General contractors attempt to solve coordination problems between MEP and drywall trades by identifying priority walls that should be framed and topped down prior to installation of MEP work.
In the mind of general contractors, a priority wall for the most part is a full height wall that would be nearly impossible to frame, from top to down and caulk after mechanical work is in place. In the mind of MEP contractors, a priority wall is a wall where as much MEP work is installed while still making it possible for the drywall contractor to install his work. In the mind of a drywall contractor, a priority wall is a wall that is installed prior to MEP work.