A fascinating article here at Physorg on American versions of German “passive houses” – houses that maintain a comfortable temperature in cold climates without the need for active heating systems:
Because there is no furnace, the rooms are quiet. The only sound in the kitchen is the hum of a refrigerator, which along with other appliances, helps supply heat to the airtight 2,300-square-foot Batavia, Ill., home.
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Katrin Klingenberg, founder of the institute in Urbana, Ill., said that typically, passive-house owners use 10 percent of the energy used in a standard home.
More info on passive housing can be found here.