Site Ground Temperature is not used by my models to calculate ground heat transfer. This is because my models use Foundation Kiva instead of some other algorithm. If I look at the wall/floor surface boundary conditions, they are "Foundation," and the boundary condition object is a Foundation Kiva object.

Instead of playing with Kiva settings to try to minimize ground heat transfer, I am instead adapting a measure to change the boundary condition for surfaces with "Foundation" boundary conditions to "Adiabatic."

This should hopefully result in zero conduction between the building and the ground.