By: Don Rudder
Working on large Revit projects with many consultants can be challenging, but getting all of the model coordinates synchronized across your project doesn’t have to be. With model-based coordination and clash detection becoming standard for every project, it is important that everything lines up between all design models. If the models don’t properly align and share consistent coordinates, moving them around manually in your composite model can lead to errors and unnecessary risk.
One model in the project should be used to manage the coordinate system for the project. This model should contain the accurate, real world, true north rotation and control any specific benchmarks locations, if necessary. All other models will then acquire coordinates from this “master” model. It is typical for the main architectural model to serve as the shared coordinate master. The name of the model designated as the project’s master model should be clearly communicated and coordinated with your project’s BIM team so everyone acquires their coordinates from the correct model.
There are a number of workflows people use for coordinating shared coordinate systems in Revit, some of which can lead to inconsistencies. The workflow described below is by far the most consistent and simplest to perform and will absolutely fix any coordinates issues for your models.
If one of your sub-consultants acquire coordinates from your master coordinate model, there is no guarantee that everything will line up perfectly. There is still a chance that linking in a model that acquired coordinates from a master model will not line up exactly with the master coordinate model. Whatever you do, don’t move all of the elements in the sub model, as that could be destructive and cause unwanted side effects. There is definitely a better way!
Fixing Revit shared coordinates issues can be handled by following this step-by-step procedure:
1. In Revit, open the master coordinate model detached.
2. Remove all Revit links from the master coordinate model.
3. Link in the model that needs coordinates verified/adjusted.
4. Use the move tool and reposition the linked model instance using the alignment tool in X and Y directions, being careful to position the linked model exactly where it needs to be with the master coordinate model. Move the linked model in the Z direction from a section or elevation view, if necessary.
5. If prompted to save the shared coordinates back to the linked model, click “Save Now.” This will actually update the linked model file’s coordinates and save the changes to that model.
6. If you did not get prompted to save the shared coordinates back to the linked model as illustrated in step 5 above, select the linked instance and choose “Publish Coordinates” from the “Coordinates” button on the “Manage” tab of the Revit ribbon.
Your coordinates are now aligned and should align perfectly when linked into other models on the project using the “Shared Coordinates” option in Revit. Repeat this process for any models needing their coordinates fixed.
Don Rudder is STG Design’s firm-wide BIM Manager. He oversees company-wide BIM training sessions and is tightly integrated into every project. Don has over 20 years of experience in the AEC industry and has been working in architecture since 2009. He is a recognized industry leader on the Revit Application Programming Interface (API), a four-time published author on Revit topical training guides, and a regular speaker at several annual conferences including Autodesk University and Revit Technology Conference.
Don will regularly be posting to STG's site about BIM and Revit tips and tricks. Stay tuned!