The Passivhaus method was influenced by the Saskatchewan Conservation house project. Quoting from http://esask.uregina.ca/entry/energy-efficient_houses.html :
> It had no furnace; instead, the house was heated with a solar heating system designed specifically for Saskatchewan’s extreme Climate.
Hey, sure, tell that to everyone in the northern states, no need for heat right? I mean when it's 10°F outside you can just shut the windows and be nice and warm, right?