8.16.3.12 IfcPropertySingleValue

8.16.3.12.1 Semantic definition

The property with a single value IfcPropertySingleValue defines a property object which has a single (numeric or descriptive) value assigned. It defines a property - single value combination for which the property Name, an optional Description, and an optional NominalValue with measure type is provided. In addition, the default unit as specified within the project unit context can be overridden by assigning an Unit.

The unit is handled by the Unit attribute, see Table 8.16.3.12.C for an example of various single value properties:

• If the Unit attribute is not given, then the unit is already implied by the type of IfcMeasureValue or IfcDerivedMeasureValue. The associated unit can be found at the IfcUnitAssignment globally defined at the project level (IfcProject.UnitsInContext).
• If the Unit attribute is given, then the unit assigned by the Unit attribute overrides the globally assigned unit.

Name	NominalValue	Type (through IfcValue)	Unit
Description	Manufacturer "A" door	IfcLabel	-
PanelThickness	0.12	IfcPositiveLengthMeasure	-
ThermalTransmittance	2.6	IfcThermalTransmittanceMeasure	W/(m2K)

8.16.3.12.2 Entity inheritance

1. • IfcPropertyAbstraction
2. • IfcProperty
   • IfcExtendedProperties
   • IfcPreDefinedProperties
   • IfcPropertyEnumeration
3. • IfcSimpleProperty
   • IfcComplexProperty
4. • IfcPropertySingleValue
   • IfcPropertyBoundedValue
   • IfcPropertyEnumeratedValue
   • IfcPropertyListValue
   • IfcPropertyReferenceValue
   • IfcPropertyTableValue

8.16.3.12.3 Attributes

#	Attribute	Type	Description
IfcPropertyAbstraction (1)
	HasExternalReferences	SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects	Reference to an external reference, e.g. library, classification, or document information, that is associated to the property definition.
IfcProperty (8)
1	Name	IfcIdentifier	Name for this property. This label is the significant name string that defines the semantic meaning for the property.
2	Specification	OPTIONAL IfcText	URI reference to a location with semantic definition or informative text to explain the property.
	PartOfPset	SET [0:?] OF IfcPropertySet FOR HasProperties	Reference to the IfcPropertySet by which the IfcProperty is referenced.
	PropertyForDependance	SET [0:?] OF IfcPropertyDependencyRelationship FOR DependingProperty	The property on whose value that of another property depends.
	PropertyDependsOn	SET [0:?] OF IfcPropertyDependencyRelationship FOR DependantProperty	The relating property on which the value of the property depends.
	PartOfComplex	SET [0:?] OF IfcComplexProperty FOR HasProperties	Reference to the IfcComplexProperty in which the IfcProperty is contained.
	HasConstraints	SET [0:?] OF IfcResourceConstraintRelationship FOR RelatedResourceObjects	User-defined constraints for the property.
	HasApprovals	SET [0:?] OF IfcResourceApprovalRelationship FOR RelatedResourceObjects	User-defined approvals for the property.
Click to show 9 hidden inherited attributes Click to hide 9 inherited attributes
IfcPropertySingleValue (2)
3	NominalValue	OPTIONAL IfcValue	Value and measure type of this property.
4	Unit	OPTIONAL IfcUnit	Unit for the nominal value, if not given, the default value for the measure type (given by the TYPE of nominal value) is used as defined by the global unit assignment at IfcProject.

8.16.3.12.4 Examples

• 

  Structural Curve Member

• 

  Linear Placement Of Signal

8.16.3.12.5 Formal representation

ENTITY IfcPropertySingleValue
 SUBTYPE OF (IfcSimpleProperty);
	NominalValue : OPTIONAL IfcValue;
	Unit : OPTIONAL IfcUnit;
END_ENTITY;

8.16.3.12.6 References

• IfcSimpleProperty