Spatial Element Get Default Location Method

Return Value

XYZ
The default location of the spatial element.

Exception	Condition
InvalidOperationException	The spatial element does not have a valid default location.

The default location is a point where a spatial element is placed when it is created automatically without specifying a point. The default location of a spatial element is identical to the center of the bounding box if it is located inside the boundary, otherwise Revit will try to find a point that is guaranteed to be inside the boundary using an internal algorithm.

Reference