My office is in the 12x24 section of my 36x24 shop. All 36x24 is
insulated - walls and ceilings. The office side has 2 man doors - one
to the outside and the other to the shop. The shop-side has a couple
of garage doors.

The 12x24 has a 220v electric heater.

I have plenty of hardwood on the property to heat - hedge, locust,
oak.

#1 priority is to heat the office, Mon - Friday 10 hours a day
#2 is to heat the shop as needed
#3 is to heat in the event we lose power to the house and need to live
in the office/shop for a few days.

Any thoughts on a low cost wood burning stove? Hedge burns hot --
I've heard stories of it turning stoves red.

I have a simple, low-slope, gabel roof, in case that influences the
chimney pipe.