[Porchdog]

Have any Mennonites or Amish nearby? It might be worth a half a day to go talk to some of them about the problem . They dominate the market for that kind of work around here.

The geotechnical advice is probably good. Those guys could be able to recommend contractors as well.

We have dealt with foundation subsidence /repair here with our customers a few times. I am a fan of micropiles for substandard soil issues.

Assuming that you don't have a soil issue I would see your problem as pretty straightforward.

When I was in my young teens my father, brothers and I did essentially the same thing on three different structures - an old farmhouse (pointed loose stone foundation in a flood zone), the adjacent barn (substandard "concrete" footers in the same flood zone) and a vacation cottage (the cottage was on footers, Dad wanted a basement).

Our process was strictly farm engineering. We either jacked the structure with lolly columns or with bottle jacks and timbers, we excavated (by hand) 4' - 8' sections for footers and we formed and poured concrete walls. We did the whole cottage section by section with a total of 10 or so pours. The farmhouse we did one whole wall and a staircase and we encase the other walls. The barn we did one corner and another section of wall.

This process was a ton of hard manual labor. We didn't know any better. None of those buildings have subsided since.