These structures can be customized to accommodate the wingspan of ultralites while still accounting for snow shedding and wind bracing. We have now shipped buildings for this application all over North America!
The challenge encountered when putting a shelter over an aircraft is that the wingspan is often greater then the overall length. Generally speaking, this would require a more expensive structure. When a building is wider, it would also be higher and catch more wind. For ultra lights and other such light aircraft, one alternative is to make a very low dolly which would allow you to move your craft into the structure sideways.
Since most available buildings are taller then they need to be, the profile can easily be modified to create a little more width. When increasing width you will decrease the snow shedding ability. This occasionally necessitates reduced hoop spacing.