I totally agree. The best money I spent on the shop was getting it fully insulated. Cold temps around here average in the low-to-mid 30's. With the insulation, I can fire up a 40K BTU propane heater and with two huge ceiling fans blowing the heat back down, a 15 minute warm-up period is all I need. Put on the mangy shop coat and it's time to turn wrenches in (relative) comfort.