My Brother built a 40 x 60 with 16ft sides. He built a 20x20 loft with stairs going up to it. Went up 8ft high off ground floor then put 4 ft solid railing around the upper level. Lots of extra storage. Still have bottom side for what ever. Plenty of room to walk around on upper level.
Get a...
Should be able to. I had a pole style building build back in 2009. Post were cemented into the ground. We just poured right up to the treated base boards. Still and looking good yet.
You could tear off the garage roof or only the width you need for a hoist and add your height there 12'.
Then you would have your height for the lift and the cost would be considerably less than a Pole building.
Just a thought!