Copying SheetsYou might think it is not possible to copy and paste sheets between projects. Well, normally it is not, but there are certain situations where it is possible - kind of . . .
In the project browser, if you right-click on a sheet, the option to 'Copy to Clipboard' is normally greyed out
However, if the sheet does not have any model views on it, then 'Copy to Clipboard' is enabled
Once you have copied a sheet to the clipboard, you can go to another project in the same Revit session, and 'Paste from Clipboard'
You can also paste sheets within the same project to create copies of them - it just increments the sheet number and puts a number suffix to the sheet name. If there are any drafting views on the sheet, it will duplicate them and increment a number suffix. This is a quick way to create multiple similar sheets - all you need to do after that is add the model views
Links for Copying ViewsCopying views between Revit projects
Copying contents of 3D views between Projects
Duplicating Views with Linework Overrides (within projects)