We have a situation where the interior side of the curtain wall will be a wood finish mullion and the exterior will be aluminum. We are trying to figure out a way to make this happen in the mullion family so it's all modeled in one curtain wall instance. BTW, I'm not talking about the way curtain wall families currently call "interior mullions" as the ones occurring inside the curtainwall (not head, jamb, or sill mullions). I'm talking about splitting all the mullions material in the plane of the glazing panel - interior of the building/exterior of the building.
The only way we've been able to model this condition is with two curtain wall instances - one with the wood mullions and glass panels, and the other with the aluminum mullions. The problem is if the curtain wall is modified (location in plan, length or width, or mullion grid pattern, etc.) we now have to make these modifications in two parallel families.
It would be a much better workflow if Revit mullion families could be setup with a different "interior finish" and "exterior finish" material. The break between interior and exterior could happen automatically wherever the panel offset occurred.
Thanks!