UA calculation failure in test_bldg_13

[weilixu]

In PR #1823, test_prm_baseline_bldg13 failed in the CI test.
Debugging reviewed that the failure is caused by Surface 1624 and Surface 1666, 2 RoofCeilings in plenum space, have construction assigned as Ffactor Ground Floor 4_005, a Construction:FfactorGroundFloor object.

Due to the assignment of FfactorGroundFloor construction, the uFactor cannot be calculated and the test failed this specific line.

Digging deeper in the test model file: bldg_13.osm, both Surface 1624 and Surface 1666 have no Construction assigned, and they both adjacent to a surface that has construction of Ffactor Ground Floor 4_005. It seems in this case, OpenStudio assigns the adjacent surface's construction as default for these two surfaces - and this causes the error in the failed line mentioned above.

I want to understand the intent of having a roof ceiling adjacent to a floor in this test case, since it was never a problem until now, especially the changes in PR #1823 has nothing to do with what we found here. - should I update the code to accommodate this behavior or modify the test file?