Details, Details. What Information Do You Need?

Five basic Levels of Development (LOD) are generally accepted for Revit and 3-D modeling files in the construction industry. They give a bare bones scale of detail present in the model and its components. These are often referred to in construction documents to represent what the owner/design-team/contractor expect at different phases of a project. Let's take a look.

LOD 100 

This level has the least amount of detail and is used at the beginning of the design phase for conceptual drafts. At this level the model has little of the detailed information we expect in a BIM model, and is better described as a three dimensional sketch.

LOD 200 

At this level the model begins to take shape with basic MEP layouts and equipment placement. You can probably print drawings and project cost estimates from the model, but there isn't enough information for coordination and much of the detailed information still needs to be plugged in.

LOD 300

At this point the model is a more accurate representation of what will be constructed, with fixture / equipment placement and hook-ups, pipe/duct/conduit runs in place, and information included for key components. BIM Coordination can begin, product data can be submitted and approved, conflict resolution and QE changes can be made, and shop drawings  incorporated.

LOD 400 

This could be called the Building Model. Coordination is complete. Approved materials are represented and manufacturer data is linked to fixtures / equipment. Shop drawings and details are modeled and available for fabrication. The model is no longer conceptual. It is a virtual replica of what is to be built. Fab shops can pull out spool drawings and tradesmen can work to the model.

LOD 500

The highest level of detail represents the project "As-Built" and includes all engineering and O&M data necessary to manage and maintain the facility and equipment. The model has been tweaked to include any changes made during construction. Fixture, equipment, and material families contain all data needed by the owner going forward. This includes panel labels, valve charts, flow settings, and any other information requested by the owner in the contract.

But even at LOD 500 the model isn't "finished". BIM models are fluid and can be tweaked, added to, and changed by the owner as the building itself changes. Owners can note repairs, replacements, additions and keep their model up to date.

These levels are not always strictly adhered to. Construction may begin with a model at LOD 200 and the owner may only require an "As-Built" model of LOD 300. But in a perfect world the development of a BIM model would follow this path. Contractors can reasonably expect a model of at least LOD 200  to bid from and begin coordination, but that isn't always the case. In some instances the A/E may manage the model throughout the development, and in others the contractor may be called on to detail the model.

So, where do we get all of this information and when do we plug it all it. It does make a difference and unless you want to do everything twice -- or three times -- you want to work toward the correct level of detail and follow a logical workflow. In my next post I'll walk through a suggested workflow to take a model from LOD 100 to LOD 500 with a minimal amount of backtracking and editing.

Until then I'll leave you with a video from SysQue on what they can add to Revit. This isn't an endorsement, I'm just sharing. I'll dig more into it and post a review in the future. For now, enjoy the video and the potential for your BIM. And let me know what you think. Comment below or drop me an EMAIL.