LOD 100 vs 200 vs 300 vs 350 vs 400 vs 500: Complete BIM Level of Development Guide

Level of Development — LOD — is the framework BIM teams use to describe how much detail a model element actually contains. The framework was published by the BIMForum in the United States and is now the de-facto standard reference on most U.S. projects. The framework defines six levels: LOD 100, 200, 300, 350, 400, and 500. Each level corresponds to a specific combination of geometric accuracy, location precision, and embedded information. Picking the right LOD is a project-execution decision that shapes cost, schedule, and downstream usability of the model.

Why LOD matters

Models built at the wrong LOD waste money. Over-modeled elements consume billable hours that the deliverable does not require. Under-modeled elements fail at the downstream use — clash detection misses real conflicts because the geometry is imprecise, or a fabricator cannot use the model because critical assembly data is missing. The point of the LOD framework is to make the modeling target explicit and contractual, so the BIM team builds to the agreed level of fidelity — not more, not less.

LOD 100 — Conceptual

LOD 100 elements are symbolic representations — masses, blocks, or placeholders that show the existence and approximate location of a building element without committing to geometry, size, or quantity. Typical LOD 100 use: early design feasibility, massing studies, energy analysis at the conceptual stage.

A column at LOD 100 might be represented as a vertical line in the model, with no cross-section, no actual width or depth, and no embedded material data. The model element communicates "there is a column here, approximately" and nothing more.

LOD 200 — Approximate

LOD 200 elements have approximate geometry, size, location, and quantity. Generic systems are represented with non-specific objects — a "wall" without a specific wall type, a "beam" without a specific section size. Typical use: design development, preliminary clash detection, early cost estimation.

A column at LOD 200 might be a generic rectangular extrusion with approximate dimensions, located within roughly the right position. Material is not assigned; specific section size is not committed.

LOD 300 — Documented

LOD 300 elements have accurate geometry, size, location, quantity, and orientation. Specific systems are committed — a wall has a specific wall type with specific layers, a beam has a specific section size. Typical use: construction documentation, permit sets, contractor pricing, coordination across disciplines.

A column at LOD 300 is a specific section (e.g. W12×26) located precisely, oriented correctly, with material assigned. Connections are shown schematically. Fabrication details are not yet present.

LOD 350 — Coordinated

LOD 350 elements carry everything LOD 300 carries, plus information about how the element connects and interfaces with other systems. Connection details, penetration locations, attachment assemblies, and adjacent element relationships are explicit. Typical use: multi-trade coordination, advanced clash detection, fabrication preparation.

A column at LOD 350 includes the connection to the beam, the base plate, the anchor pattern, and the interface with the foundation. The geometry is accurate enough that clash detection catches real conflicts (e.g. an HVAC duct passing through the column).

LOD 400 — Fabrication-Ready

LOD 400 elements carry full fabrication information: bolt holes, weld preparations, assembly information, material specifications, and fabrication tolerances. The model element is sufficient for a shop to fabricate the piece directly from the model — no further design or detailing is required. Typical use: steel fabrication, precast detailing, MEP spool fabrication, modular construction.

A column at LOD 400 has every bolt hole, every weld, every cope, every chamfer, every shop note. The Tekla, Advance Steel, or Revit model carries enough information that CNC output (NC files, KISS files) can drive the fabrication equipment directly.

LOD 500 — As-Built

LOD 500 elements are field-verified as-installed representations. Geometry, location, orientation, and embedded data reflect actual installed conditions, not design intent. Typical use: facility management handoff, post-construction asset management, retrofit and renovation planning.

A column at LOD 500 has been measured in place after installation. Any deviation from the LOD 400 design (e.g. a column installed slightly out of plumb, a connection modified in the field) is reflected in the as-built model.

LOD comparison table

A quick reference for what each LOD includes:

• LOD 100 — symbolic, approximate location only
• LOD 200 — generic geometry, approximate size and location
• LOD 300 — specific systems, accurate geometry, quantity, orientation
• LOD 350 — LOD 300 plus connection and interface detail
• LOD 400 — fabrication-ready, with assembly and material specifications
• LOD 500 — field-verified as-installed

How to pick the right LOD for your project

The project execution plan (PxP) should specify the LOD target for each discipline at each project phase. The wrong-LOD trap most commonly looks like one of three patterns: modeling at LOD 400 when LOD 300 would do (paying for fabrication detail on elements that will never go to a shop), modeling at LOD 200 when LOD 350 is required for coordination (clash detection misses conflicts because geometry is imprecise), or specifying LOD 500 on speculation (committing to as-built deliverables that nobody plans to verify in the field).

LOD 350 vs LOD 400 — the most commonly confused pair

LOD 350 and LOD 400 are often used interchangeably by people new to BIM, but they are distinct. LOD 350 means the model is accurate enough for coordination — clash detection works, connection geometry is correct, but fabrication-specific information (bolt holes, weld preps, material specs) may be missing. LOD 400 means the model carries enough information that a shop can fabricate from it directly. The labor difference between LOD 350 and LOD 400 on a steel-intensive project is often thirty to fifty percent of the modeling hours, so the distinction is contractually significant.

LOD 400 vs LOD 500 — the as-built confusion

LOD 400 is fabrication-ready design intent — what the shop should build. LOD 500 is field-verified as-installed — what was actually built. The two are not the same: actual installation always deviates from design intent in small ways, and LOD 500 captures those deviations. Most projects do not require LOD 500 deliverables. The ones that do are usually facility-management-driven (the owner wants an as-built model for ongoing operations) or retrofit-driven (a future renovation needs an accurate as-installed baseline).

BIM 400 vs LOD 400 — terminology cleanup

You will sometimes see "BIM 400" used as shorthand for LOD 400. The two phrases mean the same thing: a BIM model element built at LOD 400. The BIMForum framework uses LOD as the canonical term; "BIM 400" is a colloquial variant that floats around in proposals and procurement language. They are interchangeable in conversation; LOD is the formal term.

Bottom line

LOD is a contractual specification, not a quality grade. Higher LOD is not better — it is more detailed. The right LOD for a given element on a given project depends on the downstream use of that element. The point of the framework is to make the modeling target explicit, so the BIM team builds to the agreed level and neither over-bills for unnecessary detail nor under-delivers on critical fidelity. Specify LOD per discipline per phase in the project execution plan, and the rest of the project gets materially easier.

• What is LOD 400 in BIM?
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