IFC describes and exchanges information about a built asset. IDS expresses information requirements that can be checked against an IFC model. In a delivery workflow, IFC carries the model information and IDS provides a structured statement of selected expectations for that information. IFC introduction, IDS user manual
What does each one contain?
| Question | IFC | IDS |
|---|---|---|
| Main role | Represent and exchange model information | Express information requirements |
| Typical content | Objects, attributes, properties and relationships, including representations of geometry | Specifications identifying relevant objects and expected information |
| Typical project use | Deliver information produced by the model author | Communicate and check agreed information expectations |
| Example | A model containing walls and their recorded information | A specification asking for an agreed property on the relevant walls |
IFC supports a wide range of information about buildings and infrastructure. The existence of a field in the IFC schema does not by itself tell your team which project information to request. That decision needs a delivery purpose. buildingSMART's IFC overview
A delivery example
Imagine a project team preparing an IFC model for a design review. The reviewer wants an agreed project reference recorded for a defined group of spaces.
First, the team agrees how the spaces will be identified and where the reference will be recorded. It then expresses the relevant information rule in an IDS specification. The model author prepares the delivery, and the receiving team uses compatible software to check the IFC against the issued specification.
If a reference is missing, the reviewer has a specific issue to investigate. If the wrong spaces were selected, the team needs to revisit the scope before relying on the result.
Does a valid IFC model meet every project requirement?
An IFC schema check and a project information check answer different questions. A delivery needs to be usable as IFC data, and it also needs the information required for its intended purpose.
For a pilot, record those acceptance questions separately. One reviewer might investigate a model-reading error while another investigates a missing project field. Keeping the questions clear helps the team find the correct remedy.
How should the team manage the files?
Agree the IFC version and the IDS support needed before exchange. Give the model issue and the requirement release clear identities, and retain the relationship between them when recording a check.
Start with a small set of information that the team can inspect manually. Expand once the delivery and review workflow is understood.
Read how to create an IDS file and how to review validation results, or explore the IDS editor.