LOD (Level of Development) tells a modeler how much geometric detail and reliability to build into a BIM element, and it should be specified separately for each building system, not once for the whole project. Getting this decision right before modeling starts is what keeps a scan-to-BIM budget on target.
This post is for architects and building owners who already understand roughly what LOD means and need to decide what to specify, system by system, on an actual scan-to-BIM order.
Why specify LOD per system instead of one number for the whole building?
Because different systems carry different risk if they’re under-modeled. Getting the shape of a wall slightly wrong is a minor issue. Getting a duct routing wrong when a mechanical contractor is coordinating trade clashes is an expensive one. P3D’s standard recommendation is to match LOD to how the model will actually be used: architecture and structure at LOD 300 for construction documents, MEP at LOD 200 if the trade will field-verify before installing, and LOD 350 reserved for systems where multiple trades need to coordinate clashes digitally before anyone touches the building.
What’s the practical difference between LOD 200, 300, and 350?
LOD 200 gives you approximate size, shape, and location — enough for space planning, feasibility studies, and early design, but not enough to build from. LOD 300 gives you accurate, dimensionally reliable geometry suitable for construction documents and general trade coordination. LOD 350 adds the interfaces and connections between systems — the level where a mechanical duct and a structural beam are modeled precisely enough to catch a clash before it happens on site. Each step up requires more modeling time, which is why LOD is the biggest single driver of price in a scan-to-BIM deliverable, referenced in the BIMForum Level of Development Specification, the industry standard this scale is based on.
What happens if you specify a lower LOD than the project actually needs?
The model looks complete but isn’t reliable enough for the decision being made with it. A common failure mode: an owner orders LOD 200 to save money, then uses the model for construction bidding. Contractors price against geometry that was never meant to be dimensionally exact, and the gap between the model and the real building shows up as a change order once work starts. LOD should be chosen based on what the model will be used for, not just the smallest number that fits the budget.
What happens if you specify a higher LOD than the project needs?
You pay for precision nobody uses. LOD 350 MEP coordination on a project where the mechanical contractor is going to field-verify every run anyway adds real modeling hours for detail that gets overwritten in the field. This is the more common overspend P3D sees — owners default to the highest LOD out of caution, without mapping it to how each system will actually be used downstream.
How does this play out on a real specification?
A Grand Rapids design-build firm renovating a mid-size medical office building specified LOD 300 for architecture and structure — enough to issue for construction documents — and LOD 200 for MEP, since the mechanical subcontractor planned to field-verify existing ductwork before tying in new equipment. That split kept the modeling scope focused on the systems the design team needed dimensionally exact, without paying for full LOD 350 coordination on ductwork that was getting re-verified in the field regardless.
Where does LOD specification get harder than it looks?
Mixed-use and heavily renovated buildings make this decision harder, because different areas of the same building may warrant different LOD. A shell space being gutted for a new build-out may only need LOD 200 for early planning, while an occupied, fully finished wing being renovated in place may need LOD 300 to avoid surprises. There’s no substitute for a short scoping conversation before the scan — LOD is a decision made with the project team, not a default P3D picks on its own.
LOD decisions also affect how a project’s modeling budget gets allocated across systems. On a typical commercial renovation, architecture and structure often make up the majority of the square footage a modeler has to build, so even a modest LOD increase there compounds across the whole floor plan. MEP, by contrast, is usually a smaller share of total modeled elements, which is part of why lowering MEP’s LOD when a contractor plans to field-verify anyway produces real savings without touching the systems the design team is actually relying on for construction documents.
None of this is decided in isolation. P3D typically walks through LOD per system as part of scoping a scan-to-BIM order, using the intended use of the model — design development, construction documents, or facility management — to recommend a starting point, which the architect or owner then confirms or adjusts.
Who decides what LOD to specify — the architect, the owner, or P3D?
It’s a joint decision. P3D can recommend LOD based on how the model will be used, but the architect or owner ultimately confirms it, since they know how the model fits into design, bidding, or trade coordination downstream.
Can LOD be increased later if the project scope changes?
Yes. Since the underlying point cloud is captured at full detail regardless of LOD, going back to model additional elements at a higher LOD later doesn’t require a re-scan — just additional modeling time against data P3D already has.
Does LOD 350 mean the model is “more accurate” than LOD 300?
Not exactly. Both levels are built from the same measured point cloud, so the underlying dimensional accuracy is the same. LOD 350 adds more detail about how systems connect and interface — it’s about completeness of information, not raw measurement accuracy.
Is LOD the same thing as LOD used in the BIMForum specification?
Yes — P3D uses the BIMForum Level of Development Specification as the reference standard for LOD definitions, so a client’s architect or engineer working from the same standard will interpret the deliverable consistently.
Related reading: Matterport to BIM: How Reality Capture Feeds Construction Documentation · Scan-to-BIM Workflows: What Architects Need to Know · Understanding LOD in BIM from Reality Capture (companion piece — general LOD overview)
Not sure what LOD your project needs? Call 616-312-3947 or visit perspective3-d.com/contact.