You can set the elevation base point from which an elevation tag reports its value.
Elevation Base has been added as a built-in type parameter for design and fabrication MEP segment tag family categories. You can specify the Elevation Base in the Type Properties dialog or the Family Type dialog in the Family Editor. The options are Project Base Point, Survey Point, or Relative.
This feature was suggested by customers on the
Ideas forum and is described on the
product road map.