Building Information Modelling (BIM) is a digital representation of the physical and functional characteristics of a building or infrastructure asset. BIM is an effective tool for improving collaboration, coordination, and decision-making throughout the project lifecycle. However, BIM is not a single standard or process but rather a combination of several different dimensions and levels of detail (LOD). In this article, we will explore the BIM dimensions and LOD standards in more detail.
BIM Dimensions:
The BIM dimensions refer to the different aspects of a construction project that BIM can be used to represent. There are currently four recognized dimensions of BIM, and they are as follows:
2D: This refers to the basic drawing elements that make up a construction project, such as floor plans, elevations, and sections.
3D: This refers to the creation of a digital model that represents the physical and functional characteristics of a building or infrastructure asset.
4D: This refers to the addition of time as a dimension, allowing for the creation of a construction schedule or timeline.
5D: This refers to the addition of cost as a dimension, allowing for the creation of a cost estimate or budget.
LOD Standards:
The LOD standards refer to the level of detail or development that a BIM model has reached. These standards are used to communicate the level of detail that can be expected from a BIM model at a specific point in time. There are six recognized LOD standards, and they are as follows:
LOD 100: This refers to the concept design stage of a construction project. The model at this stage is very basic and only includes the basic shape and size of the building.
LOD 200: This refers to the schematic design stage of a construction project. The model at this stage includes more detailed information, such as the location of windows and doors.
LOD 300: This refers to the design development stage of a construction project. The model at this stage includes even more detail, such as the location of electrical outlets and plumbing fixtures.
LOD 350: This refers to the construction documentation stage of a construction project. The model at this stage includes all of the information necessary to create construction drawings and specifications.
LOD 400: This refers to the construction stage of a construction project. The model at this stage includes all of the information necessary to construct the building or infrastructure asset.
LOD 500: This refers to the as-built stage of a construction project. The model at this stage includes all of the information necessary to operate and maintain the building or infrastructure asset.
Conclusion:
BIM is a powerful tool that can be used to improve collaboration, coordination, and decision-making throughout the project lifecycle. The different dimensions of BIM, from 2D to 5D, allow for a comprehensive digital representation of a construction project. The LOD standards provide a clear and consistent way to communicate the level of detail or development that a BIM model has reached at a specific point in time. Understanding the BIM dimensions and LOD standards is essential for effective BIM implementation and successful project delivery.
References:
National BIM Standard-United States® (NBIMS-US™) – https://www.nibs.org/page/bsa_nbimsus
AIA G202™-2013, Project Building Information Modeling Protocol Form – https://www.aiacontracts.org/resources/71206-aia-documents-on-demand
PAS 1192-2:2013 – Specification for information management for the capital/delivery phase of construction projects using Building Information Modelling (BIM) –
