SIFCEXPORT

The command SIFCEXPORT exports the networks of the current drawing to the IFC 4x3 ADD2 and IFC 4x0 format

Note: Depending on your version of Navisworks:

• Navisworks 2023: IFC 4x3 format is not supported
• Navisworks 2024: IFC 4x3 format is supported, but not "IFC 4x3_ADD2"
• Navisworks 2025: IFC 4x3_ADD2 format is supported

To use, call SIFCEXPORT from the command line, menu, toolbar or from the Ribbon.

Note: This command is still experimental, so errors may occur

Now that IFC is in version 4x3, many of the elements of the drainage, water and sewage networks are already classified.

In Civil 3D, it was already possible to use the native command IFCEXPORT for export, but it is very limited in recognizing these IFC classes. Even the PipeNetwork was exported as a PROXY element.

Today we have a new extension for Civil 3D, which currently (2024-08-02) runs on versions 2022 to 2024. Learn more here

This extension already recognizes a huge amount of elements and exports them to the correct classes and even allows us to choose the class manually, for example, we draw any solid and want it to represent a manhole. To make this possible, Autodesk's IFC 4x3 extension uses a feature that apparently came from Revit: using a PropertySet that contains a property named "IFC::IfcExportAs", with data in TEXT format, which contains the name of the IFC class we want:

The thing is, IFC classes have a type and a subtype. That's why the manhole class has this "IfcDistributionChamberElement.MANHOLE"

When we see:

• IfcDistributionChamberElement - Manhole element defines a location at which distribution systems and their constituent elements can be inspected or traveled through.
  An IfcDistributionChamberElement is a formed volume used in a distribution system, such as a reservoir, ditch, or manhole.
  Instances of IfcDistributionSystem or IfcDistributionFlowElement can be related to the IfcDistributionChamberElement, allowing their location within or on the chamber to be determined. This is associated with the IfcDistributionChamberElementType
• IfcDistributionChamberElementType - It is used to define a distribution chamber element type specification indicating the product-specific information that is common to all occurrences of that product type.
  The IfcDistributionChamberElementType can be declared within the IfcProject or IfcProjectLibrary using IfcRelDeclares and can be exchanged with or without occurrences of the type.
  Occurrences of IfcDistributionChamberElementType are represented by instances of IfcDistributionChamberElement.
  The IfcDistributionChamberElementType has a PredefinedType property, of type IfcDistributionChamberElementTypeEnum
• IfcDistributionChamberElementTypeEnum - This enumeration identifies different types of distribution chambers:
  • FORMEDDUCT - Space formed in the ground for the passage of pipes, cables, ducts
  • INSPECTIONCHAMBER - Chamber built into a drain, sewer or pipe with a removable cover that allows visible inspection
  • INSPECTIONPIT - Recess or chamber formed to allow access for inspection of substructure and services
  • MANHOLE - Chamber built into a drain, sewer or pipe with a removable cover that allows entry by a person
  • METERCHAMBER - Chamber housing one or more meters
  • SUMP - Recessed or small chamber into which liquid is drained to facilitate its collection for removal
  • TRENCH - Excavated chamber whose length usually exceeds the width
  • VALVECHAMBER - Chamber housing one or more valves
  • USERDEFINED - Type of chamberuser-defined
  • NOTDEFINED - Undefined chamber type

The objective here is not to transcribe the entire specification, but rather to explain how it can be applied to SOLIDOS devices. I suggest watching these videos for a better understanding:

• CLASS 01 - Introduction to openBIM: What is IFC?
• CLASS 02 - Introduction to openBIM: Accessing the buildingSMART documentation

Note that there is a class in which the device fits. Then use the class name to see its type:

• Manhole: IfcDistributionChamberElement
• To define the type, IfcDistributionChamberElementType
• Which has an attribute PredefinedType, which comes from an enumeration IfcDistributionChamberElementTypeEnum that has the values ​​above

Notice the part in bold? Now see what has to appear in the IFC::IfcExportAs PropertySet: IfcDistributionChamberElement.MANHOLE.

The same structure applies to a pipe:

• IfcPipeSegment
• IfcPipeSegmentType
• IfcPipeSegmentTypeEnum

For SOLIDOS to fill the PropertySet, create a property in the modeler, which will contain the name of the class you want the device to have within the IFC file:

In the example I defined it as read-only, since the modeler only models manholes, so I used an Set Property and set the value of IfcExportAs to IfcDistributionChamberElement.MANHOLE

For SOLIDOS to fill the propertyset, you need to associate the IfcExportAs property of the device with the IFC::IfcExportAs property of the PropertySet. Click the button at the top of the screen. Create the property if necessary (see the help for the command SPSETS):

Obviously, it is not just these two properties that you need to link. Each contractor will require a PropertySet. If it asks for those that the IFC requires, for example: Pset_DistributionChamberElementTypeManhole: