IfcPropertySingleValue

IfcPropertySingleValue

Definition from IAI: A 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, the value with measure type (and optional the unit) is given.

The unit is handled by the Unit attribute:

If the Unit attribute is not given, than 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, the unit assigned by the unit attribute overrides the globally assigned unit.

Examples of a property with single value are:

Name	NominalValue	Type (through IfcValue)	Unit
Description	Manufacturer "A" door	IfcLabel	-
PanelThickness	0.12	IfcPositiveLengthMeasure	- (unit taken from IfcProject.UnitsIn Context)
ThermalTransmittance	2.6	IfcThermalTransmittanceMeasure	W/(m²K)

HISTORY: New entity in IFC Release 1.0.

ISSUES: See issue log for changes made in IFC Release 1.5 and for changes made in IFC Release 2x. The entity has been renamed from IfcSimpleProperty in IFC Release 2x and includes the concept of the previous IfcSimplePropertyWithUnit.

EXPRESS specification:

ENTITY IfcPropertySingleValue

SUBTYPE OF (

IfcSimpleProperty);

NominalValue

IfcValue;

Unit

OPTIONAL IfcUnit;

END_ENTITY;

Attribute definitions:

NominalValue	:	Value 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 unit assignment (IfcUnitAssignment) defined for the project if no value for the unit attribute is given.
Unit	:	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.