The technology "RESEARCHSUBJECT_STRUCTUREPRICEDECREASE" is what you want to look at (in game it is the TEC's modular architecture, a tier 1 tech in the civ tree)...
Every structure has this line:
isAffectedBySimilarModuleCostResearch
Setting the value to TRUE means that if that faction has a technlogy similar to modular architecture, that structure will be affected by said technology...
In theory, you could, for example, make the Vasari have cheaper factories, the TEC have cheaper extractors, and the advent have cheaper trade ports all via the same research modifier...you would not, however, be able to have 2 TEC technologies each reduce the cost of a different structure (or structures) unless one of those was culture centers....