Almost at every Revit project you will have to deal with links. In order to adopt a good linking strategy you need to have in mind several things.
At first you need to get familiar with positioning options. There are four of them, and they are closely related to three Revit’s origin points: Internal Origin point, Project Base Point, and Survey Point. For more information on these origin points see Revit tip #7 (Configure the coordinate origin points in Revit). You can link Revit models in relation to these origin points (there is an option for each origin point), or in relation to the center of the geometry.
- Center to Center. This linking option is not related to origin points but to model geometry. So it is geometric center of your models. Revit finds the center of a bounding box around the geometry in both host model and linked model. This option is suitable when you want just to import a model and then position it manually. It is not suitable when you work on a large project with many links. This linking option is available for both RVT and DWG links.
- Internal Origin to Internal Origin. The Internal Origin in the linked model is placed at the Internal Origin of the host model. The Internal Origin point is a fixed point in Revit files. You cannot select or move this point, you can just see it if its visibility is turned on in VG (Model Categories -> Site -> Internal Origin). This option is suitable for small Revit projects where grids in all models are placed in relation to the Internal Origin point, and the geometry is modeled accordingly. You can use this linking option for DWG links as “Origin to Internal Origin”.
- Avoid far distances. Revit cannot use this option if the distance of the geometry in the linked model is more than 20 miles (32 kilometers) from the internal origin. In that case you need to use Center to Center or other linking option.
- By Shared Coordinates. This linking option is related to Survey Point. It is available for both RVT and DWG links. This is the most convenient linking option for large projects with many links. But also it is the most confusing option for the most of the new Revit users. To link “By Shared Coordinates” you firstly need to share coordinates between files.
- Use reference model as “single source of truth”. The good practice is to have one Revit file which is a “single source of truth” and which can be used for obtaining shared coordinates in all models of the project. Use “Specify Coordinates at Point” command (Manage – Coordinates – Specify Coordinates at Point) to configure coordinates in that reference file using survey CAD file. You can also acquire coordinates from survey CAD file (Manage -> Coordinates -> Acquire Coordinates). Then link the reference file into all models of the project (using other linking option such as “Internal Origin to Internal Origin”), move it into place, and acquire coordinates from it. After that, all Revit models can be linked to each other using “By Shared Coordinates” option. For DWG files, you need to link them into reference file (using “Center to Center” or “Origin to Internal Origin” option), manually move into place, then publish coordinates to them (Manage -> Coordinates -> Publish Coordinates).
- Project Base Point to Project Base Point. Project Base Point in the linked model is placed at the Project Base Point of the host model. This linking option is not available for DWG files as they don’t have Project Base Point.
- Move to Internal Origin. By default, Project Base Point is placed at the Internal Origin and it is recommended to keep it there. If you moved it, you can use “Move to Internal Origin” command (right click on the point -> Move to Internal Origin) to move it back. Take into account that alignments in the copy-paste function is performed in relation to the Internal Origin.
