Automatic Revit Legend Creation

Creating legends in Revit could be a very annoying task. There is also a high risk of human error. The idea of a legend is to explain elements visible in certain views when both placed on sheets. So one option could be to create universal legends for your needs. But this means that some legends will be very long and fill with unneeded information, just because of the fact that the elements included in the legend will not always be visible in all views. This leads us to the second option – custom legends. We can use some sort of legend template with all elements listed and start deleting the ones that we don’t need. Not a bad workflow but a high-risk of human error. 

Unfortunately, Revit doesn’t have some sort of automatic legend based on what is visible in a certain view. That will be a great feature in the future. To solve this problem now we were asked to create a custom tool. All the information is there – Revit knows what is visible and what is not. So theoretically it should be easy to create the legend based on that. Of course, there is no easy job.

First of all Revit API doesn’t have a method for legend creation. This means that you need to have a placeholder legend or sample legend to start from. Doing that we started with a sample legend with one legend component. The idea was to extract the information from the model views and modify the legend based on this information. Modification means that we copy and change legend components while also drawing line by line the whole table. Fortunately, our client has a good Revit template and has good views organization using a naming convention. Using the logic from the names of the floor, ceiling plans and legends we built the tool.

It matches the legend with the view series. That is how we are able to create legends custom tailored for each project and use case. This workflow increased the quality of the projects and eliminates errors. Following the naming convention and company standards are essential for workflows like this to work properly. So if you want to increase your productivity and reduce errors start first with building and maintaining well your company standards. After that creating custom tools will be a much easier task.