LOD Specification is a reference meant to empower the AEC Industry’s practitioners to be able to specify and articulate at a high level of clarity the content and reliability of BIMs at stages in the design and construction processes. The LOD Specification uses the basic LOD definitions developed by the AIA for the AIA G202-2013 Building Information Modeling Protocol Form and is organized by CSI Uniformat 2010. It defines and illustrates characteristics of model elements of different building systems at different Levels of Development. This clear articulation allows model authors to define what their models can be relied on for and allows downstream users to clearly understand the usability and the limitations of models they are receiving.

The intent of this Specification is to help explain the LOD framework and standardize its use so that it becomes more useful as a communication tool. It doesn’t determine which Levels of Development shall be achieved at what time during a project but lets the user of this document determine model progression specification. To help to achieve the document’s intent, the most important are its primary objectives: