Planning stages for 24x36 shop/garage. My goal is to keep the area above freezing when not in use and getting it warm enough for finishing in winter (say 50-60) here in southern New England. If I go with wood frame it would be 2x6 insulated walls and considering insulated steel structures. I am in the planning stages with nothing carved in stone besides size. Structure is detached from house.

No natural gas available.

Possible energy sources. Electric (last resort), wood, pellet, oil, propane or something I haven't considered yet.

I was thinking pellet with auto hopper feeder for lower attention during off hours and lower ash vs wood.

Like to hear your thoughts, pitfalls, options

Thanks in advance for your sage advice.