The full form of rfa is Revit Family file.

.rfa is a Revit Family File.  The Revit Family File is stored in the RFA format and is affixed with the RFA extension, and is used by Revit. These RFA files are generally classified as data files that contain one or more 3D models that can be imported into a three dimensional scene and were created and saved using the Revit Family Editor. RFA files contain BIM (Building Information Modeling) data and require Autodesk Revit software. These files are also known as Autodesk Revit file. The Autodesk Revit software is used by architects and engineers to design and model. The Revit model is based on a compilation of items called families. The compiled items refer to the parametric objects such as 3D building objects and two dimensional drafting objects. Autodesk Revit Architecture 2013, Autodesk Revit Structure 2013, Autodesk Revit MEP 2013 software can be used in Microsoft Windows based systems to access and read RFA files.

Launch a .rfa file, or any other file on your PC, by double-clicking it. If your file associations are set up correctly, the application that’s meant to open your .rfa file will open it. It’s possible you may need to download or purchase the correct application. It’s also possible that you have the correct application on your PC, but .rfa files aren’t yet associated with it. In this case, when you try to open a .rfa file, you can tell Windows which application is the correct one for that file. From then on, opening a  .rfa file will open the correct application.

It’s used on Computing ,File Extensions in Worldwide