Because we live off the grid, energy and water efficiency are a priority. We have thus designed the house to use as much natural heating and cooling as possible.
First of all, the insulation helps keep the inside temperature constant. For example, when it rains at night here, the temperature outside can drop 20 degrees, while inside it will only drop 3 degrees.
Secondly, we have built eaves on the south side that allow sun to enter the back of the room in winter, when the sun is low and the warmth is needed. However, in summer, when it's hot and the sun is high in the sky, no sun comes into the room. Seeing as most of the south side of the house is window (all double-glazed), this will significantly help our temperatures. The excessive windows also help with minimizing the need for turning on lights. Even on a super cloudy day, no light is needed.
Thirdly, we have buried the north wall of the house up to about 5 feet. This is where the kids' rooms will be, up a flight of 8 stairs. The buried wall has incredible thermal mass, thereby helping to keep the interior temperature constant.
Fourthly, before filling in the dirt on the north side of the house, we buried pipes that loop from the living room to the kitchen. Because the temperature underground remains pretty much constant year round (like in a cave), they will be much cooler than ambient summer temperature and even warmer than a cold winter's day. We can put a small DC fan on one end, and cool air will come out the other, making it an extremely energy efficient air conditioning. Furthermore, we will be installing ceiling fans in a couple of the rooms, for any super hot, still days.
Fifthly, when we lay the brick floors, we will be putting pipes under the brick, whose water will be heated by solar water heaters that we are going to install on the south side above the kitchen. This will also be our source of hot water for the kitchen and bathroom.
We haven't yet seen a winter in this house, but we are very happy with how it performs in summer.
