IFC Files for Manufacturing: Why Model Quality Determines Data Usability
IFC (Industry Foundation Classes) promises interoperability between different BIM applications. In theory, you can take an IFC file from any source and extract useful data for manufacturing, procurement, or ERP systems. In practice, the quality of what comes out depends entirely on what went in.
If you work with IFC files for downstream data extraction, understanding what affects IFC quality will save you significant frustration and rework.
What IFC Is and Is Not
IFC is an open, neutral file format for exchanging BIM data. It can represent geometry and properties for building elements across different software platforms. However, IFC is a container format, not a guarantee of quality or completeness.
An IFC file can be technically valid while being practically useless. It might contain 3D geometry with no useful properties attached. Or it might have properties with inconsistent naming that makes them impossible to process automatically. The format allows for this variability by design.
The Export Problem
When a BIM application exports to IFC, it makes choices about how to represent model data in IFC terms. These choices significantly affect downstream usability.
Property Mapping
Each BIM application has its own internal data structure. When exporting to IFC, properties need to be mapped to IFC property sets. This mapping might be default (using standard IFC property sets), custom (creating application-specific property sets), or missing (properties that do not get exported at all).
If the source application maps a critical property to a non-standard property set, receiving applications might not know where to find it. The data is technically in the file, but effectively invisible.
Geometry Quality
IFC supports multiple geometry representations. The same object might be exported as:
- Extruded profiles: Simple and clean, preserving parametric information.
- Boundary representation (BREP): More complex surfaces that can represent any shape.
- Tessellated geometry: Triangulated meshes that lose parametric information entirely.
For manufacturing data extraction, the geometry representation usually matters less than the property data. But if you need accurate dimensions, some representations are easier to work with than others.
Classification
IFC uses classification systems to identify what type of thing each element is. An element might be correctly classified as IfcDoor, vaguely classified as IfcBuildingElementProxy, or incorrectly classified altogether. Weak classification makes automated processing difficult.
What Goes Wrong
Here are the most common issues that make IFC files problematic for manufacturing data extraction.
Missing Properties
The most common problem: properties that exist in the source application are not present in the IFC file. This happens when export settings exclude certain property sets, when mappings are not configured, or when the source model simply does not have the data.
You cannot extract what is not there. If your IFC file lacks material specifications, no amount of clever processing will recover them.
Inconsistent Naming
Different projects, different applications, and different users name things differently. One file might have "Width" while another has "width" and a third has "Element_Width". For humans, these are obviously the same. For automated processing, they are completely different properties.
Aggregated Elements
Sometimes elements that should be separate are exported as single objects. A curtain wall system might come out as one massive element rather than separate mullions, transoms, and panels. This makes it impossible to get quantities for individual components.
Placeholder Data
Properties filled with placeholder values like "TBD", "See Spec", or default template values are technically present but practically useless. Automated validation might pass these through, only to cause problems downstream.
How to Get Better IFC Output
If you have control over the IFC export process, several practices improve quality.
Use Model View Definitions
Model View Definitions (MVDs) specify which IFC entities and properties should be included for particular use cases. Using an appropriate MVD helps ensure that relevant data gets exported. Common MVDs include:
- Coordination View: For basic coordination and clash detection.
- Design Transfer View: For fuller model exchange between applications.
- Reference View: For reference models in coordination workflows.
For manufacturing data extraction, you may need to go beyond standard MVDs and configure custom export settings.
Configure Property Set Mapping
Most BIM applications allow you to control which properties export to IFC and how they are organized into property sets. Take time to configure these mappings to include the properties you actually need, with consistent naming.
Validate Before Delivery
Use IFC validation tools to check export quality before sending files to downstream users. Solibri, BIM Collab, and other tools can verify that required properties are present and populated.
Dealing With Poor Quality IFC
Sometimes you receive IFC files and have no control over how they were created. Here are strategies for working with less-than-perfect files.
Property Discovery
Before trying to extract data, explore what is actually in the file. Which property sets exist? What are properties called? This reconnaissance prevents frustration from searching for data that does not exist.
Fuzzy Matching
If property names are inconsistent, consider fuzzy matching approaches that can recognize "width", "Width", and "Element_Width" as the same concept. This adds complexity but improves robustness.
Fallback Strategies
Build workflows that can handle missing data gracefully. If a required property is missing, flag it for manual review rather than failing silently. Provide defaults where appropriate, with clear indication that default values were used.
Feedback Loops
When you find IFC quality issues, communicate them back to the source. Provide specific feedback about what is missing or incorrect. Over time, this improves the quality of files you receive.
IFC Versus Native Formats
A common question is whether to use IFC or native file formats for data extraction. The answer depends on your situation.
When IFC Makes Sense
- Multi-source models: When data comes from different BIM applications.
- Long-term archival: When files need to remain readable for years.
- Standards compliance: When contracts require open format delivery.
- Neutral ground: When no single native format is acceptable to all parties.
When Native Formats Are Better
- Single-source workflows: When all models come from one application.
- Maximum fidelity: When you need every piece of data the application can provide.
- Round-trip editing: When files need to go back to the authoring application.
- Application-specific features: When you need data that IFC cannot represent.
Moving Forward
IFC is a powerful tool for BIM interoperability, but it is not magic. The quality of data you can extract depends on the quality of the IFC file, which depends on how the source model was built and exported.
If you rely on IFC for manufacturing data, invest in understanding what makes a good IFC file and how to produce or request one. The standard is capable of carrying rich data for manufacturing purposes. The challenge is ensuring that capability is actually used.
Want to discuss IFC data extraction for your manufacturing or ERP integration needs? Contact us to explore how we can help improve your data workflows.
Jef Stals
Is passionate about software, technology and innovation in construction and business. With a background in engineering, software and an eye for long-term opportunities, he shares insights on building, strategy, and growth.
