Door & Window Orientation

Revit's native ToRoom/FromRoom properties swap when a door is flipped. These helpers are stable regardless of flip state — using geometric swing arc analysis to determine room relationships.

Swing-Based Detection

RoomTo() and RoomFrom() determine room relationships based on the physical swing arc geometry — the room the arc swings into is the "To" room. This is the most reliable geometric approach, but it may not always match the architectural intent. For example, in egress situations where code requires the door to swing toward the exit, the swing direction is opposite to the logical "entry" direction. In such cases, consider adding a shared parameter to explicitly tag the intended direction.

Room Access

fi.RoomAccess() / fi.RoomFrom()

Returns the room on the non-swing side — the side the door swings away from. Stable regardless of flips.

door.RoomAccess()   // → "Corridor"

fi.RoomDestination() / fi.RoomTo()

Returns the room the door swings into (based on swing arc geometry). Stable regardless of flips.

door.RoomDestination()  // → "Office 101"

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Handing & Hinge

fi.Handing()

Returns the handing code as seen from RoomFrom() — the non-swing side.

Since RoomFrom() is always the side the door swings away from, the observer always sees a Push door. This means Handing() will always return LH or RH:

Code	Meaning
LH	Left Hand — hinges on the left as seen from RoomFrom()
RH	Right Hand — hinges on the right as seen from RoomFrom()

door.Handing()    // → "LH" or "RH"

fi.HingeSide()

Returns "Left" or "Right" as seen from the Access Room.

door.HingeSide()  // → "Right"

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Flip State

fi.IsHandFlipped() / fi.IsFacingFlipped()

Direct wrappers for Revit's FamilyInstance.HandFlipped and FamilyInstance.FacingFlipped.

door.IsHandFlipped()    // → true / false
door.IsFacingFlipped()  // → true / false

tip

In string mode, use WhereParam("HandFlipped", "True") instead. This uses reflection and works even on List<Element>.

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Swing Arc

fi.FindSwingArc()

Returns the largest Arc found in the door's geometry — the physical swing arc in World Space.

var arc = door.FindSwingArc();
// arc.Radius, arc.Center, arc.GetEndPoint(0)

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Curtain Wall Detection

fi.IsStandardDoor()

Returns true if the door is hosted in a standard wall (Basic/Stacked), false if it's a Curtain Wall panel (glass door).

door.IsStandardDoor()  // → true for standard doors
// false for curtain wall glass doors

.StandardDoor() — Collection Filter

Filters a FamilyInstance collection to exclude Curtain Wall hosted panels. Curtain wall doors don't carry standard properties like Level, Width, Height, Room, or swing geometry.

GetElements<FamilyInstance>("Doors")
    .StandardDoor()
    .Table();