Passive solar backup heat?
I'm in the process of designing a passive solar house, what kind of heat would you use for supplemental heating? If I can get to 100% passive solar will I still need supplemental heating to meet codes? I am looking at possibly putting in a masonary heater but will building codes allow me to use heating that isn't automatic (such as a furnace or geothermal)?
The passive solar design I am looking at will have thermal mass and a large amount of south facing glazing that I will have computer controlled exterior rolling insulated shutters. I am looking for input on this idea, any cons to this I might not have thought of?