I built a Cleary hangar about 12 or so years ago. It is pole barn style on a slab. It is 60x50 with a 13 ft door height below the bi-fold door. The materials supplied by Cleary were top notch. The erection team was a Cleary group that did a very respectable job on the erection/construction. There were three of us on site building very similar hangars from Cleary relatively simultaneously. The others were a little ahead of mine, and when I saw the metal roofs were being put on without a vapor barrier, I immediately told them I had to have a vapor barrier. They said it was a change order, so it would be $500 processing fee on top the cost of the changes. I couldn't understand how it was reasonable to even consider building a structure in the northern climes without a vapor barrier. (Without, if conditions are just wrong, moisture can condense on the under side of the roof and it will rain inside-when it is not raining outside!) it was an item I was dumb enough not to think to discuss and include in the contract. I tried to get them to waive what I saw as a $500 penalty for a change order. No deal. I paid to get it done right, and the local kid that was the area salesman and "manager" really stuck it to me for materials and labor, too.
Oh, don't let them bring the bi-fold (metal skeleton) door cross country in winter. All that de-icer on the highways of the Midwest will coat the door skeleton on the flatbed and, voila, rust!
Overall I am happy with it. Make sure the contract spells out everything exactly as you want it to be, lock, stock, and barrel.
lc
An aside- that was 12 or more years ago. Things can change at all levels in most any company in that length of time....
Humor may not make the world go around, but it certainly cheers up the process...

With clothing, the opposite of NOMEX is polypro (polypropylene cloth and fleece).
Success has many fathers...... Failure is an orphan.