It sounds like you need an arrangement like I had for my in-town birds (and hope to duplicate here with permanent, larger facilities). That is, a coop attatched to a predator-hardened run so that you can safely leave the door open 24/7.
All 1/2" hardware cloth firmly fastened to a secure, roofed structure (mine was half wire and half solid), with an anti-dig apron. Electric in addition if you've got a high predator load.
All 1/2" hardware cloth firmly fastened to a secure, roofed structure (mine was half wire and half solid), with an anti-dig apron. Electric in addition if you've got a high predator load.