4.8.1.6 Clearance Geometry

Elements requiring surrounding space for clearance provide a 'Clearance' representation. The reason for clearance space may be due to ventilation, maintenance, or other purpose. Examples of such elements include boilers and chillers. Such representation may be used for interference checks, where the 'Clearance' representation must not intersect with the 'Body' representation of other objects, though may intersect with the 'Clearance' representation of other objects.

The representation identifier of the clearance representation is:

Figure 234 illustrates an instance diagram.

Clearance GeometryIfcElementIfcProductDefinitionShapeIfcShapeRepresentationIfcGeometricRepresentationContextIfcLabelIfcLabel

Figure 234 — Clearance Geometry

mvdXML Specification
<?xml version="1.0" encoding="utf-8"?>
<ConceptTemplate xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="0fdc2380-9ef0-41e9-b0dc-f01fd2f77e6c" name="Clearance Geometry" applicableSchema="IFC4" applicableEntity="IfcElement">
  <Rules>
    <AttributeRule AttributeName="Representation">
      <EntityRules>
        <EntityRule EntityName="IfcProductDefinitionShape">
          <AttributeRules>
            <AttributeRule AttributeName="Representations">
              <EntityRules>
                <EntityRule EntityName="IfcShapeRepresentation">
                  <AttributeRules>
                    <AttributeRule AttributeName="ContextOfItems">
                      <EntityRules>
                        <EntityRule EntityName="IfcGeometricRepresentationContext" />
                      </EntityRules>
                    </AttributeRule>
                    <AttributeRule RuleID="Identifier" AttributeName="RepresentationIdentifier">
                      <EntityRules>
                        <EntityRule EntityName="IfcLabel">
                          <Constraints>
                            <Constraint Expression="Identifier[Value] = 'Clearance'" />
                          </Constraints>
                        </EntityRule>
                      </EntityRules>
                    </AttributeRule>
                    <AttributeRule RuleID="Type" AttributeName="RepresentationType">
                      <EntityRules>
                        <EntityRule EntityName="IfcLabel" />
                      </EntityRules>
                    </AttributeRule>
                    <AttributeRule RuleID="Items" AttributeName="Items" />
                  </AttributeRules>
                </EntityRule>
              </EntityRules>
            </AttributeRule>
            <AttributeRule AttributeName="Name" />
            <AttributeRule AttributeName="Description" />
          </AttributeRules>
        </EntityRule>
      </EntityRules>
    </AttributeRule>
  </Rules>
</ConceptTemplate>

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