State of the art would be quality passive solar design, Sips
construction with R 80 ceiling, Insulated foundation and under basement
floor. Tri pane glass LowEargon, high solar heat gain glass SHG, with
proper sun in summer permanent awnings, even an insulating foam core
auto exterior closing shutter panel system. Insulated curtains with
cellular shadees in tracks. Window R value closed could be R 40.
A combination of heat sources depending on what you could afford ,
Solar- wind powered, Geothermal heat pump radiant floor heat with AC and
Ng or propane backup Heating costs could on a pay basis be 1/20 th of
normal houses, a key point in keeping expensive costing heat and energy
options down. AC you would have forced air so Ac additional is cheap, A
VS DC blower would run on humidistat for days when humidity removal is
only important. Its all standard equipment, just pick it right.