An 1150 SF residence floor over a similar size lower level built partly into the hill on the North. Exterior walls are constructed using Insulated Concrete Forms (ICF). A system of radiant heating tubing is embedded in both concrete floors. Solar hot water is furnished by the collectors on the roof for both space heating and domestic hot water. During the winter Passive Solar sunlight charges the second floor concrete slab during the day and the slab radiates its heat to the space when the temperature in the space cools down. This system will cut utility costs by more than half.