Cornell University’s Environmental Systems Lab, in partnership with the City of Ithaca, created the Energy Atlas Digital Twin to achieve the city’s goal of full carbon neutrality by 2030. The project targets the city’s 5,200+ buildings (responsible for over 300,000 metric tons of CO2 annually) by building a high-fidelity Urban Building Energy Model (UBEM). Using Bentley iTwin Capture for AI-driven 3D reconstruction from drone imagery, the team accurately extracted architectural data, saving an estimated 14,000 work hours in modeling labor. The UBEM platform, built on Cesium, allows stakeholders to prioritize cost-effective retrofits. This digital-first strategy enables pathways for up to 95% operational carbon reduction (or 104,000 metric tons of CO2 annually), establishing a scalable and replicable framework for accelerating energy transition in cities globally.