You may have heard the terms like LOD 100, LOD 300 or even LOD 400 from time to time. What is LOD and the meaning of those numbers? Here are some basics about LOD and constructability for you.


In the world of Building Information Modeling (BIM), LOD stands for Level of Detail or Level of Development. As a common reference in the standards published on the BIMForum, LOD refers to Level of Development, representing the depth of thinking applied to the model, how reliable the model is.


Brief LOD history

Level of Development (LOD) was published by the American Institute of Architects (AIA) in 2009 and then further developed by the American General Contractors (AGC) which has been steadily expanding the definition. The specification of LOD is updated annually on the BIMForum in relevance and usefulness to the AECO industry.


LOD 200, 300, 350 and 400 – What’s the Difference?

The AGC provides an interpretation of the AIA defined Level of Development as follows:

  • LOD 100 - A conceptual model that derives information from other model elements
  • LOD 200 - Schematic layout with approximate size, shape, and location
  • LOD 300 - Modeled as design-specified size, shape, spacing, and location of equipment
  • LOD 350 - Modeled as actual size, shape, spacing. Location and connections of equipment supplied
  • LOD 400 - Supplementary components added to the model required for fabrication and field installation



Constructability defines the ease and efficiency with which structures can be built. The more constructible a structure is, the more economical it will be. To increase the constructability in a construction project, the construction model progresses from a design level LOD 200 to LOD 300, LOD 350 and LOD 400.  


Achieving LOD 400 requires the right skillset, software and access to the right information. The innovative technology of 3D modeling-based Tekla Structures has been utilized in numerous famous projects to reach LOD 400. Let’s have a look at one good example!


In the design of Gangneung Ice Arena, one of main stadiums of 2018 PyeongChang Winter Olympic Games, Tekla Structures played a crucial role in minimizing errors in the entire process from designing complex steel structures to the fabrication and installation, and completing construction within a short period of time.


Tekla Structures is ready to satisfy high LOD for all structural project types, regardless of structural material. With Tekla, structural engineering offices can afford to reduce their risks and add customer value, by minimizing the uncertainty that arises from incomplete and uncoordinated construction documents.


Start learning the powerful BIM tool to master the skill set at!

Reference: The LOD on the LOD, Jim Reis