buildingSMART Forums

Door Swing Direction - confusion (IfcDoorTypeOperationEnum)

In the buildingSMART documentation, the door swing direction convention for left and right swing is the opposite from e.g. DIN standards.

Blockquote NOTE There are different definitions in various countries on what a left opening or left hung or left swing door is (same for right). Therefore the IFC definition terms may derivate from the local standard and may need to be mapped appropriately.

E.g. according to bSI this is SINGLE_SWING_LEFT


What is the recommendation? Follow the correct local definition and thus diverge from the bSI specs (e.g. modelling a left swinging door but still apply SINGLE_SWING_LEFT, even though it differs from BSI) or would you introduce a semantic contradiction: model as left swinging yet apply the SINGLE_SWING_RIGHT enumeration to be in line with BSI specs?

Is it not possible to achieve both correct local definition and correct IFC definition in certain cases? Just rotate the XY axis?

Whether the door opens inwards or outwards is determined by the local coordinate system of the IfcDoor, or IfcDoorStandardCase.

As a result, this is a SINGLE_SWING_LEFT of which viewed from the +Y is hinged on the left and swings to the left, outwards:


If I move the axes as follows … this is now a SINGLE_SWING_RIGHT with hinges on the right, opening to the right, inwards:


Same door, different operation, depending on the axes.