BIM standards continue to evolve, and there is an ongoing debate in the BIM communities regarding the use of LOD (Level of Development/Level of Detail/Level of Definition/...) scales.
Some argue for the use of specific scales, while others, like Level of Information Need, prefer to define requirements using plain language.
In this article, we will explore the benefits and considerations of both approaches and how Plannerly, a BIM management software, supports all options! 😃
🎥 Understanding BIM LOD Scales Video Demo
Understanding LOD Scale in BIM Modeling
An LOD scale isn't just a bunch of numbers; it's a standard that aims to outline the geometrical needs, element reliability, and necessary information in a BIM model at a specific project stage.
By utilizing predefined scales, you can appear to align with industry standards.
However, relying solely on a simple number scale has led many projects into debates and potential risks.
Challenges with Consistent LOD Scale Application
While standards aim to ensure the consistent application of the appropriate LOD scale across projects, the reality is far more complex due to numerous factors to consider.
These standards try to ensure that the appropriate LOD scale is applied consistently across projects, however in reality this is difficult as there are so many aspects that should be considered.
This has been highlighted by the decision of the BIM Forum to roll back the use of the LOD scale to now only cover geometry and reliability. Previously, the BIM Forum LOD scale also encompassed element information requirements - these are now managed separately in another table.
Unfortunately, even just focusing on the combination of geometry and its reliability could be a mistake - this notion of a strict LOD scale (with limited numbers) enforces that as the geometry gets more detailed, it must also get more reliable.
What about cases where teams simply need basic BIM geometry but with high reliability?
For instance, when only the outer outline of an existing building is needed (basic geometry), yet the massing boundary must be dependable for land purchase decisions (high reliability).
On the other hand, there are scenarios that call for detailed geometry but with lower reliability.
For instance, teams might require intricate chair models for visually appealing renders to market office spaces, without concerning themselves with the exact chair type to be used in reality.
It's a spectrum of needs, and unfortunately, even the most recent LOD scales can't neatly address all these situations.
Flexibility and Customization in LOD Requirements
Plannerly understands the importance of giving you the freedom to use different scales, be flexible in your approach, follow the Level of Information Need framework, and create your own requirements by selecting combinations of geometry and reliability.
You can even specify the desired level of accuracy (LOA) (from the USIBD) for your models.
This flexibility empowers you to define your requirements for all information containers on your project.
Plus, when you set your LOD requirements within Plannerly, the symbolic representation of the element automatically adjusts to show the chosen LOD scale.
This feature helps you see the expected level of detail for each element in the model clearly.
Information Requirements in BIM
Understanding that BIM encompasses both geometry and information content, Plannerly extends its support to information requirements as well.
Just as users can define geometrical requirements using LOD scales or plain language, they can also articulate detailed information requirements!
Information requirements can be imported into the information requirements database or generated directly with a connection to the buildingSMART data dictionary (bSDD) (from buildingSMART), providing users with a comprehensive toolkit to ensure accurate and standardized information requirements.
The Flexibility of Plannerly
Plannerly is a flexible project requirements planning software that empowers users to choose the approach that aligns best with their specific needs and project requirements.
Whether users prefer the use of LOD scales or the versatility of plain language using Level of Information Need, Plannerly accommodates both options seamlessly (and also a combination of them both!).
Ultimately, the choice between LOD scales and plain language depends on factors such as project complexity, stakeholder preferences, and industry standards.
