Houston is blessed with high clay content soil and cyclical drought conditions which makes for a ruff life as a foundation. Constant soil swelling and contraction from variable moisture means that pretty much all new construction in town is carried out with post tension slabs. Custom homes like this will spring for the extra expense pillars.
Dave this is just a tease, you need to upload the pictures post aqua scapeing. He did an an incredible job on setting up the rock stack. The pictures don't even do it justice, I will let him chime in on how he pulled it together. Also upload a pic of that skimmer and sump on the pallet, that will make a few jaws drop.