Level of Development (LOD) communicates how far a model element has been developed and how it may be relied upon. Agree the required uses and deliverables in the project’s BIM requirements.

LOD standard

Level of Development in BIM:

The BIMForum LOD Specification provides element-level guidance and illustrations. Use the specified edition and the project’s agreed modeling requirements together.

LOD concerns the reliability of an element, not simply how realistic a rendering looks. Detailed geometry can still be unsuitable for a particular use if it has not been coordinated or verified.

Different elements in one model may have different development requirements. Avoid describing every element as having a single uniform LOD without checking the agreed scope.

Geometrical detail and associated information should both be defined for the intended deliverable. The expression “LOD = detail + information” is not a universal standard definition.

LOD

ISO 19650-1:2018 addresses concepts and principles for information management using BIM. It should not be cited as the source of the numbered BIMForum LOD categories.

 lod & loi

lod with loi

The following short descriptions summarize the BIMForum framework; consult the specification for individual elements and permitted uses.

LOD 100: Conceptual representations support preliminary understanding; information about the element may be derived from other model elements.

LOD 200: Generic representations communicate approximate quantities, dimensions, form, position, and orientation.

LOD 300 and 350: LOD 300 supports measurement of specified element geometry. LOD 350 additionally represents interfaces with other systems needed for coordination.

LOD 400: Element geometry supports fabrication, assembly, and installation within the agreed scope.

LOD 500: Represents existing or as-constructed conditions with a stated accuracy and verification basis; it is not simply more detailed than LOD 400.

Operational records, manufacturer data, and maintenance information should be specified separately as required deliverables, rather than assumed from a LOD number.

LOD100-500

CAD geometry and BIM information

Visual complexity alone does not establish a reliable BIM deliverable. The project must define geometry, attributes, coordination, verification, and exchange requirements.

A software name alone neither proves compliance with a specified LOD nor imposes a universal LOD 200 limit. Assess the actual element and agreed use.

Choose authoring and coordination tools that can deliver the required information and exchange formats. Review the exported information as well as the source model.

Document the intended uses, responsibilities, and acceptance checks in the project requirements.