Phases in Autodesk Revit Architecture are distinct and separate milestones for the life of your project. For example, Existing, Demolition, and New Construction can be used to represent either a specific period or the status of the project at a specific milestone. Revit projects always have at least one phase and by default Existing and New Construction are already created. By default, any object created is placed in the New Construction phase. These default phases can be renamed, and you can add additional phases to your project.
Phases are commonly used when you have an existing building that is undergoing some refurbishment. Phases are used to differentiate among the existing, demo, and new construction. Phases are also ...