Western WA pole building - Insulation

[diyengineer]

Wondering what i can do to bulk up the insulation. Last year it was anywhere from 20F-30F during our winter, and the heater "constantly running" (normal electric residential heater for a home ) could barely keep it at 50F inside (which wasn't cheap, or easy on the heater). I was amazed it could even hit 50. It did take 3+ hours to warm up. I'm considering an outside boiler furnace 250,000+ btu, instead of my lonely electric furnace mounted in the corner. It is sealed up pretty good, when i turn the lights out during the day, the only light i see is from around the large garage doors (they didnt install seals outside the doors, although they are tightly installed, not "light" tight enough).

For humidity control i use two portable dehumidifiers that i dump twice a day. They make a HUGE difference. Before, printer paper use to feel like a wet noodle because the humidity was 100%. Now it's under control.

65'x70' Single Concrete slab, metal siding, white (unknown R value insulation), 16 foot ceilings, 26' to the pinnacle of the roof. Has 3 garage doors, 16' tall x 12' wide, one man door, one 550 sq ft open loft.

Pictures of the pole building are attached.

 

[Cap-n-Cray]

If it is like my pole barn/shop the roof insulation is only about an inch thick under the plastic. It is mainly there to prevent condensation from dripping from the steel roof. If you don't put more insulation in, you will need more BTUs to heat the space. I have a insulated loft office with a pellet stove. The rest of the shop is slowly being insulated and has wood burners. I have one propane wall heater for the auto area and finish room.