My garages have been 24x28, 24x36, 18x24, 18x40, 30x40, and 12x24.
It's nice when the size can be heated and cooled 24/7.
Collecting excess stuff wasn't a problem with the 30x40. Climate control was expensive. I myself would not do another 30x40x14.
The finished 18x40x10 was a good size. I got a...