If it were really smart, I'd have a toilet and shower that uses 1/4 of the amount water, my gas stove would not have a pilot light, and "dumb" motion sensors for light have been around quite a while - but not ubiquitous (more common the EU).
Commercial buildings have had computers driving heating and cooling systems for a couple of decades (without thermostats but with temp sensors) so you don't need internet for that either. And I've never seen a house with VAV's installed in the ducts to actively heat/cool only the occupied portions of the home. And the easiest of all before construction - just "rotate" the foundation towards the sun to take better advantage of passive heating and cooling, that's an easy 15% energy bill savings.