Save the simple family from the previous section as a new family and delete the door panel.
Work in the Ref. Level Plan View with the workplane set to Ref. Level. We now add to the definition of the hinge to enable us to bring a (possibly elaborate) door panel into the family and use that instead of a simple extrusion. Create a locked angular parameter of 90° so that we can lock an angular dimension at 90° by applying a label.
Create a second reference line with one of its ends close to the hinge point. Aligned dimension the between the vertical reference plane defining the hinge point and the end of the reference line closest to the hinge point. Do the same with the horizontal reference plane defining the hinge point.
Dimension the angle between the two reference lines. All three dimensions are shown below.
Label the angular dimension with the 90° lock parameter, and label the two linear dimensions with the 0mm lock parameter.
Unlock the parameter that defines the door jamb face offset (dj1_m_fo).
Flex the family to make sure the hinge behaves correctly. Note how the two reference lines remain orthogonal as the door opening angle is changed. The hinge point is now fully defined for us to host imported door panels to it.
Save the file.