When it comes to LOD 100, 200, 300, and so on, many industry professionals understand what model accuracy means. However, for newcomers entering the field, this concept can be unfamiliar. Today, the BIM Architecture Training Network editor will provide a clear explanation of BIM model accuracy for beginners.
The Level of Detail in a model, often referred to as Level of Development (LOD), describes the progression of a BIM model component from the most basic conceptual stage to the highest level of detail and accuracy. The American Institute of Architects (AIA) introduced the LOD concept in its 2008 document E202 to standardize BIM involvement and define project stages clearly.
LOD is categorized into five stages, representing the process from conceptual design to final construction. To allow for potential future expansion, these levels are numbered from 100 to 500. The specific levels are defined as follows:
100. Conceptual representation
200. Approximate geometry of components (schematic and design development)
300. Precise geometry of components (construction drawings and detailed design)
400. Fabrication and assembly details
500. As-built and project completion
LOD 100 corresponds to conceptual design. At this stage, the model generally consists of building massing that represents the overall form, including factors like volume, orientation, and rough cost per square meter.
LOD 200 matches schematic or preliminary design. The model includes general systems with approximate quantities, sizes, shapes, locations, and orientations. LOD 200 models are often used for system analysis and general performance evaluation.
LOD 300 represents detailed construction drawings. At this level, models are suitable for cost estimation, coordination, clash detection, construction scheduling, and visualization. The model should also contain component properties and parameters as specified by the owner in BIM submission standards.
LOD 400 is suitable for fabrication and installation. These models are typically used by specialized contractors and manufacturers for producing and assembling components such as plumbing, electrical, and HVAC systems.
LOD 500 describes the as-built condition of the project. This final stage model integrates into the building’s operations and maintenance system, serving as a comprehensive database. It includes complete component properties and parameters required by the owner’s BIM specifications.
In practical BIM applications, it is essential to define the appropriate LOD level based on the project phase and its intended purpose. Modeling accuracy should align with the required LOD level. LOD provides a standardized, evidence-based framework for applying BIM. That said, adjustments to LOD can be made to suit specific project needs rather than applying it rigidly.
With this overview, BIM newcomers should now have a better understanding of BIM model accuracy. For more information and resources on BIM, please visit our official website: BIM Architecture Training Website bimii.com.
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