I. INTRODUCTION:

    1. What is Level of Development (LOD)?

      - Level of development (LOD) is a set of specifications that gives professionals in the AEC industry the power to document, articulate and specify the content of BIM effectively and clearly. Serving as an industry standard, LOD defines the development stages of different systems in BIM

     - The LOD specification helps designers define the inherent characteristics of the elements in a model at different stages of development. The clarity in illustration gives depth to a model, signifying how much and at which level someone should rely on a model’s element.

     - Using LOD, designers and engineers can communicate with other professionals. LOD specifications were designed to standardize the use of the LOD framework and use it as an efficient and collaborative communication tool.

   2. Level of Development vs Level of Detail

     - LOD is usually interpreted as a Level of Detail instead of Level of Development. This specification uses the concept of Level of Development. There are important differences.

     - Level of Detail is actually what proportion detail is enclosed within the model element. Level of Development is the degree to which the components’ specification, geometry, and attached information have been thought through – the degree to which project team members may depend on the information when using the model. In essence, the Level of Detail can be thought of as input to the element, while the Level of Development is a reliable output.

II. DEGREES OF COMPLETION AND MODEL CONTENT _ LOD 100 & 200

    1. What is LOD 100?

    LOD 100 elements are not geometric representations. Examples are information attached to other model elements or symbols showing the existence of a component but not its shape, size, or precise location. Any information derived from LOD 100 elements must be considered approximate.

    2. What is LOD 200?

    The Model Element is graphically represented within the Model as a generic system, object, or assembly with approximate quantities, size, shape, location, and orientation. Non-graphic information may also be attached to the Model Element.