We moved to the Phoenix area from Michigan about 4 year ago. No basements in this climate is just plain nuts. So the builders (most of whom know virtually nothing about basic physics, construction materials and engineering) whine about costs and how difficult it is for them to build basements because of the difficult soil conditions - as they put it. But miraculously, builders can find that easy-to-dig-in dirt and dig basement sized holes in the ground for swimming pools, the deep ends of many being much deeper than a regular basement would need to be.
Think how much more comfortable a house in this region would be if it had a basement the same shape as the basic plan footprint. Its not exactly a new idea. For the past few thousand years of inhabiting this desert region, large and small basement-type structures were built; not to store stuff but to help keep structures cool during the heat of the summer.
So...the next time a builder tells you that basements just can't be down this way, tell him or her to think again, do their homework, sharpen their pencils and think "swimming pool" only this time make it the shape of the ground floor plan instead of those curvy kidney shaped holes they regularly and enthusiastically excavate.