I'll be doing this shortly. The coops are not new, but have been changed in appearance, and DH is in the process of putting a fence around both of them. I have 'way too many roosters and once I can get rid of them, I plan to put all the hens (18 or so, I think) inside this fence and close the door for a week or so. I'm hoping this will work....the hens are grown, and very much used to going into a different coop, which I may take apart once I move them. Will it work? I have no clue. I'm just hoping. Each coop can have 10 chickens (coops are 5'X8'), and I'll have feed and water in both coops, so maybe they will just stay put. Or not! LOL
When we have hatched chickens here (many times) we would always put them in one of the coops after they were about 2 weeks old, and kept them confined in there until they were old enough to join the others. They would always go voluntarily back to the coop at night. But the older hens may not do that. And....they can fly out if they want to. There is no way to cover the area. I may end up being very disappointed. They free range during the day, so if I see that they have adapted to the new coops, I'll keep the gate open during the day so they can do their thing.