Export in IFC format

Tekla Structures
2022
Tekla Structures

Export in IFC format

You can export Tekla Structures model or a part of the model in the IFC format.

Before you start the export:

  • Define the IFC entities for Tekla Structures model objects. See below for instructions.
  • Define the needed property sets.
  • If you export the IFC file using the base point, define the base point.
  • To have pour objects and pour units (from Tekla Structures 2018 onwards) in your model, set XS_ENABLE_POUR_MANAGEMENT to TRUE. In the IFC2x3 export, to export pour objects instead of CIP concrete parts select the Pour objects check box. In IFC4 export, to export pour objects and pour units instead of cast-in-place parts and cast-in-place pcast units, select the Pours check box. Note that pour unit export is not supported in IFC2x3.

  • IFC2x3 export: You can control how bars created by rebar sets are exported with the advanced option XS_EXPORT_IFC_REBARSET_INDIVIDUAL_BARS. If the advanced option is set to FALSE, bars are exported in groups. If the advanced option is set to TRUE, bars are exported as individual bars. The default value is FALSE.

    Note:

    In the IFC file 'Total number' always shows 1 for groups created by rebar sets, and 'Total weight' and 'Weight' show one bar weight. Use the NUMBER_OF_BARS_IN_GROUP and WEIGHT_TOTAL_IN_GROUP attributes to export the values of the group to the IFC file.

  • IFC2x3 export: You can export B-rep objects as exact solids by setting the advanced option XS_EXPORT_BREP_AS_EXACT_SOLID to TRUE. The default value is FALSE.

    Note that if you export B-reps as exact solids, the IFC file size increases, and the export takes more time.

    To get smooth edges to the export, you may need to set the advanced option XS_CS_CHAMFER_DIVIDE_ANGLE to 10.

  • During the IFC export you can add classification information to assemblies by entering the name of the classification system in the user-defined attributes in Project properties. The classification system is written to the IFCCLASSIFICATION field in the export file. You can define the classification values for the assemblies in Organizer or in the UDA dialog box of the assemblies. Note that classification information is written to the assembly level only.

    For more information about how to add classification information to assemblies in Organizer, see How to add classification code to objects in Organizer and export it to IFC.

    For more information about adding UDAs to the UDA dialog box, see Define and update user-defined attributes (UDAs).

  • You may want to check and modify the user-defined attributes of the exported parts related to IFC export and structural information.

Define IFC entities for Tekla Structures model objects

Before you export Tekla Structures model objects to IFC, you can define the resulting IFC entities for the exported model objects in the object properties.

  1. Double-click an object, for example a column, to open part properties, and click the User-defined attributes button.
  2. On the Structural information tab, set Load bearing to Bearing, if you want to define the user-defined attribute LOAD_BEARING for the exported object.

    Set this option to No for all non-load bearing objects. Bearing is the default value.

  3. Go to the IFC export tab, and in the IFC export type list, select Auto or B-rep:
    • The Auto option will automatically select what kind of Swept Solid IFC object a Tekla object becomes in the IFC.
    • If Auto fails for some reason (such as with a deformation), the export reverts to B-rep automatically, and creates a mesh-based IFC object with less intelligence. These objects are data heavy but still geometrically correct.
    • B-rep will force the IFC object to be always mesh based.
  4. Click Modify in the user-defined attributes dialog box.
  5. In the IFC export section in the property pane, select an option in the IFC entity list to define the IFC entity for the exported model object.

    Below is a list of entities available for a different types of objects:

    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.
  6. You can define the IFC entity more precisely by selecting an entity subtype among the predefined subtypes available in the Subtype (IFC4) list, or select USERDEFINED and then type the desired type in free text in User-defined type (IFC4).

    Note that the subtype and the user-defined type are only supported in the IFC4 export.

    The available subtypes depend on the selected IFC entity.

    For example, if you have a native assembly in your Tekla Structures model, you can define that its entity type is IfcBridgePart, and select a Subtype among the predefined subtypes available, for example, PIER, or select USERDEFINED and then type the desired type in free text, for example, bridge part.

  7. Click Modify in the property pane.

Export in IFC2x3 format

  1. Select the model objects to export.

    If you want to export all model objects, you do not have to select anything.

  2. On the File menu, click Export > IFC.
  3. Browse to the Output file location and replace the name out with the desired file name.

    IFC files are by default exported to the \IFC folder under the model folder. The length of the file path is limited to 247 characters. You do not need to enter the file name extension, it will be automatically added according to the selected File format.

  4. Define the export settings:
    Setting Description

    Parameters tab

    File format

    The options are IFC, IFC XML, zipped IFC, and zipped IFC XML.

