Once upon there was a time a energy efficient housing. It was a geothermal heating. The cost it had was more large for giving to a house of big age. A fresh house of being a new building it was easier because no workers are have to be paid to demolish a structure or a fitting or a finishing to retrofit. The plan future of a new house is seen at the start, with a idea that geothermal system is a installation to have. As well, there are two kinds of ways to have installation in the ground. One is horizontal and two is vertical. Horizontal is a more cheap type in that it is trenches dug by excavators 6 or 8 feet under surface soil so it is cheap. Vertical is more expensive in that it is a auger digs tall holes very deep over a hundred feet. Both types have hundreds of footage copper or plastic pipes called earth loops. The ground deeper than the line of frost is more stable of temperature than air on top of soil. This stable of temperature is transfer to pipes that are water or antifreeze and water filled. The liquid inside the pipes is pumped into a house with geothermal heat pump system having installed. In like a reverse refrigerator, the difference of heated temperature is remove from pipes and spread through house in under floor heat or baseboard heaters or fan blows through ducts of new installed or retrofit. The comfort feels better of the heat because it is upward moving like heat does naturally. It is different than a force air system when heat gathers on top of the ceiling. A person with the geothermal installation can save large money. Almost zero fuel using cost except electricity a little bit. Good for a wallet and good for Earth planet because no greenhouse gas. A families wants to save large money, he might have to give a amount of money at the start. But to help the world a good wallet is wanted.