phasing roof slabs?

[vanderloo5]

Is there a way to phase only parts of a roof in Revit 2015?
My remodel project will require removal of about a third of the existing roof to allow for an expansion. I have a feeling the answer to this is no, as there is no way I'm aware of to separate roof parts in a selection outside of edit mode. But I thought it wouldn't hurt to ask.

[PijPiwo]

You’re right, the answer is no. You need to model two roofs in the existing phase– to demo and to remain. If you already have your roof modeled, copy the roof to clipboard, edit its footprint, paste the other roof from clipboard (aligned to the same place) and repeat the edit, so you have one roof to remain and one to be demolished.