An architect prepares the architectural model in Autodesk Revit Architecture, applies the corresponding templates, visibility settings and filters, and then publishes the model to the design package file (.adsk). The imported model represents a gross area footprint of the building, with property and utility connection points.
The following high-level procedure is performed by an architect in Autodesk Revit Architecture to prepare the architectural model for sharing with AutoCAD Civil 3D.
For details, see the Revit Help.