# 5.4.3.52 IfcRelContainedInSpatialStructure

## 5.4.3.52.1 Semantic definition

This objectified relationship, IfcRelContainedInSpatialStructure, is used to assign elements to a certain level of the spatial project structure. Any element can only be assigned once to a certain level of the spatial structure. The question, which level is relevant for which type of element, can only be answered within the context of a particular project and might vary within the various regions.

The containment relationship of an element within a spatial structure has to be a hierarchical relationship; an element can only be contained within a single spatial structure element. The reference relationship between an element and the spatial structure need not be hierarchical; that is, an element can reference many spatial structure elements.

Predefined spatial structure elements to which elements can be assigned are

Occurrences of the same element type can be assigned to different spatial structure elements depending on the context of the occurrence.

Figure 5.4.3.52.A shows the use of IfcRelContainedInSpatialStructure to assign a stair and two walls to two different levels within the spatial structure.

## 5.4.3.52.7 Formal representation

ENTITY IfcRelContainedInSpatialStructure
SUBTYPE OF (IfcRelConnects);
RelatedElements : SET [1:?] OF IfcProduct;
RelatingStructure : IfcSpatialElement;
WHERE
WR31 : SIZEOF(QUERY(temp <* RelatedElements | 'IFC4X3_DEV_9f90c1f0.IFCSPATIALSTRUCTUREELEMENT' IN TYPEOF(temp))) = 0;
END_ENTITY;