Autodesk has provided us with the REVIT Building Maker tools to convert Mass Object faces to Walls, Roofs, Curtain Systems and Floors.........and maintain associativity.
The key is we have to make sure the Mass Object Family is of the Family Category > 'Mass'.
You can maintain two seperate 3D views to manage the Mass object and the new Building Components simultaneously. You can change or alter the Mass object and 'Remake' the building components and watch the model update instantly. It's like magic.
Below is a link to a great CADclip explaining how to use the 'Building Maker' tools.