I can't believe I missed this. Finally, a way to have backwards compatibility with all of the Revit users who don't want to pay for subsciption and be on the latest version.
Source: http://autodesk-revit.blogspot.com/2011/04/saveas-older-version-of-revit.html Revit: Saveas an older version of Revit
Ok, so this has been a long standing request by many a Revit user, the ability to “saveas” to an older version of Revit. How many times have you heard users say that they have opened a Revit file in the wrong version and saved? or that the partnering consultant you are working with can’t open the latest version of your file because they are still on Revit 2009?
Well maybe this might be the answer…I got an insider track the other day from Steve Goutcha of Pillaroof Architecture. They have a couple of inside API guys who are working on tool which will allow you to migrate the Revit database to an older version. To good to be true? Well I exchanged mails with Steve……“as users of Revit ourselves, we understand the issues that many Revit users have; the ability to do a saveas to an older version seems to be a high priority and this seems even more important as the adoption of Revit grows. If you think about it, you have been able to this in AutoCAD or ACA for years. We have been able to get under the bonnet of the Revit API and our tool allows us to save back as far as Revit 2009. Obviously each release of Revit includes new functionality so our tool will convert newer Revit elements into generic models. You won’t be able to edit these objects because effectively they are embedded IFC components, but this should be a great step forward”…..Want to know more? Be sure to check out Steves website for more details.