I’m in Florida. Walls are way too hot down here. No worry about snow load though
A fully enclosed would have been cheaper when I did the cover. But in TN I would have had then had to establish an effective ventilation system and that would have been significant even if it were just exhaust fans. I’ve ridden in some enclosed around here and they are not comfortable on hot days without some air movement!
Concur that “blow in” to be an issue. Actually, though, we don’t lose but a few days a year and then only an area on side or corner of the arena. The worst was when the remains if Hurricane Ivan thoroughly wetted the entire arena and it was too wet for several days.
On balance in our climate I remain convinced that a cover is the better idea.
G.
The fancy arenas around here have large windows you can slide open to basically make it a covered in good weather but you still get some protection for the footing from the kickboards.
Although, I’ll add that I prefer to ride in our indoor, which only gets ventilation from some large garage doors, in the summer here to get away from most of the bugs, pollen, and blazing sun. The roof is insulated, and it stays cooler. But I agree if you have a covered, birds are a major issue with insulation. We have enough of a problem with that and not that many birds get in.