Rebar modeling is one of the places where over-delivering wastes real time and effort, and under-delivering creates genuine site problems — so getting clear on what LOD level a project actually needs, rather than defaulting to "as detailed as possible," matters more here than almost anywhere else in structural BIM.
What LOD 350 rebar actually looks like
At LOD 350, rebar is modeled with accurate sizing, spacing, and general placement sufficient for coordination — confirming reinforcement doesn't clash with embedded MEP sleeves, conduits, or other structural elements — but without full fabrication-level detail like exact bend schedules, lap splice locations specified to the precise bar, or bar mark numbering ready for a fabricator to cut steel from directly.
What LOD 400 rebar actually adds
| Aspect | LOD 350 | LOD 400 |
|---|---|---|
| Bar sizing and spacing | Accurate | Accurate |
| Coordination-ready (clash detection) | Yes | Yes |
| Bend schedules | Generally not included | Fully detailed, fabrication-ready |
| Lap splice locations | General zones, not bar-specific | Specific, bar-by-bar placement |
| Bar marks / cutting list | Not typically generated | Generated directly for fabrication |
| Modeling time investment | Moderate | Significantly higher |
When LOD 350 is genuinely the right call
If the rebar fabricator is working from traditional 2D bar bending schedules produced separately (common in many Indian construction projects, especially outside fully ISO 19650-aligned ones), modeling rebar to LOD 400 in Revit is often wasted effort — you're paying for detail nobody downstream is going to consume. LOD 350 gets you the coordination value (clash avoidance with MEP and other structural elements) without the time investment of fabrication-level detail that's being duplicated elsewhere anyway.
When LOD 400 is worth the investment
On projects where the BIM model itself is the fabrication source of truth — increasingly common on large infrastructure and ISO 19650-aligned projects with international clients — LOD 400 rebar isn't optional polish, it's the actual deliverable the fabricator depends on. Skimping here just shifts the detailing work downstream to someone reconstructing it manually from an incomplete model, usually under worse time pressure.
The conversation to have before modeling starts
This decision should be explicit in the project's EIR or BEP/IPP (see our EIR writing guide), specified by structural element type and project stage — not assumed, and definitely not left to be decided informally partway through the project once someone notices the model is "more detailed than we needed" or, worse, "not detailed enough for the fabricator."
LOD specification by element and discipline, including rebar detailing decisions, is covered in our structural and process training across the Structure and Apex plans. Full curriculum on the Programs page.
