I just built a detached 30 x 40 garage, exterior is complete the interior is not. I'am thinking of possibly installing a wood boiler either in the garage or in the basement. A lot of thought went into the garage to build it to fit my needs, so far I'am very happy with it. When the trench was open for the utilities 48" deep, I purchased some 4" pipe with two 1" pex lines wrapped in bubble/foil, non oxygen barrier !! type and layed it down 70' total. Yes !!, I did not do my home work, I messed up. This pipe was suggested by a friend who has a OWB. If I installed the boiler in the garage I would like the storage to be in the basement of the house to save on floor space. The house is 2400 sqft, with some under floor radiant, and radiant baseboard, the garage floor has 1200' 1/2" oxygen barrier pex. From info I have gatherd it will cost me around 1000$ to heat the garage to about 55 degrees if I go the propane route, and the house is using 800-850 gallons of oil a year. And I do have basement access. Interested in peoples thoughts on this. Thanks