My understanding is that a homeowner acting as owner-builder isn't necessarily doing all the work physically themselves, though they certainly could be. I believe the owner-builder designation just means there's not a contractor on the hook for the permit and subject to Contractor's License Law and that the homeowner is taking on all liability. That's my understanding for California anyway.
I was acting as owner-builder when I recently obtained a permit for my laundry room remodel (as discussed over
in this thread). In doing so, the City required I fill out the attached form and certify that one the following statements applied to me:
Or...
In my case, option #2 applied but I could have certified as owner-builder under #1 if I'd planned on doing all the work myself. I can definitely understand
@Ir3th0283's point about requiring the homeowner and/or their employees to be licensed/certified to perform electrical, plumbing and mechanical work if the homeowner wants to be permitted under #1. That would certainly seem safer than the status quo.