. It employs the ISM method to map their logical interconnections, forming a comprehensive model of energy consumption determinants in green buildings. We identify building design, energy efficiency, and green technology as critical elements, with building design exerting the most influence (weight: 0.35). Through an in-depth fuzzy DEMATEL-ISM analysis, we develop specific energy-saving measures—such as design improvement and technology enhancement—that promise up to a 20% reduction in energy consumption. Our research introduces a groundbreaking green building energy management tool and provides a solid foundation for policy development and practical applications.