Detailed Surface - Outside Boundary Condition, Zone or Surface ?

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I'm modeling a model with 2 thermal zones on Euclid for EnergyPlus Simulation. For the correct heat transfer of the zones can I delete one surface of the the zone 1, and define the surface of the zone 2 with Outside Boundary Condition Zone, and zone 1? I think it is possible, however i didn't see anybody doing in this form. Or I have to have the Outside Boundary Condition always between surfaces duplicates (onde for 1º zone, and the second of the 2º zone). Thank you!