BIM adoption rates continue to rise, project teams are more distributed than ever, and models are increasingly more complex. It's in this environment that the importance of LOD to BIM projects continues to grow. Level of Development, once an optional specification in a BIM Execution Plan, is increasingly a necessary tool for any project that utilizes a shared model across disciplines.

Here are 5 reasons why LOD has become more powerful than ever.

1. It provides a shared language between disciplines

When architects, M/E/P engineers, contractors, and owners all look at the same model, it's easy for each to have a different expectation of what is and isn't "finished" in a given element. LOD provides a common language by which all parties can understand and utilize the model. With LOD attached to every element in the model, everyone can immediately identify what's been modeled to a detailed, installable, and MEP constructible state (LOD 400), or what elements only have approximate location and basic shape (LOD 250). The value of this common language cannot be understated, as it eliminates reams of discussion about expectations in multi-disciplinary projects.

2. It avoids using untrustworthy information

This is the big one, especially as projects grow more complex. Contractors and subcontractors can't build things to an LOD that hasn't been achieved. This might mean that the HVAC design is only at conceptual (LOD 100) while the structure has reached MEP constructible levels (LOD 400), creating clashes down the road or erroneous quantities. By clearly delineating what has been modeled at what level of detail, LOD avoids unproductive use of resources based on unreliable information.

3. It provides a clear scope of BIM deliverables

For owners and design managers who need to know what to expect in a BIM deliverable from any given discipline, LOD removes ambiguity. By defining what level of detail each discipline must achieve (e.g. structural steel at LOD 350 per the BIM Execution Plan), all parties have a clear scope to reference at any given point in the project.

4. It reduces rework and identifies gaps in the model

Closely related to the last point, elements of a model can be identified at a certain LOD and compared to a target LOD for a specific use (e.g. clash detection). This can help avoid rework by catching modeling gaps before they cause headaches later in the project. The further along a project is, the more resources it takes to make changes. Finding a gap at the LOD 200 (approximate quantity and size) is much easier to remedy than discovering it at LOD 400 (installable).

5. It gets the most out of the model for years to come

LOD 500, the as-constructed and field verified level of detail, is a huge boon to facilities management. The more information that's included in this level of detail, the more useful the model is for operations and maintenance. Many AEC projects are looking to gain value from their BIM model long after construction is over. By utilizing the LOD framework and specifying deliverables at higher levels of detail, projects can maximize the value of their BIM model for facility management years after project closeout.

Why it matters now more than ever

Projects are more distributed than ever before and see collaboration across more disciplines while only using a single shared model. This means there's more potential for communication issues across stakeholders. By utilizing the LOD specification, projects can arm themselves with one of the few tools available for managing a distributed, multi-disciplinary design team working in a shared BIM model.

If you want to dive into what's included at each level of detail (from conceptual model to as-constructed), this post on the importance of LOD to BIM provides an excellent overview of the AIA and BIM Forum standards for each level.