I do a fair amount of traveling through West Virginia and other Appalachian destinations and I have noticed a number of pedestal houses (that stand on concrete piers, wooden posts or a combination of the two), most of them looking like 2nd homes or cabins.
My initial confusion is, having installed water supply into my detached shed and having to dig 3 ft to reach below the frost line so the pipe doesn't freeze in the winter and having a frost hydrant inside the shed to turn water on/off down below so that no water remains in the frost accessible areas, how is this problem solved with pedestal homes? I mean, if the whole house sits on posts, and the water supply plumbing comes from the ground, then the section of the pipe between the ground and where it enters the house is unheated and could freeze no matter how much insulation you wrap around it.
For regular homes that sit on a slab, assuming the inside is always heated and above freezing temps, the pipe goes in from under the frost line straight into the heated area, i.e. it is never exposed to the cold, unlike is the case with pedestal homes.