I built as low as I could but plenty high enough. There's a "seasonal" artesian spring that flows for weeks when it gets going, up in the corner I dug out 4' for the driveway and extra parking. None of the house is below grade, and the only areas I dug in were to cut off ground water infiltration under the slabs. I also cut surface drainage on the high side to keep water from the hill diverted. The house is essentially a pole building and I didn't want the pole foundations fluctuating with seasonal ground moisture, so everything uphill got cut off 4' down and the dirt under the house stays bone dry. No need for a basement since the deepest it ever freezes here is a few inches and at that only for a few days.
Speaking of rain, I sure wish some of you would send me some, like about a foot of it at least, maybe two. Spring is trying to spring, oak trees have all put on leaves and flowers, but it hasn't rained any significant amount since last year and everything is dry in a bad, bad way. I'm afraid we're starting into another five-year drought cycle.