    Export type

    Which export type to select?

    • The certified Coordination view 2.0 should be your default.
    • If the model is used only for viewing purposes, or as a reference model, Surface geometry is your choice.
    • Coordination view 1.0 is for those who need to export openings as separate objects.
    • Steel fabrication view is for the fabrication workflow, and to be provided for manufacturing.

    Surface geometry is ideal when the need is to view the model without any need for re-using or editing:

    • Reinforcing bars are exported as B-rep.

    • Export does not support CSG (Constructive Solid Geometry).

    • Curved elements are exported as B-rep.

    • Bolts are exported as B-rep.

    The certified Coordination view 2.0 is recommended to be used when the geometry needs to be edited and modified in the receiving application:

    • Reinforcing bars are exported as extrusions.

    • Export uses CSG (Constructive Solid Geometry) for presenting cuts and voids.

    • Curved elements are exported as extrusions.

    • Bolts are exported as B-rep.

    Steel fabrication view is recommended for exporting detailed information on steel objects for steel fabrication:

    • Exports assembly presentation and dedicated property sets.

    • Bolt holes are exported as voids.

    • Steel fabrication model view configuration file for property sets and properties (IfcPropertySetConfigurations_AISC.xml) is included in the installation by default.

    Coordination view 1.0 is recommended to be used instead of Coordination view 2.0 when you need to have voids and openings presented by using opening elements:

    • Reinforcing bars are exported as extrusions.
    • Voids and openings are exported as opening elements (ifcOpeningElements).
    • Curved elements are exported as extrusions.
    • Bolts are exported as B-rep.

    Additional property sets

    • To define a new property set, select <new> and click Edit.

    • To use an additional property set created earlier, select the property set from the Additional property sets list.

    • To edit an existing property set, select the property set from the list and click Edit.

    Location by

    Model origin exports the model relative to 0,0,0.

    Work plane exports the model Elevation relative to the current work plane coordinate system.

    Base point: <name of base point> exports the model relative to the base point using coordinate system values East coordinate, North coordinate, Elevation, Angle to North, Latitude and Longitude from the base point definition. The base point latitude and longitude values have a microsecond accuracy. Note that if the base point has not been defined, it is not displayed in the list.

    Advanced tab

    Object types

    Select the object types to export. The options are:

    Assemblies

    Bolts

    Welds

    Pour objects

    Grid

    Reinforcing bars

    Surface treatments and surfaces

    If you select Assemblies, you can exclude single part assemblies by selecting Exclude single part assemblies in the Other area.

    To export pour objects instead of CIP concrete parts select the Pour objects check box.

    Note that edge chamfers are omitted from the exported IFC model. This is to enable better interoperability with plant design systems. If the geometry with edge chamfers is needed, you can set the IFC export type to B-rep separately for those objects in the object user-defined attributes dialog box on the IFC export tab.

    Property sets

    Selecting the option Base quantities adds in the exported IFC file a Quantity takeoff add-on view containing additional information on the entities in the exported IFC model.

    For more information about the base quantities, see IFC base quantities in exported IFC model.

    Select one of the following options for Property sets:

    • Default exports the default set of properties.

    • Minimum exports the minimum set of properties required by the buildingSMART IFC standard. To view the property sets, click View.

    • If you do not want to export predefined property sets, leave the box empty. If you do this, the View button is not available.

    Other

    Layer names as part names uses part names, such as COLUMN and BEAM, as layer names for exported objects. If this option is not selected, then layer name will be the object's phase number followed by the phase name.

    Export flat wide beams as plates exports flat and wide beams as plates. Select this option if you have modeled plates as beams or columns with flat profiles. For example, some system components use beams or columns instead of plates.

    Use current view colors exports the objects using the colors defined in object representation, not the class colors. Note that exporting object transparency settings is not supported.

    Select Exclude single part assemblies when you export assemblies.

    Spatial hierarchy from Organizer uses the spatial hierarchy ( Building-Site-Section-Floors) created in Organizer in export.

    Do the following:

    1. Select Spatial hierarchy from Organizer.

    2. Create a project hierarchy in Organizer.

    3. In Organizer, right-click the project, and select Use for reporting.

    4. Before the IFC export, synchronize or write the Organizer data in the Tekla Structures model by right-clicking the project in Organizer, and selecting Write to the model for reporting.

      If you do not select Spatial hierarchy from Organizer, the export uses the IFC export hierarchy defined in project property UDAs.

  5. Select either Selected objects or All objects to define the object selection for the export. If you selected Selected objects, you need to select the objects.
  6. Click Export.

