IFC Export in Archicad 29: Choosing the Right Translator and Data Settings

Graphisoft’s Archicad 29 help documentation explains that an IFC Translator determines the rules used to convert the model during IFC export. Choosing a file format alone is therefore not enough to produce the right output: you also need to consider the purpose of the exchange, the receiving application and, where required, the Model View Definition (MVD). The steps below outline the core workflow, from selecting a translator and defining the data scope to performing a final check.

1. Define the purpose and method of the exchange

1. Establish what the IFC file will be used for and which application will open it. According to Graphisoft’s documentation, the required data can vary depending on the IFC use case and the application that will open or edit the file. For example, cost estimation, facility management and energy analysis may use different data.

2. To export the model to a new IFC file, use File > Save as.... To add content to an existing, closed IFC model, use File > Interoperability > IFC > Merge to IFC Model. If you need to publish multiple views using different translators, you can use the Publisher workflow in the Document menu.

3. Whichever method you use, the IFC export translator determines the rules for the exchange. Archicad’s predefined translators are set up for specific import or export purposes; for most users, choosing a suitable preset is a good starting point.

2. Match the translator, schema and MVD

1. Open File > Interoperability > IFC > IFC Translators to view or edit translator settings. Select the appropriate translator from the export group. Import and export translators have different settings and are not interchangeable.

2. If an organizational or project delivery standard specifies an IFC schema, select it in the export translator. Archicad 29 documentation lists IFC2x3, IFC4 and IFC4.3 as supported schemas.

3. If the standard requires compliance with a specific MVD, select that as well. An MVD can be thought of as a framework that describes what content is expected in a particular model exchange and what should be left out. The available MVDs depend on the selected schema.

4. After selecting an MVD, some changes to translator settings may break compliance. In that case, Archicad marks the translator as invalid and displays a warning identifying the problematic setting. You can adjust the settings to restore compatibility or use the Override Settings option in the relevant window. Before clicking it, check that the current values match the project standard.

3. Set the file format, translator and element scope

1. When creating a new file with Save as, select the required IFC format from the file type list. To merge content, start the Merge to IFC Model command; only IFC file types can be used for this operation.

2. Enter a file name or select an existing IFC model to merge into. Then choose the export translator from the drop-down list. The Options button opens the IFC Save Options window, which summarizes the selected translator’s settings.

3. If needed, narrow the element scope using the Elements to Export drop-down and/or the Model Filter window. This lets you exclude model content that is not required for the delivery.

4. Finally, start the operation by clicking Save (to export to a new file) or Open (to add content to an existing IFC model).

Pay particular attention to how the Merge to IFC Model command works: existing IFC content is preserved and new content is added; elements are not overwritten. When an element with the same GlobalId is merged, it receives a new IFC GlobalId. This means the command is not suitable for applying changes from one version of an IFC file to another.

4. Choose which data to export

The translator’s Data Conversion preset determines what information, in addition to geometry, is sent to IFC. In the File > Interoperability > IFC > IFC Translators window, select an export translator and open the relevant preset. Assess the options based on the data types the receiving application can read.

• Classifications exports Archicad classifications as IFC Classification Reference data. Element Properties exports Archicad properties in IFC Properties format; you can choose all properties or visible properties. However, the visible properties option is meaningful only if an add-on that manages property visibility in Archicad is installed. Without such an add-on, all properties are exported in either case.

• Building Material Properties and Classifications exports building material properties and classifications. This data is associated with exported elements in IFC 2x3, and with IFC Materials in IFC4 or IFC4.3.

• Element Parameters and Component Parameters can export suitable parameters as IFC quantities or properties. Selecting all parameters can significantly increase file size. The documentation recommends against exporting these parameters indiscriminately if you do not know whether the target application will read them.

• IFC Base Quantities exports basic quantities such as dimensions, area and volume that may be used for quantity takeoffs and cost estimation. IFC Space Containment exports the relationship between zones and suitable objects within them; IFC Space Boundaries exports zone geometry and boundary relationships. The latter can be used in energy and thermal analysis workflows.

Impact on architecture and visualization workflows

For architects and interior designers, the right translator helps prepare the delivered model to meet project standards and the needs of the receiving discipline. Since facility management, cost estimation and energy analysis do not require the same data, using the same properties and parameters for every IFC delivery may not be the right approach. Visualization teams can also limit interdisciplinary model exchanges to the required elements and data that the receiving application will use.

If there is a delivery standard, check schema and MVD compliance. Before exporting a broad set of parameters, consider the impact on file size. Open the final file in an IFC viewer or re-import it into Archicad to check it. This validation, recommended by Graphisoft, helps verify not only that the export completed but also that the model contains the expected content.

Common mistakes

• Using an import translator for export: the two groups contain different settings.

• Selecting a schema or MVD without checking project requirements: MVD options depend on the schema, and changes to settings may trigger a compatibility warning.

• Exporting all parameters by default: if the receiving application cannot read them, the file may become unnecessarily large.

• Treating Merge to IFC Model as a version-update tool: merging adds content; it does not replace existing elements.

• Delivering an IFC file without checking it: validate the export in an IFC viewer or Archicad.