Changing the names of rooms, sheets and views in Revit is easy to automate with macros and the API. Renaming is a two step process. First, you gather all the sheets, views, room tags or whatever you want to rename with a collector. Once you have all the objects, you simply loop through the collection and change each object's name parameter. If you're replacing an old name with a new one, you can use a conditional statement to do the swap. The name parameters differ from object type to object type so you'll need to refer to the API documentation (which you can download here) for the exact parameter name.
In this macro, the building names are changed from from "North 1", "North 2", "South 1" and "South 2" to "B1", "B2", "B3" and "B4" respectively. The macros look at each object's name and replaces "North 1" with "B1", "North 2" with "B2" and so on. You can edit the code to use your own building designations. As you'll see, the code is very straightforward.
To get the free Revit Renamer macro, which is part of the ArchSmarter Toolbox, one must subscribe to ArchSmarter's email updates.