Insulation of the shop is going to be very important, because we get huge temperature swings through the year, with a high of 114F and low of 19F in the last 12 months.  Money I spend on insulation now will pay itself back dozens of times, even with me using my own solar generated electricity.

I prepped the attic by cutting into the soffet and installing soffet vents at three points along each long wall of the building. This gives the opportunity for air to enter the vent, heat up, travel up the underside of the roof, then out the spinner vents on the top of the roof.  Without the soffet vents, there would be no air source to set up the good flow.  I caulked up the gaps and painted to match the original color.

The installers used Cocoon 2 cellulose, an environmentally friendly insulation, blowing in R-30 in the ceiling and R-13 in the wall stud bays.  They cut a 2.5" hole near the top of each stud bay, fill up the bay with cellulose, then plug it with a 2.5" styrofoam plug.  I taped and mudded the plugs over during my drywall touch-up.