.AixLib.DataBase.Walls.Collections.OFD.BaseDataMultiInnerWalls .AixLib.DataBase.Walls.Collections.OFD.BaseDataMultiInnerWallsBaseDataMultiWalls in which 3 additional walls are added. This corresponds to the structure of AixLib.ThermalZones.HighOrder.House.OFD_MiddleInnerLoadWall.BuildingEnvelope.WholeHouseBuildingEnvelope.