Digital twins create a digital replica of a physical building that actually behaves like the real structure and provides crucial information on real life performance, enable us to better understand how our buildings are performing and simulate how they may perform in the future under a range of scenarios. Digital twin technology gives you a visual prototype of the building that allows you to measure it, allows you to test, and allows you to experiment on it without having to experiment on a real building. This digital twin technology can improve energy resilience, reduce operating costs, increase resource efficiency, and help to decarbonize our buildings. These are results of the combined building simulation and machine learning of systems like the Intelligent Communities Lifecycle, or ICL Environmental Digital Twin which then provide insights on energy use, waste heat, renewables, and occupant comfort and even transport connectivity. Any gaps in real world data can be filled with projections developed by the intelligent digital twin itself.