Embed void in footing to cut wall geometry?

[draft1]

I have a project where I modeled an exterior walls (wall type properties vary) on a curb on a trench footing as a stacked wall. This solved some difficulties encountered early in the modelling process. Now that I’ve added columns and isolated footings, I’m looking for ideas on how to make the isolated footing geometry cut the trench footing (wall geometry).  I’m working with several ideas, but so far none have proven to be ideal.

I could use the wall opening tool which works OK on a straight-away, but many of the columns occur at complex intersections varying types of stacked walls.

I could use some kind of wall based generic void family. I haven't done this before and have not had success in my for this application.

Is it possible to embed a void family into the isolated footing family and have the void cut the wall (trench footing) on placement? If so, please suggest how to create said family. Thanks!

[draft1]

Workable idea:

I've added a void to a generic family and create types having the same dimensions as the isolated footings that I need to cut wall geometry. I'm placing generic (void) family geometry at the same locations as the isolated footing of the same type. Then I'm cutting the (trench) walls with the generic (void) family. 

I was hoping for a more elegant solution, but this'll do in a pinch.

[MostafaElashmawy]

Usually the isolated footing will cut the wall footing automatically. If that don't happen, join them or switch the join order.

[MostafaElashmawy]

Hi @draft1 

Let me know if above solved your problem.

Will be ready for further explanation.