Creating/Changing simple house layout works but with errors

Hi @Daan, how do I create new Revit elements each run and delete others? I prefer this option as this seems more dooable from my pov (relatively newbie here). I was thinking may be my error is because of flow control and I was looking to try “pass through” node.
Also I found this similar question but haven’t understood the solution yet. Python - Delete Elements Created & Recreate

Thanks