Hey Tc I'll have to take you up on the help offer when I get a little closer.
We just built our home. strusehouse.blogspot.com My wife just uploaded some new pics.
We went with polysteel icf's R61 insulation in the attic. I put in radiant floor heat, with the slab in the basement being a heat sink. In the summer I should be able to pump water to the cooler slab and transfer most of my slab heat to the basement. If the heat sink isn't big enough I drilled my well 300ft deeper than needed for water. I will just drop in a bundle of pex pipe and use the well water as a heat sink. This is a great experiment so I will have to see just what % of my cooling can be done this way.
We live in Arizona so we have a great year around sun source. $40,000 should get me very close to net zero.
I am waiting for a couple of utilities bills to know my exact usage.
We put in a Rheem solarhart 80 solar water heater that so far even on these cold days is providing plenty of hot water. Also used the highest reflectivity roof tiles we could get that were affordable.
Wife wanted a gas stove so we do have a propane tank. So I can get close to net zero but not quite 100%
At this point I am going for as much self sufficiency as I can
Anyway its most of the reason i haven't flown AH much in the last year.