Define additional property sets for IFC export

You can create additional property sets out of template attributes and user-defined attributes, define properties for the attributes, and bind the Tekla Structures property sets to IFC entities for IFC export. Tekla Structures saves additional property sets in configuration files. You can keep several configuration files in several locations. When Tekla Structures exports an IFC file, it reads the predefined property sets and the additional property sets.

Note:

If you have created additional property sets in a Tekla Structures version earlier than Tekla Structures 2022, only the property sets corresponding to the IFC objects types found in the Structural entity type category will be available in Tekla Structures 2022 or later. Property sets corresponding to object types located in other entity type categories (such as IfcCovering in Common) will need to be recreated.

Add a new IFC property set configuration file

On the File menu, click Export > IFC or IFC4.
Select <new> in the Additional property sets list and click the edit button .
If you have copied one of the predefined configuration files in the model folder, open that one instead.
In the Property Set Definitions dialog box, enter a name for the new configuration file in the Property set configuration file name box.
To add a new property set, under Property Set, click the add button .

If you are using an existing configuration file, you can also select one of the property sets in the Property Set list.

You can create several property sets in one configuration file. For example, you can add COGs, and start and end points on the part level, and scheduling information on the assembly level.

Note that you can also edit the property set name and description, or delete an existing property set. To do that, click or respectively.
In the displayed dialog box, type a name and a description for the property set, and click Create.
The property set name may contain any text, including spaces. The maximum length of the property set name is 255 characters. The name should not start with the "Pset_" prefix, because this prefix is reserved for the standard BuildingSMART property sets.
Select the desired entity type category in the Entities list.
Structural is the default category. When you select the category, the related IFC entities are displayed in the Select entity types list.
Select an entity type from the Select entity types list by selecting its check box.

When you do this, the Select attributes list shows the attributes that are available for the selected entity type.
Add the desired attributes from the Select attributes list by selecting the check boxes next to the attribute names.
The attribute is added to the List of all selected properties list on the right. This list shows which attributes are exported and in which format:
- You can add new attributes by entering an attribute name in the Attribute box in the Create/Modify property area and clicking the Add button.
- You can modify and remove attributes on the list by selecting the attributes on the list and clicking Modify or Remove.
Under Create/Modify property, define the attribute properties:
- Select Property type for the selected attribute.
  Here, always select Template attribute for those user-defined attributes whose name contains more than 19 characters. For example, select Template attribute for ASSEMBLY.USERDEFINED.PLANS_STATUS.
- Enter or modify the name of the selected attribute in the name box Name.
- Select the Type of the attribute. The Type can be one of the following: String (sequence of characters), Boolean(false or true), Integer (number without a fractional part), Measurement, Real (numbers that have decimal representations), or Time stamp.
- If the type of the user-defined attribute is Measurement:
  - You can select the Measurement type: Length, Area, Volume, Mass, Positive length or Count.
  - You can select the Conversion factor and Accuracy.
    User-definable accuracy allows better IFC file size optimization.
Click Save to save your modifications.

1) The entity groups where Tekla Structures attributes are written in the exported IFC file

2) The template attributes or user-defined attributes that you want to export for the selected entity

3) List showing the selected attributes

4) The properties that you can define for the attributes

Tip:

Be careful to select the correct Type when defining property sets from UDAs. For example, if the UDA properties are normal text, select String. If your UDA properties are whole numbers, select Integer. If the wrong Type is selected, the property set export will fail. Note that you can get a string value for a user-defined attribute so that you add the prefix USERDEFINED. to the user-defined attribute, change the Property type to Template attribute and the Type to String.

Example:

Tekla Structures model objects and corresponding IFC entities


Object	IFC
Tekla Structures default objects
Beam	IfcBeam, (IfcMember)
Bolt hole	IfcMechanicalFastener IFC2x3 Steel fabrication view: IfcOpeningElement
Bolts, nuts, and washers	IfcMechanicalFastener
Braces, haunches	IfcBeam, IfcPlate, (IfcMember*)
Column	IfcColumn, (IfcMember), (IfcPile)
Contour plate	IfcPlate
Footings	IfcFooting
Panel	IfcWall
Pour object, pour break	IfcBuildingElementProxy
Rebar end anchor and coupler	IfcMechanicalFastener, (IfcTendonAnchor)
Reinforcing bar	IfcReinforcingBar
Reinforcing mesh	IfcReinforcingMesh
Slab	IfcSlab
Steel assembly/cast unit/pour unit	IfcElementAssembly
Steel/concrete item	IFC2x3: IfcBuildingElementProxy IFC4: IfcDiscreteAccessory
Surface treatment	IfcCovering
Weld	IfcFastener
Common construction objects
Chimney	IfcColumn, IfcBeam, IfcWall, (IfcChimney*)
Pile	IfcColumn, IfcBeam, (IfcPile*)
Purlin, rafter	IfcBeam, IfcColumn, (IfcMember*)
Railing	IfcColumn, IfcBeam, (IfcRailing)
Roof panel	IfcBeam, (IfcRoof*)
Assemblies
Tekla Structures assemblies	IfcFacilityPart (IfcBridgePartTypeEnum)*
Embedded tendon anchor assembly	IfcElementAssembly, (IfcTendonAnchor*)
Floor assembly	IfcElementAssembly, (IfcSlab*)
Railing	IfcElementAssembly, (IfcRailing*)
Ramp	IfcElementAssembly, (IfcRamp*)
Roof	IfcElementAssembly, (IfcRoof*)
Stairs	IfcElementAssembly, (IfcStair*)
Wall assembly	IfcElementAssembly, (IfcWall*)
Rebar assembly	IfcElementAssembly
Assembly sub-part (secondary part)	Exported according to the entity indicated for the corresponding sub-part in this table. To export as IfcDiscreteAccessory, set the advanced option XS_IFC2X3_EXPORT_SECONDARY_AS_DISCRETEACCESSORY to `TRUE` in an .ini file, for example, in teklastructures.ini.

Note:

If the entity is not in parenthesis in the table above, the object is automatically exported as this entity type. If an entity is in parenthesis, the object is not exported as this entity type automatically, but you can select the entity for the object in the IFC export section.
* If an entity in parenthesis is marked with an asterisk (*), it is recommended.
**IfcBridgePartTypeEnum is called IfcBridgePart in the IFC entity list in the property pane.
The IfcBuildingElementPart and IfcBuildingElement entities can also be used. IfcBuildingElement matches beams, columns, etc, but not assemblies.
Polybeams are always exported as B-rep.