Shared Reference Point Tool

On the Autodesk Subscription Site, under the productivity tools for AutoCAD Civil 3D 2014, you will find the Shared Reference Point Tool.  There is an installer for Civil 3D, which runs from the Toolbox, and then a second installer to run on Revit.

The extension exports an XML from Civil 3D with X,Y, and Z coordinates, along with the corresponding rotation and units.  This reference point defines the relationship between the site and building.