We forget that things have to be done differently in the cold country! For a 30" high stone wall, 3' of dirt was dug out for footers to support the wall. And even for our small house, it took two full loads of concrete to fill these holes. Additionally, re bar was embedded into the concrete for additional support. The goal, of course, is to prevent the stone wall from heaving in the frost.
The great news of this stage of the work is that new sewer and water pipes were installed since the existing ones were original to the house (or at least original to the date that these services were provided by the city.) Insulating styrofoam was wrapped around the water supply pipe to add additional protection from frost.