I have a couple space heaters, but when I try to use them, the heat goes straight up and out of the garage, into the roof (no ceiling). I thought about adding one to enclose the space, but I store stuff on the rafters and hang things here and there, too. It's a single bay attached to the house (ranch style with a breezeway in between). I tell myself that my new shop will be heated/cooled. When I'll ever get it built, I don't know. Still hopeful, though.
Unless Mendon has specific codes against it, you can build a shed up to 200 sq ft w/o a permit. No frost protection foundation needed. That's 10x20, or 12x16, pretty good size for a bike shop. Insulated walls & ceiling and a small electric heater would warm it up nice. Just saying.

One of my bikes came with a K&N. I changed it back to OEM.