Mastering the Level of Development (LOD) Specification in BIM: A Guide for Project Teams and BIM Experts

Building Information Modeling (BIM) has revolutionized the way we approach construction projects, providing a more efficient and accurate way to communicate information about a structure or project. One important aspect of BIM is the Level of Development (LOD) Specification, which is a reference tool intended to improve the quality of communication among users of BIMs about the characteristics of elements in models. In this blog post, we will explore the LOD Specification and its role in BIM. For the detailed input we used the BIMForum definitions.

Understanding the LOD Schema

The LOD Specification expands upon the LOD schema developed by the American Institute of Architects (AIA) for its E202-2009 BIM and Digital Data Exhibit and updated for the AIA’s G202-2013 Project BIM Protocol Form by providing definitions and illustrations of BIM elements of different building systems at different stages of their development and use in the design and construction process.

Building Information Modeling presents information about a construction project or structure in the form of three-dimensional graphical representations of elements (e.g., doors, beams, etc.), which can be further associated with information about other characteristics of those elements. It is possible for the graphical representation of an element, taken alone, to suggest that greater accuracy or intention can be attributed to the element than is in fact the case. The AIA’s LOD Schema was developed to provide a more systematic way of conveying the extent of reliance that may be placed on an element. Many participants in the design and construction process felt, however, that the AIA’s brief narrative definitions left too much room for interpretation.

The Creation of the LOD Specification

Discussions within the BIMForum led to the creation by a multi-disciplinary task force of the LOD Specification. The LOD Specification is an organized collection of interpretations of the AIA’s LOD definitions describing input and information requirements and providing graphical examples of the different levels of development of a broad variety of building element classes.

Users of the LOD Specification are cautioned that the LOD Specification does not prescribe the necessary levels of development for different steps in the construction process. That determination is left to each project team. It is believed, however, that the availability of more precise definitions will reduce the risks of miscommunication among members of project teams when the expectations for different stages in the design and construction process are established, through easier identification of what each member of the team is expected to deliver and greater predictability of the level of effort that is required to create each member’s deliverables.

In this blog post, we dive deeper into the specific application of LOD in stair construction and its importance for ensuring safety and functionality. Click here to learn more about LOD and its significance in stair construction.

Organization of the LOD Specification

The LOD Specification is organized by CSI Uniformat 2010, with the subclasses expanded to Level 4 (and in a few cases to Level 5) to provide detail and clarity to the element definitions. The LOD Specification addresses only LOD 100 through LOD 400 of the AIA’s LOD Schema, along with a new level – LOD 350 – which was added between LOD 300 and LOD 400 to better address the information levels required for effective trade coordination. The LOD Specification does not address LOD 500 since that LOD relates to field verification and is not an indication of progression to a higher level of geometry or information.

Interpretation of the LOD Definitions

The BIMForum’s interpretation of the LOD definitions are as follows:

• LOD 100 elements are not geometric presentations. They may be symbols or other generic representations of information that can be derived from other model elements. Any information derived from LOD 100 elements must be considered approximate.
• LOD 200 elements are represented graphically but are genericplaceholders, e.g., volume, quantity, location, or orientation. Any information derived from LOD 200 elements must be considered approximate.
• LOD 300 elements are graphically represented as specific systems, objects, or assemblies from which quantity, shape, size, location, and orientation can be measured directly, without having to refer to non-modeled information such as notes or dimension call-outs.
• LOD 350 elements are enhanced beyond LOD 300 by the addition of information regarding interfaces with other building systems. For example, an LOD 350 masonry wall would include information about the wall's interface with the roof, floor, and other building systems.
• LOD 400 elements are the most detailed level, providing complete information about the elements, including materials, fabrication, assembly, and installation information.

Benefits of the LOD Specification

The LOD Specification provides a clear and consistent way of communicating the level of detail and accuracy of information in a BIM model. By using the LOD Specification, project teams can ensure that they are all on the same page when it comes to the level of detail and accuracy of information that is expected at different stages of the project. This can help to reduce the risk of miscommunication and misunderstandings, leading to a smoother and more efficient construction process.

Furthermore, the LOD Specification can also help to improve the accuracy and quality of BIM models, as it provides clear guidelines for what information is expected at each level of development. This can help to ensure that the BIM model is as accurate and complete as possible, which can ultimately lead to a more successful project.

Conclusion

In conclusion, the Level of Development (LOD) Specification is an important tool for improving the quality of communication among users of Building Information Models (BIMs). By providing clear definitions and illustrations of BIM elements at different stages of development, the LOD Specification can help to ensure that project teams are all on the same page when it comes to the level of detail and accuracy of information that is expected in a BIM model. This can lead to a smoother and more efficient construction process, as well as a more accurate and complete BIM model. As a BIM expert, it is essential to understand and utilize the LOD Specification to ensure the success of your projects.

The BIM Engineers are a team of experts who specialize in designing and modeling buildings using Building Information Modeling (BIM) technology. We are skilled in utilizing the Level of Development (LOD) Specification to ensure that the BIM models they create are accurate and complete at all stages of the design and construction process. As a service, they can provide detailed and precise BIM models at all LOD's, from LOD 100 to LOD 400, to ensure that the project teams are fully informed and that there are no miscommunications. The BIM Engineers are essential to the success of any construction project as they provide the necessary level of detail and accuracy to ensure that the project runs smoothly and efficiently.

Read more about LOD and BIM at the BIMForum.