Still thinking on it, I have 4"-6" of gravel in a foam board insulated floor for solar absorbtion during the day and I plan on adding some black water tanks to that as well. Right now I'm leaning toward a rocket mass heater with some water heating addition, so I can capture the heat and it can be released later on at night in one methoed or the other. I'm also looking at designs that will allow me to use an auto feeder to feed wood pellets when I'm not around to feed it myself or on cold nights. I probably will need a backup also like a small propane or kerosene heater just in case. And I'm open to suggestions if anybody has any additional info to add. I guess I really should start another topic for this.