Does all electrical work need to be done by an electrician?
It depends entirely on your municipality. Once you decide where to build, call the local inspector. I built my house 5 years ago. The meter socket and feed from the socket to the panel had to be done by a licensed electrician. I did the rest of the wiring myself. It had to be inspected at both rough and finish stages, of course, but there was no problem with me doing it myself. As part of the installation, I put a subpanel in my shop, and that was also approved. As far as things installed by someone else and inspected, where to begin? For mechanicals, the HVAC and plumbing must be inspected, and are generally subbed out to licensed pros. Everything else, from footings to framing to insulation to finish are inspected. Call the local inspector, and he/she will give you a list of inspections needed. Hope this helps.