The following describes a typical workflow for an architect and a mechanical engineer collaborating on a project:
All building geometry is defined in the Revit Architecture project. The project may include rooms defined by room-bounding elements and room separation lines.
See Linking Revit Models.
This step ensures that the Revit MEP project recognizes room-bounding elements in the Revit Architecture project. See Using Room Boundaries in a Linked Model.
The spaces use the room boundaries defined by the Revit Architecture project.
As an alternative, teams can create a Revit project and enable worksharing. The architect and the mechanical engineer each use separate worksets. See Working in a Team.