Levels of Development: Enabling coordination and collaboration

Levels of Development (LOD) refer to a standardised framework for defining the amount of detail and accuracy that should be included in a building information model (BIM) (US site) at different stages of a project.

The American Institute of Architects (AIA) and the Associated General Contractors of America (AGC) have established a commonly used LOD framework that breaks down the building model into specific levels:

LOD 100–conceptual design: At this stage, the model represents the basic shape and size of elements without detailed information. It’s used to convey the overall design intent.

LOD 200–schematic design: The model becomes more refined, incorporating approximate quantities, sizes, shapes and locations of elements. It helps in analysing spatial relationships and early design concepts.

LOD 300–detailed design: In this phase, the model includes geometric information, specific sizes, shapes and detailed object components. It’s used for producing construction documents and coordinating different disciplines.

LOD 350–construction documentation: The model includes detailed assemblies and fabrication or construction-level information. It’s used for generating construction documents and shop drawings.

LOD 400–fabrication and assembly: This level involves the creation of detailed models with specific assemblies and connections, suitable for fabrication and assembly purposes.

LOD 500–as-built or facility management: The model at this stage includes information about the installed and operational elements of the building, reflecting real-world conditions for maintenance and facility management.

Levels of Development (LOD) are integral to the construction industry because they allow model authors to clearly define the reliability of their models and help downstream users understand the limitations of the models they receive. By standardising the degree of reliability and accuracy required at each project stage, LOD minimises misunderstandings among stakeholders, optimises resource usage and aids proactive decision-making.

Do all AEC projects use Levels of Development (LOD)?

While Levels of Development (LOD) comprise a valuable framework widely used in the architecture, engineering and construction (AEC) industry, its adoption varies based on project-specific factors. Complex projects with intricate designs, those adhering to specific regulations and projects with experienced teams are more likely to implement LOD comprehensively. 

How is BIM involved in Levels of Development (LOD)?

Building information modelling (BIM) and Levels of Development (LOD) are closely intertwined in AEC. BIM forms the digital backbone for LOD implementation, enabling creation, management and sharing of detailed digital representations of building elements. LOD establish a framework that specifies the depth of detail and accuracy to be included in BIM models at various project stages. 

How are Levels of Development tracked in projects?

Levels of Development (LOD) are tracked in projects through an LOD matrix, an essential component of a BIM execution plan (BEP) (US site). In the LOD matrix, project teams define and outline LOD requirements for specific building elements and systems at various project stages. Responsibilities for creating and maintaining BIM models at each Level of Development are assigned to relevant stakeholders. The LOD matrix serves as a reference, guiding the creation of BIM models to meet the designated LOD requirements, and it is continuously monitored for compliance.