LOD (Level of Development) in the context of Building Information Modeling (BIM) refers to a reference system used to specify the reliability and completeness of information within a BIM model at different stages of a construction project. It defines the level of detail and accuracy of the BIM elements and their associated data. LOD helps stakeholders understand the reliability of the information contained within the model, facilitating effective communication and decision-making throughout the project lifecycle.
The specific definitions of LOD levels may vary slightly depending on the industry or organization, but generally, they follow a similar concept.
Here is a breakdown of LOD levels commonly used in the industry:
LOD 100: Conceptual/Schematic Design Stage - Represents basic massing, size, shape, and location of elements. It provides a rough representation with limited detail and accuracy.
LOD 200: Design Development Stage - Specifies elements with more detail, such as approximate sizes, shapes, and locations. It includes generic components and basic system representations.
LOD 300: Construction Documentation Stage - Provides specific and accurate elements that are modeled as individual components. It includes manufacturer-specific details and may incorporate some fabrication, assembly, or construction information.
LOD 350: Construction Stage - Represents elements with a high level of accuracy, including precise size, shape, location, quantity, and orientation. It includes connections, fabrication, and construction details suitable for construction purposes.
LOD 400: Fabrication/Assembly Stage - Focuses on elements prepared for off-site fabrication or assembly. It includes detailed information, such as specific assemblies, connections, and fabrication instructions.
LOD 500: As-Built Stage - Represents the accurate final condition of the constructed or installed elements. It includes detailed information about the actual physical characteristics, performance data, and maintenance requirements.
These LOD levels provide a standardized language for communication and ensure that all project stakeholders have a clear understanding of the level of detail and accuracy associated with the BIM elements at different stages of the project.