Attic Walls Reappear, I Don't Want Them!

[Lighthouse]

In X5 I've created a pretty complicated two storey plan with lots of weird roofs, and I'm getting attic walls all over the place that I don't want.  I thought it was due to the complexity of the plan, so I tried playing with lots of variables but cannot get rid of them.  Finally I tried creating a very simple test plan with an auto generated roof, and discovered the same problem in that plan.  So maybe it has nothing to do with the plan complexity, since the test plan is a perfectly simple box.  Obviously I'm not understaning something about attic walls.  I do realize that I can choose not to display them in plan and camera views, but they still affect the plan whether displayed or not.  I would like to be able to permanently delete them, or better yet understand why they are being created.

 

In the attached plan, I'm simply trying to create a "notch" in the bottom right corner of the second floor, as if there was going to be a roof deck.  Even though the interior walls of the notch appear to hit the ceiling, it keeps generating outer attic walls to fill in the notch.  Can anyone explain why this is?  I've already wasted a few hours on this.  Thanks!

test plan.zip

[glennw]

Default Settings...Walls...General Wall...Auto Rebuild Attic Walls - uncheck.

[Lighthouse]

Wow, never knew that was there!!  You are the best, much thanks