We live in FL and were thinking of doing a similar design with wind/rain protection on three sides and a roof across 1/2 of the top portion and aviary netting on the other half.
problems with open design? - Page 2
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If your whole setup is going to be an open air type situation, without an actual coop, then netting is a bad idea. The reason most people choose to keep their birds in a coop at night is for predator protection. It's easier to build a simple structure with locks to shut them up in at night that is predator proof, than it is to do a whole run. You really have to make sure that it's as predator proof as possible. Consider, if you can get a couple fingers through a gap, a raccoon can get a whole arm in. Anything it can reach will get pulled to pieces. Snakes can get through small gaps as well.