Your builder will engage an outside quality assurance person for quality only. The council still do their 4 inspections (foundations, reinforcing, frame and final), but the builders QA guy will most likely do 2 inspections, pre-plaster an final. That is the info I am getting from the volume builders.
You might be right. Don't know about the inspectors builders used, after making some phone calls, even if we use our own private inspectors, they normally only do 2 inspections. That is the best we can find.
So that's 2 inspections from builder side which might not trust so much (they are paid by builder!) and 2 from our side, which hopefully will be at least slightly better. Plus a lot of our own, personal, unprofessional checkings...