At risk of drifting off-topic from tractors to construction...
I built my home two years ago using insulated concrete forms for all exterior walls up to the eaves. When we lost power for over 24 hours last winter, with temperatures around zero at night and into the teens during the day, we only lost ten degrees inside the house itself. People in standard stick-built homes lost twenty to thirty degrees. We were still snug and comfortable while others were dealing with frozen pipes. The thermal mass of six inches of concrete combined with the two layers of foam did the trick. Our walls are over 13 inches thick total from interior paint to exterior stucco.