Export in IFC4 format

You can export a Tekla Structures model or a part of the model in the IFC4 format.

  1. Select the model objects to export.

    If you want to export all model objects, you do not have to select any objects.

  2. On the File menu, click Export > IFC4.
  3. In the File name box, enter the file name without a file name extension.

    The extension will be automatically added according to the selected Format. The length is not limited.

  4. Browse for the Folder location.

    IFC files are by default exported to the \IFC folder under the current model folder.

    Both absolute and relative paths can be defined.

  5. In Selection, select whether you want to export All objects or Selected objects.
    Note that if you choose Selected objects, you need to select Spatial hierarchy from Organizer.
  6. Define other export settings:
    Setting Description

    Location by

    Model origin exports the model relative to 0,0,0.

    Work plane exports the model relative to the current work plane coordinate system.

    Base point: <name of base point> exports the model relative to the base point using coordinate system values East coordinate, North coordinate, Elevation, Angle to North, Latitude and Longitude from the base point definition.

    Object color

    Select whether you want to export objects using object class colors or object group colors. If you select object group colors, the defined transparency settings are also exported.

    Layer names as

    You can use phases, part names, or template attributes as layer names for exported objects. Select Name or Phase from the list, or type the attribute name in the box.

    Note that you cannot use user-defined attributes as the layer name.

    Format The options are IFC and zipped IFC.

    Export type

    The Reference view option is intended to support the referencing workflow, and exported files can be used as reference files, and viewed in a viewer. The Reference view is not meant to be used for conversion to native objects.

    The overall goal of the Reference view is to provide workflows for various software applications that do not require modifying geometry. Such applications enable viewing, estimating, building, operating, and other downstream analysis.

    Design transfer view is intended for the handover workflow, meaning import for further editing. This requires the conversion of the IFC entities into native objects. One example is the takeover of the structural engineering model (or part of it) into the basis of the structural detail modeling . The IFC object conversion will be used to convert the IFC entities to Tekla Structures native objects. Typically import and conversion are only needed a couple of times, or even once only. The result may require some rework to accomplish a proper model.

    Bridge view: The main purpose of the Bridge view export is to extend Tekla Structures to bridge constructions. The bridge IFC files are based on the IFC4.3 schema.

    IFC4precast view supports the fabrication data transfer workflow of precast elements. At this phase it covers the fabrication of precast walls and slabs including all the needed reinforcement and embeds.

    For more information about IFC4precast, see IFC4precast.

    Additional property sets

    • To define a new property set, select <new> and click Edit.

    • To use an additional property set created earlier, select the property set from the Additional property sets list.

    • The additional property sets are stored in the \AdditionalPSet folder under the model folder.

    Cast-in-place export

    Allows you to select more precisely what to include in the cast-in-place export. The options are Pour units or pour objects and CIP cast units or parts.

    Export flat wide beams as plates

    Select this option if you want to export flat and wide beams as plates. Select this option if you have modeled plates as beams or columns with flat profiles. For example, some system components use beams or columns instead of plates.

    Spatial hierarchy from Organizer

    Spatial hierarchy from Organizer uses the spatial hierarchy ( Building-Site-Section-Floors) created in Organizer in export.

    Do the following:

    1. Select Spatial hierarchy from Organizer.

    2. Create a project hierarchy in Organizer.

    3. In Organizer, right-click the project, and select Use for reporting.

    4. Before the IFC export, synchronize or write the Organizer data in the Tekla Structures model by right-clicking the project in Organizer, and selecting Write to the model for reporting.

    Note that the selected objects are only exported when Spatial hierarchy from Organizer has been selected.

    If you do not select Spatial hierarchy from Organizer, the export uses the IFC export hierarchy defined in project property UDAs.

    Also note that in bridge models the export always uses the hierarchy defined in project property UDAs.

    Object types

    Select the object types to export among the listed types.

    Note that edge chamfers are omitted from the exported IFC model. This is to enable better interoperability with plant design systems. If the geometry with edge chamfers is needed, you can set the IFC export type to B-rep separately for those objects in the object user-defined attributes dialog box on the IFC export tab.

  7. Click Export.

After a successful export, a message box is displayed. In this message box you can open the folder where the exported IFC model is stored, or view the log file in a browser. The log file gives detailed information of the export process, exported entities and the errors occurred during the export.

Limitations in IFC4 export

  • The IFC4 export always contains the full assembly. If the part IFC entity is set None in the part properties, the part and its bolts are not included in the export.
  • The user interface does not provide all the features included in the IFC2x3 export user interface.
  • The Reference view is intended to be used for design coordination and for referencing workflow.
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