A little known feature in Revit 2011 is the ability to load an entire Revit project to another project as a group.

On the HOME tab of the ribbon “hidden” under the Model Group icon is the Load as Group into Open Projects command.  This allows you to directly export your current open project into another open project.

Most likely this command would be used after you Save a group out of Revit into a standard group library. This is done by finding the Group under the Project Browser, selecting it, right clicking on this title & selecting “Save Group” from the menu.

In short: standard room arrangements, elevator assemblies, stairwells, etc could be exported out as Model Groups and used in other projects. The Load as Group command is another fast way to load these exported groups into your open projects.