What is LOD in BIM?
LOD (Level of Development) in BIM describes how detailed and reliable the model elements are—from conceptual placeholders (LOD 100) to as-built, fabrication-ready geometry (LOD 400). It matters for BIM estimating, quantity takeoffs, and coordination because it sets expectations for what the model can support.
LOD levels (summary)
| LOD | Typical use |
|---|---|
| LOD 100 | Concept / massing; not for takeoffs |
| LOD 200 | Generic elements, approximate quantities |
| LOD 300 | Specific elements, model elements = construction; suitable for many quantity takeoffs |
| LOD 350 | 300 + interfaces with other systems (e.g., clashes) |
| LOD 400 | Fabrication-ready; assembly and manufacturing |
| LOD 500 | As-built / field-verified |
Why LOD matters for estimating
- Scope — Estimating from LOD 300 assumes the model represents the design; LOD 400 implies fabrication-level detail.
- Accuracy — Quantities from a higher LOD are typically more reliable for cost estimates.
- Deliverables — Many BIM estimating and BIM-IQ workflows tag estimates with the LOD so everyone knows what the numbers are based on.
LOD 300 vs LOD 400
- LOD 300: Model elements are specific and suitable for coordination and most BIM quantity takeoffs; not necessarily fabrication-ready.
- LOD 400: Enough detail for fabrication, assembly, and installation; often used by MEP and specialty contractors for detailed estimates.
Understanding LOD helps you know what you can reliably estimate from a BIM and how to document your assumptions. BIM-IQ produces LOD-aware estimates so your deliverables match the model’s level of development.
For how LOD 350 and LOD 400 play out on data center and fab MEP work, see BIM and VDC for Texas data centers and fabs.
Black Forge Technology can help — Get LOD-aware estimates with BIM-IQ or implement consistent BIM workflows with our consulting. Book a free assessment or contact us today.