So sweet seeing them build the frame on the ground and flip it Up

I just went through a water heater replacement, and considered on-demand electric. I would *strongly* recommend *against* it, *especially* if you're in Pennsylvania (which is what I assume your mention of 'PA' referred to). The inlet temperature that you get in the winter means you will need to have an *enormous* unit to supply hot water to a house of this size, something like a 36kW model is only rated at 3.7gpm at a 65 degree rise. When your inlet temperatures gets into the 40s in the winter, that is potentially even lower. Then there's the draw; that 36kW unit is running 4x40A double-pole breakers that can *easily* consume a huge chunk of your panel budget on standard 200A home service -- with that 65+ degree rise in the winter, it'll be running basically full tilt to supply a standard flow shower + a hand sink -- add in other electrification like an induction stove, heat-pump based HVAC, a L2 EV charger... Unless you've got 300 or even 400A service, you're likely going to be stretched thin at best, and even if you've got the panel capacity the flow at 65 delta is... rough. f you want on-demand, I would look into gas. Otherwise, the obvious ecological option is a heat pump electric -- the recovery time isn't as good, so you may need to oversize on capacity as your family grows, or have a supplemental storage tank, but hey. Note that interior-drawing ASHP water heaters will have a volumetric requirement for the room they're in, so make sure that is met; otherwise, there *are* exterior unit models. That said, maybe I've completely mis-judged your situation, I'm just a stranger on the Internet. Just my 2c.