I had mine built while having an addition to the home built. I've acted as my own GC on both accounts. For the addition, I hired out the concrete, framing, roofing (TPO so didn't want to try that on my own), electrical, mech, and plumbing (can't do those as a homeowner here). For the house, electrical, mech, plumbing, etc... are doing complete jobs. For the garage, I had them do the bare bones - concrete, frame the structure, roof it, and put in minimal electrical just to satisfy the permit. Once I complete the addition (hopefully soon! I'm getting worn out!), then I'll go in and do up the garage properly myself. As for on time, most of my subs have done a pretty good job keeping up with my schedule. The garage was certainly done on time but we've had a few delays on the addition but it's all good.