bob323

Thank you much!  I've never paid attention to the Lower Wall Type When Split by Butting Roof nor used it!  Now I know what it does!  Again, thank you.

Eric, good news is that I edited the post per your suggestions (including attaching the plan itself).  Bad news is that I tried the fix which I THINK you recommended on the Roof dialog of the Wall Specs for the wall separating the main, upper and lower levels - i.e., I checked Lower Wall Type if Split by Butting Roof option and for the drop-down below that I selected Interior 6.  Seems to have made  no change at all to the results.  Any other suggestions?  Thx.

Post edited per Solver's request:

I have created a simple split-level concept plan (attached) with vaulted ceiling on the main level and am having trouble with how the generated interior/exterior wall surfaces display on the wall separating the main, upper and lower levels.  Pics 3 & 4 are with simple flat ceiling on the main level; however, Pics 1 & 2 are with Flat Ceiling Over This Room UNCHECKED and Use Soffit Surface for Ceiling CHECKED.  From the Full Camera view, you can see that the wall changes from interior to exterior at upper level.  Any hints on how to fix this?  I'm sure it's something simple that I'm overlooking.  Thx in advance for your help.

Split Level Test.plan