Level of Development (LOD) describes how far a model element has been developed — its geometry and the reliability of its information. It is defined for element types, not whole models, in the BIMForum LOD Specification.
The levels
| LOD | Meaning | Typical use |
|---|---|---|
| 100 | Symbol or mass; approximate area/volume | Concept, feasibility |
| 200 | Generic element with approximate size, shape and location | Schematic design |
| 300 | Specific element with accurate size, shape, location and orientation | Design development, coordination, tender drawings |
| 350 | LOD 300 plus interfaces with other systems (supports, connections, clearances) | Detailed coordination, clash resolution |
| 400 | Fabrication-ready detail and assembly information | Shop drawings, fabrication |
| 500 | Field-verified as-built representation | Handover, facility management |
LOD vs LOD vs LOI
“Level of Detail” refers to graphics only; “Level of Development” includes reliability of information. Under ISO 19650, many teams instead specify Level of Information Need (geometry, alphanumeric data and documentation separately).
Choosing the right level
- Don’t ask for LOD 400 everywhere — it multiplies effort. Specify by element and stage.
- MEP coordination usually needs LOD 350 for services and the structure they hang from.
- LOD 500 is only meaningful if someone actually verifies the field condition.
Common mistakes
Treating LOD as a model-wide number, not linking it to a model use, and forgetting to state who is responsible for each element. A clear LOD matrix in the BIM Execution Plan avoids all three.