How can I copy a Legend from one Revit project to another?

Simply Copy and Paste!

Revit includes a couple of tools for transferring content from one project to another, but none of them work with Revit legends.  The “Transfer project standards” tool does not allow you to transfer a legend view.  The “Insert From File > Insert Views From File” tool does not work with legends. So, the simple answer is to copy and paste.  Here is the process.

Step 1 – Setup

Create a blank legend in the project you want to copy into. Name it appropriately.

Ensure this is the same scale as the previous legend.

Step 2 – Open BOTH Projects in the Same Revit session.

Open the legend you want to copy FROM

Select all the elements from the legend and Copy to the clipboard (Ctrl+C or icon on the ribbon)

Switch to the legend you want to paste TO.

Paste the elements and place them anywhere on this view.

NOTES

Any families in your legends will be copied into the other project. If those families already existed, they will not be updated and the already in your project will be used.  (This in some cases will overwrite the elements that previously exist if they are named the same.)