Hello lawrencelam2000,
If you’re still looking for information about the Rooms, Interior Area layer or Rooms, Standard Area, here is the information from the documentation in the section called Room Labels:
"Rooms, Standard Area is measured from the center of interior walls that define the room and from either the outside surface or the outside of the Main Layer of exterior walls, depending on the Living Area To setting in the General Plan Defaults dialog. It is rounded to the nearest square foot or mm and does not include the area within bay, box and bow windows.
Rooms, Interior Area is measured from the inner surfaces of all the room's walls."
Hopefully this helps!