I love the rocket mass heater but the home we are getting ready to move into to house 20+ (unwed mothers and our family) is a massive 6100 square feet. It has three large living areas and bedrooms that are larger than most peoples living rooms. No- most of you wouldn't want to live in this and believe me we have never lived in such a beast!! I am hoping to heat it with rocket mass heaters

)) Not just because they would save on our utility bill but they are wise for the environment. How many will I need to heat such a space? I have no idea how to calculate. I can imagine getting carried away and turning it into an oven. We will be grinding our own grains and making our own bread but let's not go overboard! I also need the best, detailed instructions on building them so as to keep all of us safe!