Energy performance of buildings has become a major focus of sustainable development policies across the world. In India, building energy regulations are still evolving but have gained momentum through the Energy Conservation Building Code (ECBC) introduced by the Bureau of Energy Efficiency. The ECBC sets minimum energy performance standards for commercial buildings, focusing on envelope design, lighting efficiency, HVAC performance, and use of renewable energy. Several states have adopted or partially implemented these codes, though enforcement remains uneven due to variations in local governance capacity, lack of awareness among builders, and higher initial cost perceptions. In residential buildings, regulations are relatively less strict, and energy efficiency compliance is mostly voluntary through green building rating systems such as GRIHA and other certification programs. Rapid urbanization and rising cooling demand are pushing policymakers to strengthen mandatory compliance and promote passive design strategies suitable for India’s diverse climatic zones. In the United States, building energy regulations are largely driven by state-level policies rather than a single federal mandate. The federal government provides model