Commissioning (Cx) is not just a checkmark for a green building certification; it’s for owners who want to ensure that their building meets operational goals. Commissioning is the first step in maintaining your building’s systems and controls at peak performance. Energy modeling is an essential tool to achieving high performance in energy efficiency. Energy modeling can and should be used throughout the design process to optimize the building design for energy performance and reduced carbon emissions. Besides being part of the energy category of requirements for all green building rating tools, energy modeling is a valuable design tool which facilitates the integrated design approach. Building commissioning and energy modeling are essential tools for effective energy management of new and existing buildings.