IFC IDS: Automating BIM Information Requirements

What Is IDS?

IDS is a buildingSMART standard for defining information that specific objects in an IFC model must provide. A project team can specify which properties, values, classifications, or entity types are required at a particular delivery stage.

IDS does not replace IFC. IFC carries model information, while IDS describes requirements against that information. IDS is also not a complete geometric clash detector or a universal building-code checker; its main focus is structured information requirements.

How an IDS Check Works

1. Define requirements. Identify the objects and information required for delivery.
2. Export the model. Deliver an IFC file from the authoring application.
3. Validate the IFC. An IDS-capable checker tests the model against the requirements.
4. Resolve failures. Correct missing or invalid information and run the check again.

A useful report distinguishes missing properties from values that fail a constraint. This helps teams identify what needs correction and who should address it.

Example: Checking Door Information

Imagine a handover requirement stating that every door must have a fire-rating property. An IDS specification can target relevant door objects and require that property to be present. A stricter rule may constrain its value, provided the rule is supported by the IDS version and validation tool being used.

The property name, property set, data type, and permitted values must match the project's information standard. Inconsistent naming conventions can cause avoidable validation failures.

IDS Compared with Other BIM Checks

• IFC schema validation: checks whether the file follows the IFC data schema.
• IDS checking: checks whether defined information requirements are met.
• Clash detection: identifies spatial conflicts between model elements.
• Building-code checking: evaluates project data and geometry against applicable regulations and usually needs broader logic.

These methods complement one another. A reliable BIM quality process combines the checks required by the project rather than treating one report as proof that the entire model is correct.

Implementation Tips

• Agree on IFC versions, property naming, classifications, and units early.
• Test specifications against a representative IFC sample before formal acceptance.
• Version-control the IDS file alongside project information requirements.
• Confirm that your authoring and checking tools support the required IDS features.

Frequently Asked Questions

Does IDS replace BIM coordination software?

No. IDS focuses on machine-readable information requirements. Coordination tools may still be needed for clash detection, issue management, model viewing, and wider quality assurance.

Can IDS check every property in an IFC file?

The available checks depend on the IDS specification, IFC data structure, and software support. Test the requirements with the toolchain intended for your project.