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IfcQuantityArea

Definition from buildingSMART: A physical quantity, IfcQuantityArea, that defines a derived area measure to provide an element's physical property. It is normally derived from the physical properties of the element under the specific measure rules given by a method of measurement.

EXAMPLE: An opening may have an opening area used to deduct it from the wall surface area. The actual size of the area depends on the method of measurement used.

HISTORY New entity in IFC Release 2.x. It replaces the calcXxx attributes used in previous IFC Releases.

EXPRESS specification:

ENTITY IfcQuantityArea
SUBTYPE OF ( IfcPhysicalSimpleQuantity);
AreaValue  :  IfcAreaMeasure;
WHERE
WR21  :  NOT(EXISTS(SELF\IfcPhysicalSimpleQuantity.Unit)) OR (SELF\IfcPhysicalSimpleQuantity.Unit.UnitType = IfcUnitEnum.AREAUNIT);
WR22  :  AreaValue >= 0.;
END_ENTITY;

Attribute definitions:

AreaValue  :  Area measure value of this quantity.

Formal Propositions:

WR21  :  If a unit is given, the unit type shall be area unit.
WR22  :  A valid area quantity shall be greater than or equal to zero.

Inheritance graph

ENTITY IfcQuantityArea;
ENTITY IfcPhysicalQuantity;
Name  :  IfcLabel;
Description  :  OPTIONAL IfcText;
INVERSE
PartOfComplex  :  SET [0:1] OF IfcPhysicalComplexQuantity FOR HasQuantities;
ENTITY IfcPhysicalSimpleQuantity;
Unit  :  OPTIONAL IfcNamedUnit;
ENTITY IfcQuantityArea;
AreaValue  :  IfcAreaMeasure;
END_ENTITY;