BIM Forum Fundamental Definitions and connection to AIA LOD - Level of Development (LOD) 100-500

Sep 2, 2026

Defines BIM Forum Level of Development (LOD) standards and explains how each LOD level relates to AIA LOD expectations for modeled building elements. Covers LOD 100 through LOD 500, detailing what can and cannot be reliably derived from the model at each stage, including geometry, orientation, interfaces, and the inclusion of asset information requirements. Highlights progression from generic or database-derived representation to detailed fabrication instructions and Digital Twin capabilities shared and updatable by stakeholders.

LanguageEnglish

CategoryGeneral

FormatDOCX

Pages1

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Fundamental LOD Definitions

LOD 100

LOD 200

LOD 300

LOD 350

LOD 400

LOD 500

BIM Forum Fundamental Definitions and connection to AIA LOD FUNDAMENTAL LOD DEFINITIONS LOD 100 JTCEES: The modeled element is graphically represented in the model with a symbol, derived from a database, or other generic representation. Size, shape and orientation cannot be derived reliably from the model. Some of the agency’s asset information requirements may be included in the element and does not include analysis. LOD 200 JTCEES: The modeled element is graphically represented within the model as a specific system in the XY plane. Size, shape, and orientation can be derived directly from the modeled element in two dimensions with minimal need for plan sheet notes or dimensions. Some of the agency’s asset information requirement are included in the element and may include analysis. LOD 300 JTCEES: The modeled element is graphically represented within the model as a specific system in the XY and Z plane. Size, shape, orientation, and interfaces with other objects can be derived directly from the modeled element without the need for plan sheet notes or dimensions. The agency’s asset information requirements are included for the element and includes analysis to the standard of care for that element. LOD 350 JTCEES: Not included and concept of interfaces and other building systems added to 300. LOD 400 JTCEES: The modeled element is graphically represented within the model as a specific system in the XY and Z plane. Size, shape, orientation, interfaces with other objects, means and methods, and fabrication instructions can be derived directly from the modeled element which includes sub-elements. The agency’s asset information requirements are included for the element. LOD 500 JTCEES: The modeled element is graphically represented within the model as a specific system in the XY and Z plane. Size, shape, orientation, interfaces with other objects, and fabrication instructions can be derived directly from the modeled element. This represents the Digital Twin of the constructed asset. Major transportation asset class attributes are linked to the modeled elements. Modeled objects or assets are useable and updatable by all stakeholders.

FAQs

What does LOD 100 specify for a modeled element in the BIM model?

The element is represented graphically using a symbol, database-derived data, or generic representation. Size, shape, and orientation cannot be reliably derived from the model, though some agency asset information requirements may be included without analysis.

What additional capabilities are introduced at LOD 200 and LOD 300?

LOD 200 allows direct derivation of size, shape, and orientation in the XY plane with minimal need for plan notes or dimensions, and may include analysis. LOD 300 extends to the XY and Z plane, enabling derivation of interfaces with other objects and includes the agency’s asset information requirements with analysis to the standard of care.

How does LOD 500 support the Digital Twin and stakeholder use?

LOD 500 enables direct derivation of interfaces and fabrication instructions, positioning the model as the Digital Twin of the constructed asset. Major transportation asset class attributes are linked to modeled elements, and modeled objects/assets are usable and updatable by all stakeholders.

Sep 2, 2026

Upload by Lucas Vance