You have to be crefull what you call a bsic install, last month we go to a home, open the fixture, and find all the wires rotted to the hickey clip. lath and plaster. The guy spent 6 hours there replacing the wiring and installind a support box, then assy the customer fan with light missing parts.
The word standard usually, does not exist in old work jobs, even in a clean wall board job, you can run into problems, like the lady that had boxes piled up from floor to ceiling, and tanted the fan in the center of the bed.
Each job has to be looked at on it's own conditions, for all old work.