I'm in the process of designing my next home and trying to figure out how to heat the garage in a manner that will not cause insurance companies to reject me. I understand that a woodstove in a garage is not kosher, although most rural people around here do just that without problems. There are no codes in this rural Montana county, the only objective is qualifying for insurance. I've read many threads here about heating garages and NFPA standards and narrowed things down to this: It seems that Outdoor wood boilers have a reputation of using MUCH more wood to heat a given area than indoor ones because heat is not radiated inside the structure to be heated. Not knowing much about boilers, it seems to me that if OWB's radiate that much heat, the issue is insulation. Would it be more efficient to build a super-insulated shack 2 feet from the garage to house an indoor boiler and a couple cords of wood?