Well heres the thing. Dad and grandpa owned an insulating business in the late 70's. The whole home was insulated with urea-formaldahyde foam, which pulls about an r value of 4.5 per inch, so the walls average about r27 on the low side, which I think r13 is required. Secondly he had double hung double pane vinyl windows with triple track storms installed. The attic has very little insulation which has settled to about 2 to 3 inches thick. And last year when I purchased the home from my father, I tore all of the ductwork out of the home and reducted the whole house, took 3 months to do it. I then reinstalled the woodfurnace in series instead of paraelle, that alone made a world of difference. Today my wife loaded the woodfurnace with about 4 decent splits, probably 5 to 6 inches at 12:00 noon, when I got home at 5:00 pm the house was 78 and the woodfurnace had more than enough coals to keep the house warm, its been in the upper 30's today. I am the 3rd generation owner of the home, which I dreamed of owning when I was 5 and I now have it at 25. We put over 12,000 in it last year and we have much more to do, but it heats well and thats one thing I enjoy. Also we have 10 foot ceilings, ceiling fans are the key to some rooms. But basically every room is even heat. I have nothing bad to say about wood heat, love it! Our furnace hasn't ran once this year which is propane. The house is about 2400 square feet.