@mitchconner If I had a tiny house, I'd do 12v LED for lighting, probably a parabolic skylight for maximum comfy and cost, and a rocket mass heater with the foundation serving as a thermal mass. Wiring would be cheap because it's a small homr, and you could go solar easily when using 12v. Ductless mini split would be the way to go to keep HVAC simple and not waste space. Plumbing would be a matter of joining the bathroom wall with the kitchen and dumping the sink water into the the same septic. You'd be surprised how little water you have to use if you're trying to conserve it. I'd likely do a shallow well and septic with pumps for both if I could get the land in a good place like southern WV or East TN.