Most of enterable buildings or structures overall in Arma games had interior objects (tables, cabines, etc.). They added for the immersion and combat, but sometimes a mission designer wants to remove interiors because they doesn't fit to the idea, setting, events, etc.
*I suggest to add a new function to Arma3's library - removal of building's interior on selected floors. I understand that it may take more effort to produce accurately (giving parameters of floor numbers, etc), but, as outlined many times at BIF, Arma is a platform by itself, offering flexibility, diversity and opportunity.
A function like [ code example [Building'sID,[floorArray(enter 1 value -  not needed. Or all - for faster coding)] ] call BIS_fnc_removeInterior.
*Assuming that most/all buildings in Arma 3 Final will have proper interiors.