Definition from buildingSMART: The IfcRelProjectsElement is an
objectified relationship between an building element and one projection element
that creates a modifier to the shape of the element. This relationship implies
a Boolean operation of addition for the geometric bodies of the building
element and the projection element.
The relationship is defined to be a 1:1 relationship, if a building
element has more than one projection, several relationship objects have to be
used, each pointing to a different projection element.
HISTORY New entity in Release IFC2x
Element at which a projection is created by the associated IfcProjectionElement.
Reference to the IfcFeatureElementAddition that defines an addition to the volume of the element, by using a Boolean addition operation. An example is a projection at the associated element.