I beg to differ with some opinions out here about engineers doing their drafting.
1. When an engineer does his own drafting, he spends up to 70% of his time drafting and 30% on engineering.
2. you can QC yourself up to a point, there are more mistakes when an engineer does his own drafting than when done by drafter. Reason, you concentrate on commands, on lines, not on engineering, the result is that the engineering sucks. Big mistakes due to human errors occur. I know it about myself, I make mistakes that I do not do when someone else does the drafting. Look at your own drawing 2 days later and you find mistakes, not just drafting mistakes, engineering mistakes, because your mind was somewhere else.
3. There were some darn good drafters in the industry that caught quiet a few engineers mistakes, especially coordination with structural (HVAC world here)
4. After 10 years, an engineer doing his own drafting cannot possibly state that he has 10-years experience, he has only 4 years of engineering experience and 6 years of drafting experience i.e. 6-years of screen time.
5. Drafters are expert at CAD/revit, engineers only know enough. Work is done much faster. I think every MEP firm could use one or two drafter per discipline (say 2 Mech, 2 Elect, 1 Plumb) and come out on top for everyone, CAD guys makes a living and MEP firm gets work done.
And.. drafters are cheaper, much cheaper.
Same thing happens when you try to manage and design a project at the same time. Both management and engineering suffer.