BIM Levels of Development (LOD)

LOD 100

Official Definition from the American Institute of Architects

The Model Element may be graphically represented in the Model with a symbol or other generic representation, but does not satisfy the requirements for LOD 200. Information related to the Model Element (e.g., cost per square foot, tonnage of HVAC, etc.) can be derived from other Model Elements.

Practical Interpretation (source: BIM Forum 2023 LOD Specification)

LOD 100 elements are not necessarily geometric representations. Examples are information attached to other model elements: symbols showing the existence of a component but not its shape, size, or precise location; or space reservation volumes. In essence, if information about an element can be derived from the model but the element is not at LOD 200 it is said to be at LOD 100. Any information derived from LOD 100 elements must be considered approximate.

LOD 200

Official Definition from the American Institute of Architects

The Model Element is generically and graphically represented within the Model with approximate quantity, size, shape, location, and orientation.

Practical Interpretation (source: BIM Forum 2023 LOD Specification)

LOD 200 elements are generic placeholders but are recognizable as the components they represent (e.g. a pump, a light fixture, a beam, etc.). Any information derived from LOD 200 elements must be considered approximate.

LOD 300

Official Definition from the American Institute of Architects

The Model Element, as designed, is graphically represented within the Model such that its quantity, size, shape, location, and orientation can be measured.

Practical Interpretation (source: BIM Forum 2023 LOD Specification)

LOD 300 elements are sufficiently developed to fully convey the design intent for the represented item. Note that while neither the LOD definitions nor this Specification specify who models the element, designers rarely generate model elements higher than 300.

LOD 350

Official Definition from the American Institute of Architects

The Model Element, as designed, is graphically represented within the Model such that its quantity, size, shape, location, orientation, and interfaces with adjacent or dependent Model Elements can be measured.

Practical Interpretation (source: BIM Forum 2023 LOD Specification)

LOD 350 is intended to define requirements for model elements that are sufficiently developed to support construction-level coordination. This LOD usually requires craft knowledge, thus the caveat in the LOD 300 interpretation above that designers rarely generate elements at LODs higher than 300. It should be remembered, though, that neither the LOD definitions nor this Specification specify who models the element – if a design team has craft knowledge available, they might choose to develop elements to LOD 350 or higher.

LOD 400

Official Definition from the American Institute of Architects

The Model Element is graphically represented within the Model with detail sufficient for fabrication, assembly, and installation.

Practical Interpretation (source: BIM Forum 2023 LOD Specification)

Essentially LOD 400 describes a model element developed to the level of shop drawings – in most cases, if a project’s specifications call for shop drawings of an item, the project team might model the item at LOD 400. Thus, most models contain few LOD 400 elements.

LOD 500

Official Definition from the American Institute of Architects

The Model Element is a graphic representation of an existing or as-constructed condition developed through a combination of observation, field verification, or interpolation. The level of accuracy shall be noted or attached to the Model Element.

Practical Interpretation (source: BIM Forum 2023 LOD Specification)

LOD 500 does not indicate a higher level than LOD 400, rather it indicates that the element’s geometry is determined through observation of an existing item rather than design of a future item.