BIM Design Technology
Image of Lego character in different levels of detail

LOD: The Matrix Glitch in BIM’s Reality 

Inspired by various online content, our team recently engaged in a thought-provoking discussion that sparked the creation of this article. Anyone even remotely familiar with BIM would have come across the term LOD, which refers to Level of Detail or Level of Development or shall we say: Level of Discussion?. Since the beginning of the digital transformation in the construction industry, this term has been used. Or maybe misused? Therefore, we bring you our thoughts on this topic. 

LOD Basic Framework 

First, let’s dive into the world of LOD and take a trip back in time to where it all began. In the late 1970s and early 1980s, when computers and 3D video games were taking off, the concept of Levels of Detail emerged. It was a solution to render complex scenes while conserving processing power, given the hardware limitations of the time. 

Fast forward to today, LOD in computer graphics represents the intricacy of a 3D model. It strikes a perfect balance between quality and efficiency, seamlessly presenting simplified models for distant objects and gradually revealing intricate details as they come closer.  

LOD in BIM 

Naturally, the concept of Level of Detail/Development (LOD) seemed relatable among early BIM enthusiasts. In 2004, Vico Software introduced the “Model Progression Specification,” which laid the foundation for the idea of varying detail. Recognizing its potential, the American Institute of Architects (AIA) embraced LOD in 2008 and presented five distinct Levels of Development (LOD 100-LOD500) in the Building Information Modeling Protocol. This protocol, globally recognized and revised in 2013, has become a guiding force for BIM standards worldwide. Many countries have adopted the AIA standards, while others, like New Zealand, have introduced their unique variations. 

Current Landscape 

When it comes to the utilization of LOD, organizations have developed their own interpretations and versions, while software vendors also contribute their expertise to the matter. However, these variations can pose significant challenges in collaboration among multiple stakeholders.  Understanding these variations in LOD interpretations is crucial, especially when considering their practical applications beyond visualization tools. This leads to the question of LOD’s broader relevance in BIM – beyond virtual viewing and into aspects of maintenance, design, and construction. 

LOD’s practical use? 

We invite you to consider, besides using it in your viewer, VR, AR, XR experience, or anything related to virtually viewing your models, how is LOD relevant when it comes to BIM? What does it say? It says close to nothing about maintaining, designing, or building. For example: Would you prefer an air handling unit that includes detailed modeling of every component, like filters, bolts, and nuts, with moveable filters, heaters and separately selectable elements? Or is a parametric, machine-readable, light, fast, and accurate family more valuable, one that provides essential information, whether through specific parameters (such as the type of filter and maintenance instructions for that filter) or through visibility (like the overall shape and dimensions of the unit, where to connect and its maintenance area)? 

 
The LOD Gap 

From our observations, the LOD framework seems abstract in its modern use. Its existing categories may not resonate with actual design, building and maintenance processes. Users of LOD try to encapsulate many concepts, such as level of detail, which phase you need which information, in how much detail you want to design, which results in an oversimplified approach. When the question should be: Which information do I need at which points during the design, construction and maintenance phase. In the context of large-scale construction projects utilizing the Level of Development/Detail (LOD) framework, it is frequently observed that critical details and the underlying rationale essential for the optimization of engineering, construction, and maintenance processes are inadvertently overlooked. Stakeholders need to understand how the depth of modeling at each phase relates to budgeting, planning, and execution. 

Despite the extensive efforts to define and refine the LOD framework in BIM, the gaps remain in its universal understanding and application. Stakeholders can interpret it differently, and this can lead to misinterpretation of their application. We should put the required information central, and the Level of Detail will follow. 

Final Thought 

LOD aims to make the construction journey simpler by specifying model details throughout the project phases. While the core concept of LOD is insightful for understanding model complexities, it shouldn’t be the only focus of a project as it can be unclear and detached from real-world construction processes. Relying too heavily on it might confuse stakeholder communication and, in turn, project outcomes. 

Today’s LOD framework either receives criticism or serves as a beginner’s guide to BIM. We believe that LOD should be only used for where it was designed for. LOD could be great with walking through models in web browsers, or some similar matter. Reimagining its practical application might be the way forward. 

We shared our insights, now we leave you with the thought. What’s your view on LOD, and how would you leverage it?