Every model element looks equally authoritative on screen. LOD exists to say which ones actually are. Defined by the AIA and maintained in the BIMForum LOD Specification, the scale tells downstream users how much an element’s geometry and attached information can be trusted — and therefore what decisions it can support.
The levels in practice
- LOD 100 — conceptual. A symbol or massing placeholder; existence, not dimensions.
- LOD 200 — approximate. Generic elements with rough size, shape, and location.
- LOD 300 — precise. Accurate geometry and location; the usual baseline for coordination and clash detection. LOD 350 adds interfaces to other systems, like connections and hangers.
- LOD 400 — fabrication. Detail sufficient to manufacture and install from.
- LOD 500 — as-built. Field-verified geometry and data, the basis for handover and operations.
Frame glossary
The same column at five levels of development
A common misreading is treating LOD as “level of detail” — how much geometry an element has. Development is about reliability, not richness: a highly detailed manufacturer object dropped into a schematic design is visually LOD 400 but contractually LOD 200. Element information can also lag or lead geometry, which is why newer frameworks like ISO 19650’s “level of information need” split the two explicitly.
Why it matters for BIM analytics
LOD sets the error bars on every number you pull from a model. A quantity takeoff from LOD 200 elements is an early estimate; the same query at LOD 350 is something you can procure against. Analytics workflows therefore need to know not just what is in the model but how developed it is.
Because Frame extracts full property data per element and per version, dashboards like the model health template can make development visible: which categories carry complete parameters, where placeholder elements persist, and how information matures across versions as the project moves toward handover.