missing floor

A missing floor is an imaginary level of a building, whose assigned number between those of existing levels is skipped in the building's numbering system. Common examples are floors in Chinese buildings ending with the digit '4', or 13th floors in Western buildings.

While this floor type does not describe an actual physical object, it is sometimes used for reference purposes or diagrammatic purposes.

The missing element is a number in the naming sequence, not a physically absent slab or a destroyed story. Consecutive physical floors can therefore have a missing numbered floor between their labels.