Hmm.... I never thought of that. I did notice that some cheap, crappy developments out toward Bridgeville didn't have them, and predictably, those homes have way too many cracks for their age. I also heard an offhand remark a few weeks ago by someone that "most homes in X neighborhood don't have basements" (they absolutely do, indicating that the speaker was in a different social class than me and was probably looking at far newer homes that I could never afford). Now, new buildings being out of compliance with basic codes is very common... inevitable, even, but surely oversights THAT big don't happen, right?

It turns out there are actually FOUR methods for frost protection:

1. Founding below the frost depth.
2. Extending insulation into the ground, such that the heat of the building will keep the ground under it from freezing.
3. Building Per ASCE 32
4. Founding on solid rock

Now, #3 would probably require involving an engineer, so I doubt it's done for cheapo houses, and #4 would be absurdly expensive, so I assume that #2 is the normal practice.

With that being said, many types of insulation degrade with time, and #2 involves a pinky promise to keep the house at 64 degrees minimum year-round. So, I guess look for newer houses to occasionally get f***ed when they're vacant/for sale in the winter or there's just a winter power outage.

FYI: Crawl spaces don't help with frost protection. The don't affect the foundation depth, they just raise the living area off the ground. They're so that the plumbing under your house is accessible for repairs instead of being encased in a solid concrete slab. Like a basement, but cheaper.