Level of development vs level of information need
Both describe how much information a model element should carry. LOD uses numbered levels from the BIMForum specification; level of information need (ISO 7817-1) describes requirements explicitly by purpose.
| Aspect | Level of development (LOD) | Level of information need |
|---|---|---|
| Origin | AIA contract documents; BIMForum element specification (North America) | ISO 19650-1 concept; detailed in EN 17412-1 and ISO 7817-1:2024 |
| Form | Numbered levels (100, 200, 300, 350, 400; 500 in some contracts) | Explicit requirements per purpose, milestone, actor and object |
| What it describes | How developed and reliable an element is | Geometry, alphanumeric information and documentation needed for a purpose |
| Machine-checkable? | Not directly — levels are described in prose and images | Partly — alphanumeric requirements can be expressed in IDS |
| Typical use | Model element tables in North American BEPs and contracts | EIR under ISO 19650; increasingly international |
The practical takeaway
Many Canadian projects use both: LOD tables from habit and contract templates, and ISO 19650 language from public-sector owners. Whichever you use, say what each deliverable is for.
Full definitions
- Level of development (LOD) — A numbered scale (LOD 100–400, plus 500 in some frameworks) describing how far a model element's geometry and information have been developed — and therefore how much other team members can rely on it.
- Level of information need — A framework for specifying the extent and granularity of information required for a purpose — covering geometry, alphanumeric data and documentation — so that no more and no less is delivered than is needed.
- Level of detail — How much graphical or geometric detail a model element shows. As a project-wide numbered scale it has largely been replaced by level of development and level of information need.
Updated October 14, 2026. Sources are listed on each linked definition.