Designing and then building a passive solar home requires careful calculations based on the exact location on the globe and an exact north/south line on the building site. Dropping a due north/south centerline in Autocad is easy. Dropping a due north/south centerline on the earth is a whole other matter that requires a familiarity with astronomy and a good view of the North Star. A compass will get you the general direction of north but not true north. It is essential to have a passive home aligned to true north and thereby aligned to the sun's seasonally changing azimuth and altitude throughout the year. If the north/south line is off then you could create too much or too little heat in the house. Alignment should be done with the care of a well tuned sundial. So, day one in construction actually started on a dark moonless night the night before day one. I had a general location for the house's centerline established on the property where I wanted it. In order to get the specific centerline, I placed a tall pole at the northern end of my would-be line. Backing up from that pole to the southern end of the soon-to-be line, I set my second pole in line with the first so that the North start disappeared behind them both thereby establishing a true North/South line based on the earth's axis not it's magnetic pole. I chalked out the rest of the house's outline from there and then set to some back hoeing. To me that backhoe was a chisel and our property was a piece of marble. I was sculpting...with a tractor!
