Beyond Geometry: Transitioning from LOD to Level of Information Need

In the early days of BIM, teams obsessed over how realistic a model looked. Level of Development (LOD) became a catch-all for quality. But in an ISO 19650 world, realism isn’t the goal—usefulness is. If you still request LOD 300 for everything, you may be paying for data you don’t need while missing the data that actually matters.

• ▹LOD (Level of Development): Focuses on graphical complexity of a model element.
• ▹Level of Information Need (LOIN): Defines the minimum geometric, alphanumeric, and documentary data required for a specific project task or decision.

Why it matters: LOD tells you how detailed an object looks; LOIN tells you what information you actually need to make decisions.

Many teams still rely on LOD 100–500 as a blunt instrument. This often produces visually impressive models but ignores the critical metadata required for analysis, costing time and introducing errors.

Example: A pump modeled in LOD 400 might show every bolt and cooling fin—impressive—but if it lacks flow-rate parameters and the maintenance manual, it’s useless for facility management.

LOIN Solution: Specify what’s needed for the project phase:

• ▹Geometry: Low-detail box
• ▹Performance Data: High-density numeric data
• ▹Documentation: Linked PDF “Manufacturer Data Sheet”

Your BIM Execution Plan should define each element by:

1. ▹

   Geometrical Information: Symbolic line, simplified mass, or high-fidelity 3D object?
   Example: A structural column in schematic design may only need a simplified extrusion.

2. ▹

   Alphanumerical Information: Parameters like U-values, acoustic ratings, or COBie data.
   Example: An HVAC unit may require airflow capacity, power rating, and maintenance schedule in the model.

3. ▹

   Documentation: External files linked to the object, such as O&M manuals, warranties, or Scan-to-BIM verification reports.

Pro Tip: Use Revit’s Assembly Code or Keynote parameters to link model elements to your project specifications. This ensures alphanumeric data stays synced with official documents.

LOIN adapts to the project phase:

• ▹Design Phase: Focus on clearance zones, simplified geometry, and preliminary performance data.
• ▹Construction Phase: Add fabrication-level geometry, precise data, and contractor-ready documentation.
• ▹Handover Phase: Complete asset information model with COBie-ready data and O&M manuals.

Benefits of applying LOIN:

• ▹Faster model performance: Removing unnecessary geometry keeps Revit files lean.
• ▹Better coordination: Focused data prevents clashes before they happen.
• ▹Automated schedules: Prioritized alphanumeric data allows equipment schedules to populate automatically.
• ▹Cost efficiency: Avoids over-modeling elements that don’t add value.

Visual Tip: A 3-column diagram mapping Geometry | Data | Documentation per phase can help stakeholders quickly grasp the shift.

On a large hospital project, applying LOIN instead of default LOD 400 across all MEP elements:

• ▹Reduced modeling hours by 30%
• ▹Avoided missing flow and maintenance data
• ▹Enabled automatic generation of equipment schedules
• ▹Improved clash detection before construction

Lesson: Modeling only what is needed per task saves time, reduces errors, and supports informed decision-making.

1. ▹Identify project tasks per phase (design, construction, handover).
2. ▹Define required geometry, data, and documentation for each element.
3. ▹Map requirements to Revit parameters, COBie fields, or linked documents.
4. ▹Review and audit for compliance regularly.
5. ▹Iterate based on feedback from design, construction, and FM teams.

• ▹Treating LOIN as “lower LOD”: Remember, LOIN is purpose-driven, not just less detailed.
• ▹Skipping documentation linkage: Missing PDFs or O&M manuals undermine handover value.
• ▹Ignoring team buy-in: LOIN adoption requires clear communication and leadership support.
• ▹Overlooking phase-specific needs: Each stage has different priorities—don’t apply one standard across all phases.

Quantifying benefits makes LOIN adoption easier to justify:

• ▹File size reduction: Lean models improve performance
• ▹Time savings: Less unnecessary modeling = fewer billable hours wasted
• ▹Error reduction: Fewer clashes and missing data prevent rework
• ▹Better handover: Accurate asset information supports FM and compliance

• ▹BS EN 17412-1: Level of Information Need Concepts
• ▹CEN/TC 442: BIM Standardization Committee

Final Word:

Transitioning from LOD to Level of Information Need marks a mature BIM process. It shifts the conversation from how it looks to how it works, ensuring your engineering and architecture data adds value across the building lifecycle.