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BIM & IFC Glossary — The Terms You Actually Hear on Projects

IFC, BCF, LOD, openBIM, CDE, model checking and more — a practical glossary of the BIM terms that get thrown around on real projects, with the meanings people often leave fuzzy.

3 min read

BIM meetings are full of acronyms and jargon. Nod along without a precise meaning and the misalignment surfaces later. This glossary sorts out the terms you hear most, from a practical angle.

BIM

Method for information-rich building models. Read →

IFC

The common exchange format for BIM (ISO). Read →

BCF

The format for sharing issues. Read →

openBIM

Collaborating through open standards, vendor-neutral.

Formats and standards

BIM (Building Information Modeling) A method and process that treats a building as a collection of meaningful elements carrying properties. See what BIM is.

IFC (Industry Foundation Classes) The vendor-neutral exchange format for BIM, standardised internationally as ISO 16739. Carries geometry, properties and relationships. See what IFC is.

IFC2x3 / IFC4 / IFC4.3 Generations of IFC. IFC2x3 is the long-standing de-facto standard, IFC4 the successor, IFC4.3 the newest generation that adds infrastructure (bridges, roads, rail).

BCF (BIM Collaboration Format) An open format for sharing issues against a model, separate from the model itself, with a camera viewpoint and target elements attached. See what BCF is.

openBIM The philosophy of collaborating through open standards like IFC and BCF, independent of any one vendor. Promoted by buildingSMART.

STEP / ISO 10303-21 The text format underlying IFC files. A valid IFC file begins with ISO-10303-21;.

Design and quality terms

LOD (Level of Development / Level of Detail) A measure of how developed a model is — both geometric detail (Detail) and the reliability of the information (Development). The required LOD shifts by project phase.

Properties / attributes Data attached to an element (material, dimensions, fire rating, manufacturer). The actual content of BIM’s “information.”

Property set (Pset) A named group of related properties. IFC defines standard Psets, and you can also define custom ones.

Model checking / validation Verifying that a model meets requirements — checking mechanically for missing required properties, out-of-range values, naming-rule violations and the like.

Clash detection Overlaying models from multiple disciplines to find physical collisions between elements (e.g. MEP against structure).

Collaboration and operations terms

CDE (Common Data Environment) A single place to manage and share project information, making clear which version is current so everyone references the same data.

Issue A problem or comment on the model — tracked by who raised what, where, and how it was resolved. BCF is the format that carries issues.

Viewpoint A saved camera position and orientation from the moment an issue was raised, so the recipient can open the model from the same angle.

Round-trip Exporting from one tool to IFC, importing into another, and writing it back. Perfect restoration isn’t possible, so use it knowing the limits.

Worksharing A mechanism within a single BIM application for several people to edit the same model simultaneously by division. Distinct from cross-tool exchange via IFC.

Acronyms at a glance

AcronymFull nameIn short
BIMBuilding Information ModelingMethod for information-rich building models
IFCIndustry Foundation ClassesThe common exchange format for BIM
BCFBIM Collaboration FormatThe format for sharing issues
LODLevel of Development/DetailHow developed a model is
CDECommon Data EnvironmentShared environment for project info
PsetProperty SetA group of properties

Agreeing on what the terms mean cuts down the “we were using the same word for different things” accidents in meetings. If a term caught your eye, the linked deep-dive articles go further.

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