Level of Development (LOD) in Building Information Modeling (BIM) refers to a scale that defines the level of detail and accuracy of a BIM model at various stages of its development. It is a critical aspect of BIM that helps project stakeholders understand the degree of completeness and reliability of the information within the model. Different LODs represent different levels of abstraction and information content. The concept of LOD is often associated with the AIA (American Institute of Architects) and the BIM Forum, and it is commonly used in the United States.
Here are the typical LODs and their characteristics:
LOD 100 – Conceptual Design:
- Representation: Generic shapes representing the overall size, shape, and orientation of the building or element.
- Information: Basic information, often minimal and conceptual.
LOD 200 – Schematic Design:
- Representation: More specific and refined shapes indicating the general size, shape, and location of elements.
- Information: Includes approximate quantities, size, shape, and orientation.
LOD 300 – Detailed Design:
- Representation: Defined geometry and specific quantities, sizes, and shapes of elements.
- Information: Accurate and specific information about size, shape, location, and orientation.
LOD 350 – Construction Documentation:
- Representation: Includes specific assemblies, components, and connections with precise geometry.
- Information: Additional information related to fabrication and construction methods.
LOD 400 – Fabrication and Assembly:
- Representation: Model includes fabrication, assembly, and detailing information.
- Information: Accurate and detailed information for fabrication and assembly.
LOD 500 – As-Built:
- Representation: Model reflects the actual physical conditions as constructed.
- Information: Includes precise information about size, shape, location, and orientation, as constructed.
It’s important to note that while the concept of LOD is widely used, there might be variations in its definition and application in different regions or industries. Some organizations or projects might use a slightly modified LOD scale or adapt it to specific needs.
The LOD concept is crucial for effective communication and collaboration in the BIM process. It helps stakeholders understand the reliability of the information within a model at different project stages and ensures that expectations regarding the level of detail are well-defined. Clear definitions of LOD also contribute to the successful execution of BIM projects and the consistent exchange of information among project team members.
