Placement: According to Wall Reference Line

You can use this function when you are adding a wall which has a special line of the type REFERENCE.

A REFERENCE line can be defined for the walls in the wall library.

Note:

You can directly select either the outer surface of the exterior siding, center of frame or the interior finish as the reference line from the auxiliary menu, see Reference Line Quick Selection.
With the function Select Reference Line, any point of the wall structure cross section can be selected as the reference line.