The "From Room" set for the door or window in the last phase of the project.
Assembly: RevitAPI (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0)
Field ValueThe "From Room" set for the door or window in the last phase of the project. a null reference ( Nothing in Visual Basic) if the FamilyInstance is neither a door nor a window, or if the door or window leads to a space where there is no room (an exterior space or interior space with no room defined). Also a null reference ( Nothing in Visual Basic) if there is no target room assigned to the last phase.
Revit automatically calculates the "From Room" for a given door or window. This is the default shown when creating a door or window schedule and adding the "From Room" properties. The user can opt to swap the "From Room" and "To Room" values via the schedule if they choose. The method FlipFromToRoom also can be used to swap the values.