Guest post by Paul Mittig
I built my 10 x 20 house in 2005 for about $10,000 in materials, including all furnishings. It is built on six poles set two feet into the ground, that support the floor and roof. There is no framing in the walls except at the door and the large window. The walls are rigid foam insulation, R21, covered with ½ inch sheetrock and all glued together. The ceiling has R38 fiberglass insulation, and the floor has R19 fiberglass insulation. I spend about $100 a year on propane for heating, cooking, and water heating.
The house is located in the hills of Northern California. I live in it full time. The house is set up for one person, but you could easily put a double bed by the door where the tall bookcase stands. If you did this you might want to move the window.
I have a three way RV under counter refrigerator, that I run on electricity. For hot water I have a heat before use RV water heater, turn on for 15 – 20 minutes then turn off, it generates enough hot water for a shower and runs on propane. The hot water heater is located under the bathroom sink.
I would have liked an on demand water heater, but I have no place for the flue as an oak tree entirely covers the roof. However, the tree shades the roof from the sun in the summer. The winter sun comes directly into the 4 x 7 window. If there is any sun at all I don’t need heating no matter how cold it is outside.
I had a composting toilet, but it didn’t compost well and was a gigantic hassle. I replaced it with a portable toilet that I empty into the septic system and clean out at my sister’s (who lives nearby) once a week.
There are two things I would change: First, I would install triple pane rather than double pane windows. When it gets below 40 degrees at night I put 1.5 inch rigid insulation panels over the window on the inside after dark. It helps. The second change would be to add rigid foam insulation to the roof, R38 is not enough.
Thank you Paul for sharing your unique little home with us.