Unchecking partofTotalFloorArea may cause OpenStudio area to be out of sync with EnergyPlus building area

In EnergyPlus thermal zones can be set to be included in the building area or not. Among other things this will be the basis of the building EUI value. In OpenStudio spaces can be set to be included in the floor area or not with space.partofTotalFloorArea. If some spaces in a zone have this checked while others in the zone don't OpenStudio reports a different area than EnergyPlus.

There is the start of code to hard set the floor area of the thermal zone but it isn't currently enabled.
https://github.com/NREL/OpenStudio/blob/3b0d232b5f99a2a331804a8f9762f32a99b1a56b/openstudiocore/src/model/ThermalZone.cpp#L1205-L1211

Test model EdgeCaseModel.osm exhibits this issue
https://github.com/NREL/OpenStudio/tree/misc_standard_report_measure_issues/openstudiocore/src/pat_app/Measures/StandardReports/tests

Here is some sample code to show out of sync values

# total building area
query = 'SELECT Value FROM tabulardatawithstrings WHERE '
query << "ReportName='AnnualBuildingUtilityPerformanceSummary' and " 
query << "ReportForString='Entire Facility' and "
query << "TableName='Building Area' and "
query << "RowName='Total Building Area' and "
query << "ColumnName='Area' and "
query << "Units='m2';"
query_results = sqlFile.execAndReturnFirstDouble(query)

# temp code to check OS vs. E+ area
puts "area test"
puts "E+ reported area is #{query_results.get}"
puts "OpenStudio reported area is #{model.getBuilding.floorArea}”

Here is output

area test
E+ reported area is 600.0
OpenStudio reported area is 500.0

Need time to discuss proper solution and there are ways to avoid this (don't mix checkbox for spaces within a zone), so this should not be addressed for OpenStudio 1.10.

Screenshot of model attached.

Start with the existing floor-area code in openstudiocore/src/model/ThermalZone.cpp at lines 1205-1211, then reproduce the mismatch using EdgeCaseModel.osm in the StandardReports tests. Compare the OpenStudio and EnergyPlus building-area outputs and review the discussion to agree on the proper solution. Done means the areas are consistent and the EdgeCaseModel case is covered by a regression test.