lod
(level of development)
lod (level of development)
In this article, we explain what LOD is and why it plays a key role in CAD/BIM projects. We’ll cover the standard LOD levels (100–500) and clarify how they differ. How do you select the right LOD for your project? How does LOD affect cost, scope, and the practical usability of your model? The answers are outlined below.
WHAT IS LOD?
LOD (Level of Development) is an international standard that defines how detailed and complete a given element is within a BIM/CAD model. It covers both the geometry (i.e., the visual representation of the component) and the technical information (such as material, manufacturer, or connections).
OD does not refer to the “quality” of the model in an aesthetic sense, but rather to the accuracy and usability of elements at a given stage of the project.
By using defined LOD levels, all project stakeholders—investors, designers, contractors, and engineers—gain a clear understanding of what the model includes, how it can be used, and what is still missing (especially during early design stages).
LOD LEVELS
There are typically six standard LOD levels:
DESCRIPTION:
The model represents the basic shape and size of elements, without detailed information.
APPLICATIONS:
Concept design, preliminary cost estimation, functional layout.
DESCRIPTION:
The model becomes more refined, incorporating approximate quantities, dimensions, shapes, and element locations.
APPLICATIONS:
Schematic design, initial interdisciplinary coordination.
DESCRIPTION:
The model includes geometric data, precise dimensions, shapes, and object components.
APPLICATIONS:
Detailed design, technical documentation.
DESCRIPTION:
The model includes detailed assemblies and information suitable for prefabrication or on-site installation.
APPLICATIONS:
Assembly coordination, clash detection, prefabrication.
DESCRIPTION:
The model contains all the information required for fabrication and installation.
APPLICATIONS:
Production, material procurement, execution.
DESCRIPTION:
At this stage, the model contains information about the installed and operational building elements, reflecting the real-world conditions of the facility.
APPLICATIONS:
As-built documentation, facility management.
HOW TO SELECT THE RIGHT LOD LEVEL FOR YOUR PROJECT’S BUDGET AND SCOPE?
A well-selected level of development ensures an optimal balance between model precision and the actual needs of the investor or designer. Each successive LOD level means more data to collect and process, which translates into more modeling hours and more complex interdisciplinary coordination. It also increases hardware and software requirements.
The higher the LOD, the greater the precision—but also the higher the cost.
For example, a piping model at LOD 200 includes only approximate routes and diameters. At LOD 400, every clamp, valve, and support must be modeled to match real-world specifications.
More doesn’t always mean better. In many projects—especially modernization efforts—a too high LOD can become an unnecessary expense.
For an architect: LOD 200–300 is sufficient for presenting spatial layout and functionality.
For an MEP engineer: LOD 300–350 is required for accurate coordination.
For a manufacturer: LOD 400 is essential when the model is used for fabrication.
For a facility manager: LOD 500 enables efficient asset and maintenance management.
A LOD that’s too low can lead to clashes, inaccurate estimates, or design errors.
A LOD that’s too high generates avoidable costs and increases project timelines.
Failure to define LOD in the contract often results in stakeholder misunderstandings and disputes.
LEVEL OF DETAIL (LoD) VS LEVEL OF DEVELOPMENT (LOD)
Level of Detail describes the amount of geometric information included in a model. A good example would be a door family in Revit. A low LoD means just a simple door mass. A high LoD includes detailed modeling of frames, handles, and hinges.
Level of Development refers to the completeness and reliability of information about the object. LOD defines whether the data is ready to be used for design, procurement, construction, or facility management. LOD 200 – general geometry, no material data. LOD 400 – precise geometry, defined material, manufacturer, catalog number, and connection details.