Most hangars that use a bifold door need to be taller to accomodate the door. My 48x48 has a bifold door that opens 14' and even with a low pitch roof that translates into a 21' peak height. And you would be surprised how tall tri gear airplanes are and you also have to allow for the tail to bounce up and down as the nose gear springs over the edge of the floor coming in and out. Do not buy a door that opens too little.

Building codes and requirements vary from town to town and state to state. My hangar is on property that is zoned residential and is an accessory use building, i.e. a barn. As a result, I was able to be the general contractor and do all of the excavation, wiring, and interior work myself with periodic inspections by the town building inspector. If I had put up the same hangar at the municipal airport it would have been zoned commercial and I would have to had more involvement by licensed trades-people. I will note that the residential building code does not have rules for airplane hangars, so I built a barn, which is covered. A hangar is really just a machinery storage building with a large door. No more no less. So check with the building department in your locale as to whether your location is commercial or falls under a different category.

Construction is a whole 'nother knowlege area that has its own set of standard practices and rules. All of those are intended to have you put up a building that will not fall down, blow down, or burn down, so it is worth understanding the whys and wherefores. As the east coast storms of the last few years have shown us, you do not want to arrive at the airport and find that the hangar has crushed your pride and joy flying machine.

Best of luck,

Wes
N78PS