Difficult, to say the least, to do piecemeal, one trade at a time. It sounds like you'll need to start with removing the ductwork, moisture barrier and insulation, or at least enough to access all of the problem areas. Then correct the plumbing and electrical issues followed by ducts, moisture barrier and insulation. Coordinating the contractors in order to minimize the total project time could also be difficult. Perhaps you could do one section of the crawlspace at a time, starting with the 'virtually unreachable'.

I agree with randy427's overall advice.

Plumbers and electricians often talk very badly of someone else's work (what a hack job!), and they have very little patience when something is hard to reach or the layout is hard to figure out. It is probably pretty bad down there, but maybe not as bad as they have led you to believe.

I think your first repairman should be a competent handyman or general contractor who can go into the crawl space to clean out any debris and junk, and try to figure out what has been done over the years. You need someone who understands plumbing, wiring, and insulation, but you don't really want he/she to fix anything right away. You just need a good assessment of all the work that will be required. It may be a challenge to find that person, since it requires competence in multiple areas.

Once you know what has to be done you need to write out a detailed task list, set priorities, make an initial estimate of the work required for each task, and build a plan/sequence for what should be done in what order. You could hire a GC to figure it all out, but it would be great if you really understood it yourself and could make the decisions about how to get it done.

Bruce

Thank you both so much for the input. Finding someone to give that assessment is such a great idea. I'll have to put my feelers out locally and see if I can find someone with those talents! I love when a handyman or professional will take the time to educate me - I don't just want the work done, I want to understand what is being done! The suggestions on prioritizing and sequencing are so helpful too.

Probably a common story, we had a GC who managed the overall renovation and we trusted him that the crawl space was being brought up to code and was fully accessible (part of buying a old home, we wanted to invest in the bones of the plumbing etc) - it wasn't until after the dust settled (and he and his company were long gone) and we had to go under there ourselves that we realized he wasn't as knowledgeable as he said he was, and didn't do as much work as he told us he did. Hindsight is 20/20 - now I would do things so much differently!!!

Thanks again, and if anyone else out there has additional advice I'll be glad to take it!

I'd get it all assessed and planned as described and then you might be able to tear everything out at once and reconstruct one utility at a time. As long as there was an organized plan for what goes where. Kind of like they do on This Old House. Seems like a GC with experience with old house renovation would be good. And do it in moderate spring or fall weather when you're OK with having things turned off for a few days/weeks.

Thanks! Sounds like I need to watch a few episodes of This Old House. I talked with someone from a crawl space waterproofing company who actually gave me very similar advice. Now to find a contractor who actually has experience with old homes! I appreciate it!