Our shop had heaters that would hang down in the path of tall overwidth loads, keep overhanging obstacles in mind while planning your building. Stuff will sneak into the way if you let it.
thanks for the numbers, I dont have the freedom to go wider than 11' on the doors so guess will stick with one 11' high for the engine and one at 14' for a rig (thought I might be able to do both at 11' high and save some lumber on the eave height of the building).