USING IFCExportAs IN REVIT

Most of the components built in Revit are exported to the correct IFC Class via the text mapping file in the File menu > Export > Options > IFC Options. For example, the Doors category gets mapped to IfcDoor.

However, in some cases you may need use a certain tool in Revit to model something but you know that the tool you have chosen will export to an IFC Class not intended for that component e.g. modelling floor finishes as slabs but you want them to be IFCCovering.
In these cases that is where the parameter IfcExportAs can be used.

SHARED PARAMETER

1. In your shared parameter file create a group called “IFC Properties”.
   
2. Within this group create a new shared parameter called “IfcExportAs”
   
3. Define it as a Text parameter and click OK.

This shared parameter is then available to be used within your families and projects.

COMPONENT FAMILIES

For components it is best to embed the shared parameter within the family, so its Ifc Class override is already configured when it is loaded into a project for use.

An example of this would be with a pile foundation. The default mapping for the Structural Foundations category in Revit is to IfcFooting. But as a pile has its own class IfcPile.

1. Within the family go to the Modify ribbon > Properties panel and click the Family Types
   
   
2. On the Family Types dialog box, click New Parameter.
   
3. Select Shared parameter and browse to the IfcExportAs parameter within your shared parameter file.
4. Set the Group parameter under dropdown to IFC Parameters and click OK.
   
5. In the Family Types dialog box complete the IfcExportAs value for the Ifc Class of the component. In this case “IfcPile”.
   Note: If you have multiple types within the family, ensure this step is completed for all types.
   
6. Click OK.
7. Save and close your family.
8. Load the family into a blank project.
9. Create an instance of the component and export to IFC to test the IfcExportAs is working correctly.
10. Open the IFC in a viewer such as Solibri to confirm this.
    

The family is then ready for use within your projects.

NESTED FAMILIES

It is possible to have different content within one family mapping to different IFC Classes. To achieve this, each part of the family that is to be mapped to its own IFC Class, needs to be a nested family and have the IfcExportAs completed.

SYSTEM FAMILIES

System families need to be treated slightly differently. The IfcExportAs parameter needs to be inserted as a project parameter and its value overridden within the project model itself.

An example of this would be using the Floor tool to create finishes.

The default mapping for the Floor category in Revit is to IfcSlab. But in this case, it needs to be overridden to “IfcCovering”.

1. Click the Manage ribbon > Settings panel and click Project Parameters.
   
2. On the Project Parameters dialog box, Click Add.
   
3. Click Shared parameter and browse to the IfcExportAs parameter within your shared parameter file.

4. Click Type
   
   
5. Group parameter under IFC Parameters
   
   
6. Check All
   Click OK
   

7. Select the system family you want to override and click Edit Type.
8. In the Type Properties dialog box complete the IfcExportAs value for the Ifc Class of the component. In this case “IfcCovering”.
   
9. On the Type Properties dialog box, click OK.
10. Export to IFC to test the IfcExportAs is working correctly.
11. Open the IFC in a viewer such as Solibri to confirm this.
    

Note: Some System Families such as Walls, Ceilings and Roofs are not able to be overridden using the IfcExportAs parameter.