Do you ever get confused about relying on the BIM model due to its accuracy and efficiency? As a contractor, architect or engineer, have you ever thought about how much you can rely on the data and information provided by the BIM models? If yes, then the answer is very simple for you. The LOD (level of development) in BIM can help you to tell about the efficiency, authenticity and accuracy of data in BIM models. Choosing the right development level can help you deliver projects without errors. In this blog, we will delve into LOD and learn about the levels in detail.
What Does LOD Mean in BIM?
LOD stands for level of development. The data efficiency, competence and correctness in BIM are known by using LOD. Many people confuse LOD with LOI (level of information). They are both different. The level of information is the description of various information available through BIM models. They are further divided as 3D, 4D, 5D, 6D and 7D, which explains the costing, time management, clash detection, sustainable materials, etc. Whereas LOD explains how accurate the components’ specifications and geometry in BIM models are and how much the AEC industry can rely on them.
When was LOD introduced?
The concept of LOD is very old. A construction analysis software company, Vico Software, explain the answer to what is LOD and used it for the first time for a construction project. However, it was officially introduced by the American Institute of Architects in 2008. They define five basic levels for the LOD.
Why LOD is Important in Construction Projects
Construction projects require accuracy in design. Any misinformation or lack of designs can cause huge errors, overspending, and rework. LOD provides authenticity to contractors so that they can rely on the information. It enhances the collaboration among stakeholders, and they can communicate with one another. The BIM LOD reduces the spatial conflicts or missing details for construction project designs. LOD in construction mitigates the risk factors by analyzing the expected results from the BIM model data. Further, these developmental levels also ensure that designs are according to the regulatory compliance of the area. Correct data and efficient design with standard building codes help contractors plan and execute properly for construction projects. In short, from the initial designs to the facility management and post-construction work, LOD levels serve as the basic source of assets.
The Official LOD Framework: Understanding the Levels
The following are the six basic levels of development.
(LOD 100 – Conceptual)
This development level represents the shape and size only. At this level, no detailed information is available. This is a simple model that conveys the design intent only. The elements of this model are represented with symbols and lines and are derived from other model elements. Although no explanatory information is available, but approximate and authentic.
(LOD 200 – Approximate Geometry)
This is one stage advanced than LOD 100. In this model, the elements are explained with quantities, sizes, shapes, and locations. The elements in this model are graphically represented as a generic system. All information obtained from this model is authentic and approximate.
(LOD 300 – Precise Geometry)
This model contains geometric explanations, such as specific shapes and sizes. This model presents the designs and documents for the different sizes and systems. The model elements are represented graphically as a specific system, object, or assembly for different disciplines.
LOD 350
This model contains advanced information than mentioned above. It explains the graphical representation of elements as a specific system, object, or assembly and is used for creating fabrication and construction level documentation and explains the orientation, and interfaces of all the building systems for clashes.
(LOD 400 – Fabrication Ready)
This level generates a model with detailed assemblies, fabrications and connections. At this level, the model explains the installation information for different components as well as the shape, size, geometry, orientation, assemblies and fabrication. We can say that this is the most advanced development level in BIM. Here, the elements as graphically represented as the system and non-graphical elements are also attached for comprehensive information.
(LOD 500 – As-Built)
This is the built-in model with each and every element information including all assemblies, fabrications and installations. This is used as a guide for the post-construction work and facility management. Elements are presented with a graphical explanation, and a non-graphical explanation is also attached.
Applications of LOD in Real-Life BIM Projects
All development levels of BIM are helpful at different stages of construction. From conceptual design to the final analysis, the following are the applications of LOD in BI projects.
Early Design Analysis
LOD 100 is used for the initial design analysis of construction projects. This helps the contractors to make the decisions before investing in the project by analysing of design, spatial elements and solar exposure.
Detailed Design Analysis
LOD 200 and 300 help the engineers and architects in the analysis of final designs and dimensions. They implement this level to make sure that all designs are according to the standard codes.
Documentation And Clash Detection
LOD 350-400 are used for the detailed documentation, including all elements and assemblies. It is helpful for the stakeholders to detect the clashes among various sub-disciplines, such as electrical, mechanical, plumbing, structural, etc. Clash detection and resolving them on time prevent a big loss.
Source For Facility Management
Built-in LOD 500 models are helpful for the construction contractor to use as a source for the facility management and renovation work.
Choosing the Right LOD for Your Project
Choosing the right development level for your project is essential. It is the source of information and a guide to execute the planning in a proper way to deliver on time. Following is the step-by-step guidance for choosing the right LOD as per your project requirements.
1. Selection of BIM Software
The first step is choosing the right software. Some most common BIM software are Autodesk Revit and ArchiCAD. The selection of software directly depends on your skills to use that particular software and the project’s needs.
2. Set Initial LOD And Proceed Gradually
The next step is setting the LOD for your design. Choose LOD 100 for the initial information, and as the project proceeds, you can proceed with the further levels to get a detailed design with all assemblies, fabrications. Installations and geometrical presentations.
3. Team Coordination
Coordinate with your team, and share the designs with all of them. Make sure that all clashes are resolved and the whole team is satisfied with the level of development data and information.
All levels of LOD have benefits in real-world BIM projects. All contractors want that they must have at least LOD 350 for the construction work. However, LOD 100, 200 and 300 are also beneficial due to above mentioned benefits.
LOD and BIM Execution Plans
A well-defined BIM model, along with the LOD selection, conveys the message to all contractors, architects and engineers on how they have to execute their plans. It enhances the sense of responsibility among them and sets the accountability process even after the construction work. The following are the main benefits of executing a BIM plan with a defined LOD phase.
Clarity
BIM plans with a defined stage of LOD clarify the design intent. It reduces the ambiguous points and enhances the efficiency of the design, which is helpful for the smooth workflow.
Standard Information to All Stakeholders
BIM plans provide standard information to all stakeholders and align them to what information will be available at which stage of LOD.
Effective Communication
Well-defined LOD BIM plans detect the clashes and connect all stakeholders on a central model, and then can communicate easily to fix the errors and improve the final design with the solutions of possible clashes.
Guide for Future Modification
LOD-based BIM models have all the information and clarity and are set as a guide for future modifications and reworks.
LOD Standards and Guidelines
To get the maximum benefit after implementation of a specified LOD for your project, it is essential to adhere to the regulatory compliance set by the American Institute of Architects.
Conclusion
LOD-based BIM models are very effective for detailed information and are highly used in the AEC industry for the alignment of accountability, clarity, and consistency in the design for the site work and even after that. These models are a key to the successful completion of a project with clarity, clash detection, a collaborative environment and better communication.
Read This: Construction Estimating Services
FAQS
what is lod?
LOD means level of development. It is the detail of accuracy through BIM elements at different stages of the project.
Which LOD level is mostly required?
Almost 80-90 BIM projects require LOD 350 because it includes sizes, shapes, fabrications, assemblies and documentation for the construction projects.
Which LOD is considered as Built-in Model?
LOD 500 is considered a built-in model and serves as an asset for future work, installations and further modifications and renovations even after the construction work.
