Download the most current Level of Development Specification (Part I and II) by clicking here.
Latest Version
The BIMForum has released the 2021 Level of Development (LOD) Specification. Click here to downloadPart I and the Guide.Click here to downloadPart II.
Background
TheLevel of Development (LOD) Specificationis a reference that enables practitioners in the AEC Industry to specify and articulate with a high level of clarity the content and reliability of Building Information Models (BIMs) at various stages in the design and construction process. TheLOD Specificationutilizes the basic LOD definitions developed by the AIA for theAIA G202-2013 Building Information Modeling ProtocolForm[1]and is organized by CSI Uniformat 2010[2].It defines and illustrates characteristics of model elements of different building systems at different Levels of Development. This clear articulation allows model authors to define what their models can be relied on for, and allows downstream users to clearly understand the usability and the limitations of models they are receiving. The intent of this Specification is to help explain the LOD framework and standardize its use so that it becomes more useful as a communication tool. It does not prescribe what Levels of Development are to be reached at what point in a project but leaves the specification of the model progression to the user of this document. To accomplish the document’s intent, its primary objectives are:
- To help teams, including owners, to specify BIM deliverables and to get a clear picture of what will be included in a BIM deliverable
- To help design managers explain to their teams the information and detail that needs to be provided at various points in the design process
- To provide a standard that can be referenced by contracts and BIM execution plans.
It should be noted that this Specification does not replace a project BIM Execution Plan (BIMXP), but rather is intended to be used in conjunction with such a plan, providing a means of defining models for specific information exchanges, milestones in a design work plan, and deliverables for specific functions.
In 2011 the BIMForum initiated the development of this LOD Specification and formed a working group comprising contributors from both the design and construction sides of the major disciplines. The working group first interpreted the AIA’s basic LOD definitions for each building system, and then compiled examples to illustrate the interpretations. Because BIM is being put to an ever increasing number of uses, the group decided that it was beyond the initial scope to address all of them. Instead, the definitions were developed to address model element geometry, with three of the most common uses in mind – quantity take-off, 3D coordination and 3D control and planning. The group felt that in taking this approach the interpretations would be complete enough to support other uses.
[1]AIA Contract DocumentG202-2013, Building Information Modeling Protocol Formis part of a new series of digital practice documents the AIA published in June 2013. The AIA’s updated digital practice documents consist ofAIA E203™–2013, Building Information Modeling and Digital Data Exhibit,AIA G201™–2013, Project Digital Data Protocol Form, andAIA G202™–2013, Project Building Information Modeling Protocol Form. For general information on the documents and downloadable samples seewww.aia.org/digitaldocs.For executable versions of the documents seehttp://www.aia.org/contractdocs.
[2]UniFormatTMNumbers and Titles used in this publication are from UniFormatTM, published by CSI and Construction Specifications Canada (CSC), and are used with permission from CSI. For a more in-depth explanation of UniFormatTMand its use in the construction industry visithttp://www.csinet.orgor contact CSI, 110 South Union Street, Suite 100, Alexandria, VA 22314. (800) 689-2900.
Previous Versions
BIMForum_LOD_2013_reprint.pdf
BIMForum_LOD_2014_reprint.pdf
BIMForum_LOD_2015_reprint.pdf
BIMForum_LOD_2016_reprint.pdf
BIMForum_LOD_2017_reprint.pdf
BIMForum_LOD_2018_reprint.pdf
BIMForum_LOD_2019_reprint.pdf
BIMForum_LOD_2020.zip
FAQs
What is BIM level of development? ›
BIM Level of Development (LOD) is an industry standard that defines how the 3D geometry of the building model can achieve different levels of refinement, is used as a measure of the service level required.
What is the difference between LOD 300 and LOD 350? ›By LOD 300, the elements are defined with exact dimensions and their relative positions bolstering precision. LOD 350 describes the information about an element precisely and outlines an element's relation and connection with other components.
What is the difference between LOD 300 and 400? ›For example, With LOD 300 the AHUs are unknown usually when construction documents are issued, so the contractor will coordinate size and location once the unit is purchased. Whereas with LOD 400, the unit is known, so the exact size and location is informed and might already be purchased and installed.
How many levels of development are used in BIM? ›The Six Levels of Development in BIM. As previously mentioned, the LOD applies for specific building systems and components, not the complete project. When design teams collaborate, the LOD indicates which areas of the design have already reached the construction documentation stage.
What are the 4 levels of BIM? ›https://
What is LOD in modeling? ›Level of Design / Development / Detail (LOD) is the overall state of your information model at a particular point in its design process. This includes not only graphical objects, but also the data associated with the objects.
What does LOD 200 mean? ›LOD 200: The Model Element is graphically represented within the Model as a generic system, object, or assembly with approximate quantities, size, shape, location, and orientation. Non-graphic information may also be attached to the Model Element.
What is the LOD at BIM Level 2? ›LOD defines the content of a BIM project at different stages in its development and refers to two elements: the geometry or visual representation of a project, and the attached data. It is the attached data that creates intelligent objects, and sets BIM modelling apart from dumb extrusions or polygons.
How does the level of development LOD help in the BIM lifecycle? ›As a basic premise the LOD specifications acknowledges the different phases for lifecycle BIM, and help specify the needs at every stage. It tries to answer questions like: What are requirements for geometric content and model data for each discipline and each “level”.
What is a Level 1 BIM? ›Level 1 BIM
Level 1 BIM involves using both 3D CAD and 2D drafting. While 3D CAD is used for conceptual works, 2D is used for the generation of statutory approval documentation and Production Information. At this level, data sharing happens electronically using a common data environment (CDE) managed by the contractor.
What is a Level 3 BIM? ›
BIM Level 3 is an integrated working method using a common data environment (CDE), which enables better collaboration and model evaluation irrespective of the software solution used by each team member.
What is Level 2 BIM Maturity? ›Level 2 BIM
Managed 3D environment with data attached, but created in separate discipline-based models. These separate models are assembled to form a federated model, but do not lose their identity or integrity. Data may include construction sequencing (4D) and cost (5D) information.
It specifies the characteristics of different levels used for defining the detail and extent of information required to be exchanged and delivered throughout the life cycle of built assets. It gives guidelines for principles required to specify information needs.