Create New, Custom IFC Property

IFC Properties are additional (mostly IFC Type-specific) parameters assigned to an IFC Entity. Standard, so-called “IFC2x3 Schema” data are defined by buildingSMART and stored in property sets whose names begin with the prefix “Pset_”

You may wish to create a custom Property or Property Set (e.g. an office-standard Property Set).

1.In IFC Project Manager, click New.

2.In the appearing dialog box, enter a new custom Property Set name (Pset); or else choose from the list of existing Property Set names defined previously for the same element type (click the arrow icon to access this list). For example, if you are creating a new Property for an IfcWall, the list contains all the Pset names earlier assigned to other IfcWalls.

Note: To avoid errors (and to keep the standard property definition rules), do not use the standard “Pset” prefix when giving a name to your custom Property Sets.

3.Enter a new Property name.

4.Choose a Property type (single, enumerated, complex, etc.) as described in the following table.

Property type	Definition
Single Value	A property object which has a single (numeric or descriptive) value assigned.
Enumerated Value	A property object whose value is chosen from an enumeration.
Bounded Value	A property object which has a maximum of two (numeric or descriptive) values assigned, the first value specifying the upper limit and the second value specifying the lower limit
Table Value	A property object which has two lists of (numeric or descriptive) values assigned, corresponding to a table with two columns.
List Value	A property that has several (numeric or descriptive) values assigned, corresponding to an ordered list.
Reference Value (IfcCalendarDate only)	A property object which references to calendar date-type entity (day, month, and year).

5.Set the value type to label, text, integer, boolean, etc.

See also Unit Conversion for IFC Export

Value type	Definition
IfcAreaMeasure	REAL type value of the extent of a surface. Value must be set in square meters, but is recalculated at export based on Area Unit settings.
IfcBoolean	A defined data type of simple BOOLEAN type. Value: TRUE or FALSE.
IfcIdentifier	An identifier is an alphanumeric STRING (max. 255 characters) which allows an individual thing to be identified. It may not provide natural-language meaning.
IfcInteger	A defined data type of simple INTEGER type. The number of bits contained in the IfcInteger is unrestricted, but in practice it is implementation-specific.
IfcLabel	A label is the term by which something may be referred to. It is a STRING (max. 255 characters) which represents the human-interpretable name of something and shall have a natural-language meaning.
IfcLengthMeasure	REAL type value of a distance. Value must be set in meters, but is recalculated at export based on Length Unit settings.
IfcLogical	A defined data type of simple LOGICAL type. Value: TRUE, FALSE or UNKNOWN.
IfcMonetaryMeasure	REAL type value of an amount of money without regard to its currency. The currency unit can be set at Currency Unit settings.
IfcPlaneAngleMeasure	REAL type value of an angle in a plane. Value must be set in radians, but is recalculated at export based on Angle Unit settings.
IfcPositiveLengthMeasure	Length measure shall be greater than zero. Value must be set in meters, but is recalculated at export based on Length Unit settings.
IfcRatioMeasure	REAL type value of the relation between two physical quantities that are of the same kind. Input given in percent is expressed as a decimal value: e.g. 25% becomes 0.25.
IfcReal	A defined data type of simple REAL type. The domain of Real is all rational, irrational and scientific real numbers. Here the precision is unconstrained, but in practice it is implementation-specific.
IfcText	Alphanumeric STRING of characters which is intended to be read and understood by a human being. It is for information purposes only. No character number limitation.
IfcTimeMeasure	REAL type value of the duration of time periods. The time unit can be set at Time Unit settings.
IfcVolumeMeasure	REAL type value of the solid content of a body. Value must be set in cubic meters, but is recalculated at export based on Volume Unit settings.
More Types…	See the definitions at “alphabetical listing” > “Defined Types”: http://www.buildingsmart-tech.org/ifc/IFC2x3/TC1/html/index.htm

Note: All other “Measure”-type properties not listed in the above table are handled and exported without any unit settings.

•Newly created IFC data will appear in the defined Property Set or under “Classification References” in the IFC Project Manager, as well as in the element Settings dialog among the listed properties.

•Such newly created IFC data appear with a red X in front, meaning that you can delete them at any time.