Level of Development (LOD) in BIM describes the development stages. It is a set of specifications that empowers experts in the AEC industry to efficiently document, communicate, and specify BIM (Building Information Modeling) content. LOD is defined as a standard that specifies how the 3D geometry of a building model can be refined to various levels of refinement and is used to determine the service level required. It reflects how much various members of the team can rely on information related to a specific piece.
The development stages are specifically designed for design, 3D visualization, construction-quality quantities, scheduling, estimations, on-site production control, and fabrication at various phases. The clarity of visualization offers a model depth, indicating how much and at what level a model's element should be relied on.
LOD 100 - Conceptual / Pre-Design
In that LOD, the 3D model of the structure is created to show information at a basic level. Area, height, volume, position, and orientation are all determined parameters.
LOD 200 - Schematic Design
The model element is graphically represented with approximate amounts, size, shape, placement, and orientation in a general model.
LOD 300 - Design Development
The project's origin has been determined, and the model element has been accurately positioned relative to the origin of the project.
The model element is graphically represented in the model as a specific system, object or assembly with information such as quantity, size, shape, placement and orientation. Additionally, non-graphical data can be added.
LOD 350 - Construction Documentation
LOD 350 contains details and model elements that describe how building elements interact with various systems and other building elements, as well as images and written definitions.
LOD 400 - Fabrication & assembly
The element model is represented as specific assemblies, and contains information on fabrication, assembly and details such as exact quantities, sizes, shapes, locations and orientation. Non-geometric data can also be connected to model parts.
LOD 500 - Operational/As-built Models
The element is modeled as formed assemblies for maintenance and operation. Non-geometric information is attached to the modeled elements in addition to the actual and exact size, shape, location, quantity and orientation.