Level of information need

CurrentLOIN

Also: LoIN, Level of definition (historical), LOI (historical)

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.

Explanation

ISO 7817-1:2024 sets out concepts and principles for specifying the level of information need for information deliveries across the asset life cycle. Requirements are defined per purpose, per information delivery milestone, per actor and per object (or object group). Geometric information is typically described through characteristics such as detail, dimensionality, location, appearance and parametric behaviour; alphanumeric information through identification and information content; and documentation through the documents required.

The Exchange information requirements should state the level of information need for each deliverable, and machine-readable specifications such as IDS can express parts of it for automated checking. Unlike numbered scales, the framework does not prescribe fixed levels; each requirement is described explicitly.

Practical example

For door objects at the design-development milestone, the purpose is coordination and door scheduling. Geometry: overall dimensions, swing and position, no hardware detail. Alphanumeric: door number, fire rating, acoustic rating, hardware set reference. Documentation: door schedule. At handover, the purpose changes to maintenance, and the requirement adds manufacturer, product and warranty data, with no further geometry.

Why it matters

It replaces ambiguous labels ("LOD 300") with explicit, purpose-driven requirements, reducing both over-modelling and missing information, and it can be validated.

Common confusion

Not the same as Level of development (a numbered North American scale describing reliability of model elements) or Level of detail (graphical detail only). See the comparison page.

Historical context

The concept appears in ISO 19650-1 (2018). It was detailed in Europe as EN 17412-1 (2020) and then internationalised as ISO 7817-1 (2024). It supersedes earlier UK notions of "level of definition" (level of model detail and level of model information).

Standards and references

  1. ISO 7817-1:2024 — Building information modelling — Level of information need — Part 1: Concepts and principles. ISO, 2024.Original VDC Stack.io wording, based on the standard
    Supports: Concepts and principles for specifying level of information need across the life cycle; published June 2024 · Status: Published June 2024. Adopted in Europe as EN ISO 7817-1:2024.
  2. ISO 19650-1:2018 — Organization and digitization of information about buildings and civil engineering works, including building information modelling (BIM) — Information management using building information modelling — Part 1: Concepts and principles. ISO, 2018. Clause 11 (level of information need).Original VDC Stack.io wording, based on the standard
    Supports: Concept introduced in ISO 19650-1 · Status: Stage 90.92 (to be revised). Revision ISO/DIS 19650-1 at stage 40.93 on 2026-08-18 (decision for new DIS ballot).
  3. BIM Harmonisation Guidelines for Works Departments — Appendix I: ISO 19650 Terminologies (v2). Development Bureau, Government of the Hong Kong SAR.Historical record
    Supports: Level of model definition / LOD / LOI replaced by level of information need

VDC Stack.io writes its own explanations and does not reproduce copyrighted standards text. Consult the cited standard for normative wording.

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VDC Stack.io. (2026). Level of information need. In VDC Stack.io Knowledge Dictionary. Retrieved from https://vdcstack.io/dictionary/level-of-information-need/