We just finished building a new house and I didn't insulate the garage but now, after some hindsight, I want to do. What's the best way to do it now that we can't insulate the walls? Is there something to do to the concrete floors or the garage doors?
We have the same problem in a new house in Arizona. On the doors, you can glue rigid foam on the inside, cut to fit and use a spray adhesive. There ia also a foil covered insulation that comes in rolls that would work but doesn't have the r value of the rigid. Attic, blow insulation but outer walls would be harder. Ours has only one outer wall to worry about and under the stucco there is 1 inch rigid foam insulation so that will help some.