Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
I've filled an issue at NREL/EnergyPlus#10103 to address this corner case. The floor and ceiling are perfectly matching with 14 vertices, but the issue that you have a non-convex surface here, and EnergyPlus will stop trying to remove colinear vertices as soon a surface is deemed non-convex. Your floor is processed as being 7 vertices but the roof stays at 14 vertices because it finds a non-convex situation before it even gets to the colinear vertices, and it fails.
This is the floor:
And logically, the reversed ceiling:
I've included more information on the issue itself if you are curious.
The fix is to break both your floor and ceiling surfaces into two rectangular surfaces.. (Ideally you also do not want to make non-convex zones...)
