There is sorta such a thing today. It’s called HERS. 100 is a “normal” house. 0 is a “net zero energy” house. And negative means you have even more PVs than you need. Nice. Someday websites like realtor.com, redfin.com, etc. will let you search on such things.
The best house I’ve seen is this -33 HERS of Carolyn and Kyle Cave in Hadley, MA. It’s also nice to know what a house is pre-PV to get an idea of how efficient the house and it’s occupants are. Oh, and a house in Maynard MA is -8 HERS.
Anyway, good work Caves! Your house follows the important rule of thumb I now encourage people to use — Build (or pick) your house with a lot of good roof space for PVs. Small footprint houses like ours are a little more efficient, but we don’t have nearly as much room for PVs. Dumb.
(Oh, and our house is nearly 0 HERS. I am not exactly sure what — I forgot to ask for the pre-PV score and if I recall correctly the PV offset used the wrong KW total.)
(Oh, and read about the limitations of HERS at the link at top…)