"Let alone technically possible?" Most of MEP work is laying out pipes and wires so that the fixtures such as airvents, electric sockets and so on get connecte

"Let alone technically possible?" Most of MEP work is laying out pipes and wires so that the fixtures such as airvents, electric sockets and so on get connected to the system. The MEP contractor's task (overly simplifying) is to punch holes into walls and drag their spans of pipes and whatnot through them. The designs' intent is to specify the fixtures, and how the perform (airflow etc). The subcontractor basically promises that they make those fixtures do their job - and not that their wiring and whatnot follows any specific plan necessarily. Modern digital workflows are getting slowly integrated to the process and they may improve the productivity and quality in long term.