A Model View Definition (MVD) is a subset of the IFC schema chosen for one kind of exchange. IFC as a whole is very large; an MVD says which entities, properties and geometry representations a file must contain for a given purpose, so that the exporting and the importing software can be certified against the same target. When an export dialog asks for "IFC2x3 Coordination View" or "IFC4 Reference View", it is asking which MVD to follow.
At a glance
| Maintained by | buildingSMART International |
| Defines | Which part of IFC an exchange uses, and how |
| Well-known examples | IFC2x3 Coordination View 2.0, IFC4 Reference View, IFC4 Design Transfer View |
| Used for | Software certification and choosing the export setting |
| Comes from | Exchange requirements, often written as an IDM |
What it contains
- Concepts: reusable pieces such as "spatial containment", "property sets for objects" or "body geometry as triangulated surfaces".
- Concept roots: which IFC entities use which concepts (walls, doors, spaces).
- Rules: what must, may or must not be present, such as the geometry types allowed.
- Documentation for implementers, published as mvdXML in older views.
How it is used on projects
Most teams meet MVDs only as an export setting. The choice matters: a Reference View export carries simple, fixed geometry suited to coordination and viewing, while a Design Transfer View aims to carry geometry that can be edited after import. Information requirements should name the IFC version and the view, so that every party exports the same way.
Variations and versions
- IFC2x3 Coordination View was the long-standing default for coordination.
- IFC4 Reference View replaced it for coordination and viewing, with simpler geometry.
- IFC4 Design Transfer View was meant for editable geometry; support in software is limited.
- IFC4.3 extends IFC to infrastructure; buildingSMART has been moving from fixed MVDs towards IDS files that state the requirements of each project.
Common misunderstandings
- "An IFC file is an IFC file." Two exports of the same model in different views can hold different geometry and data.
- "The MVD guarantees the data we need." It covers structure and geometry; project-specific properties still need an IDS or a written requirement.
- "Certification means perfect exchange." Certified software can still be configured to export poorly.
Where to read more
buildingSMART International's technical pages on MVDs and software certification; the IFC versions and IDS entries on this site; your authoring tool's documentation for its IFC export settings.