BIM Forum LOD spec guide
Written by Kelar Pacific

Construction Design Phases vs BIM Levels of Development – Part 3 of 4

What are the Definitions of BIM Levels of Development?

The following reflects the general consensus of the most widely used LOD Definitions:

  • LOD 100: A Conceptual Model where parameters like area, height, volume, location and orientation are defined.
  • LOD 200: An Approximate Geometry Model where elements are modeled with approximate quantities, size, shape, location and orientation.*
  • LOD 300Precise Geometry Modeling and shop drawings where elements are defined with specific assemblies, precise quantity, size, shape, location and orientation.*
  • LOD 350Includes Model Detail and element that represent how building elements interface with various systems and other building elements with graphics and written definitions.
  • LOD 400: Model elements are modeled as Specific Assemblies with Complete Fabrication, assembly, and detailing information in addition to precise quantity, size, shape, location and orientation.*
  • LOD 500As-Built Elements are modeled as constructed assemblies for Maintenance and operations.*

*Can include non- geometric information to the model elements.

How do you use BIM LOD Specification Workbooks?

BIM LOD Specification Workbooks are often required by the client and updated with each revision of a project’s BIM file. If so, it’s important for the prime and subcontractors to base the related progression of their cost estimates and schedules accordingly. The example below is created by the BIM Forum.

The BIM Specification is not a set of requirements as to what is modeled, when, or by whom. Rather it is a language by which users can define these requirements for their own firms or projects. A BIM Specification provides the following benefits:

  • Helps teams including owners to specify BIM deliverables and get a clear picture of what will be included in a BIM deliverable.
  • Helps design managers explain to their teams the information and detail that needs to be provided at various points in the design process, and to track progress of their models.
  • Allows downstream users to rely on specific information in models they receive from others.
  • Provides a standard that can be referenced by contracts and BIM execution plans.

View or download a copy of the LOD Specification Worksheet:
BIM Forum 2016 Level of Development Specification Workbook (Excel)

BIM Lod Specification Workbook Example

We will conclude this 4 part topic on Construction Design Phases vs BIM Levels of Development in Article 4.

Ed Wenz

Sage Estimating Consultant

5D BIM Estimating/eTakeoff


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