Depending on the climate, they don't have to look too futuristic. Here are a bunch of "passive houses" in Sweden (houses without a dedicated source of heat, ins

Depending on the climate, they don't have to look too futuristic. Here are a bunch of "passive houses" in Sweden (houses without a dedicated source of heat, instead surplus heat from cooking, showering, people etc provide enough heat due to good insulation): http://www.google.se/images?um=1&hl=sv&safe=off&client=firefox-a&rls=org.mozilla%3Asv-SE%3Aofficial&tbs=isch%3A1&sa=1&q=passivhus+site%3A.se&aq=f&aqi=&aql=&oq=&gs_rfai= http://www.google.se/images?um=1&hl=sv&safe=off&...