One of the best things I’ve become aware of for shops here in the sunny south is radiant barrier material in the ceiling or underside of the roof. It’s cheap & only about a 1/4” thick but does a great job of reflecting the sun’s heat. I first put it in the ceiling of the 18x 30 garage at my house. I was amazed at how it lowered temps inside the building. Since then I had it installed in the 40 x 60 building we built in 2021. Since then we added a 100 sq ft restroom to that building & used the radiant barrier there too. Stuff does an amazing job at keeping heat out of a building.

1966 C-10 Short Stepside
HiPo
Step-by-step ~ and on-going resto build
in the Project Journals