IfcPropertySingleValue

Natural language names
Merkmal mit Einzelwert
Property Single Value
Propriété à valeur simple
Change log
ItemSPFXMLChangeDescription
IFC4 Addendum 1 4.0.1.0
    IfcPropertySingleValue
      HasConstraintsADDED
      HasApprovalsADDED
IFC4X3_ADD2 to IFC4X4_draft
    IfcPropertySingleValue
      PartOfMaterialOrProfilePropertiesADDED
Semantic definitions at the entity
Entity 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 overriden by assigning an Unit.

The unit is handled by the Unit attribute, see Table 773 for an example of various single value properties:

 

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

Table 773 — Single value properties with values, measure types and units

HISTORY  New entity in IFC1.0.

IFC2x CHANGE  Entity has been renamed from IfcSimpleProperty.

IFC2x3 CHANGE  Attribute NominalValue has been made OPTIONAL with upward compatibility for file based exchange.

Attribute definitions
#AttributeTypeCardinalityDescription G
3NominalValueIfcValue? Value and measure type of this property.
NOTE  By virtue of the defined data type, that is selected from the SELECT IfcValue, the appropriate unit can be found within the IfcUnitAssignment, defined for the project if no value for the unit attribute is given.
IFC2x3 CHANGE  The attribute has been made optional with upward compatibility for file based exchange.
X
4UnitIfcUnit? 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. X
Inherited definitions from supertypes
Entity inheritance IfcSimpleProperty IfcProperty IfcPropertyAbstraction
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcPropertyAbstraction
HasExternalReferencesIfcExternalReferenceRelationship
@RelatedResourceObjects
S[0:?]Reference to an external reference, e.g. library, classification, or document information, that is associated to the property definition.
IFC4 CHANGE New inverse attribute.
X
IfcProperty
1NameIfcIdentifier Name for this property. This label is the significant name string that defines the semantic meaning for the property. X
2SpecificationIfcText? Informative text to explain the property. X
PartOfPsetIfcPropertySet
@HasProperties
S[0:?]Reference to the IfcPropertySet by which the IfcProperty is referenced.
IFC4 CHANGE  New inverse attribute to navigate from IfcProperty to IfcPropertySet with upward compatibility for file based exchange.
X
PropertyForDependanceIfcPropertyDependencyRelationship
@DependingProperty
S[0:?]The property on whose value that of another property depends. X
PropertyDependsOnIfcPropertyDependencyRelationship
@DependantProperty
S[0:?]The relating property on which the value of the property depends. X
PartOfComplexIfcComplexProperty
@HasProperties
S[0:?]Reference to the IfcComplexProperty in which the IfcProperty is contained.
IFC4 CHANGE  The cardinality has changed to 0..n to allow reuse of instances of IfcProperty in several IfcComplexProperty with upward compatibility for file based exchange.
X
HasConstraintsIfcResourceConstraintRelationship
@RelatedResourceObjects
? S[0:?]User-defined constraints for the property. X
HasApprovalsIfcResourceApprovalRelationship
@RelatedResourceObjects
? S[0:?]User-defined approvals for the property. X
PartOfMaterialOrProfilePropertiesIfcExtendedProperties
@Properties
S[0:?]Reference to the IfcMaterialProperties by which the IfcProperty is referenced. X
IfcSimpleProperty
IfcPropertySingleValue
3NominalValueIfcValue? Value and measure type of this property.
NOTE  By virtue of the defined data type, that is selected from the SELECT IfcValue, the appropriate unit can be found within the IfcUnitAssignment, defined for the project if no value for the unit attribute is given.
IFC2x3 CHANGE  The attribute has been made optional with upward compatibility for file based exchange.
X
4UnitIfcUnit? 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. X
Formal representations
XML Specification
 <xs:element name="IfcPropertySingleValue" type="ifc:IfcPropertySingleValue" substitutionGroup="ifc:IfcSimpleProperty" nillable="true"/>
 <xs:complexType name="IfcPropertySingleValue">
  <xs:complexContent>
   <xs:extension base="ifc:IfcSimpleProperty">
    <xs:sequence>
     <xs:element name="NominalValue" nillable="true" minOccurs="0">
      <xs:complexType>
       <xs:group ref="ifc:IfcValue"/>
      </xs:complexType>
     </xs:element>
     <xs:element name="Unit" nillable="true" minOccurs="0">
      <xs:complexType>
       <xs:group ref="ifc:IfcUnit"/>
      </xs:complexType>
     </xs:element>
    </xs:sequence>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcPropertySingleValue
 SUBTYPE OF (IfcSimpleProperty);
  NominalValue : OPTIONAL IfcValue;
  Unit : OPTIONAL IfcUnit;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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