Love your run, an am glad that you have the roosts in it. When they are roosted up at night, measure how much space they are taking up, and add 3 feet to that. That would be a good measurement to know.
Keep that little coop - always handy to have an extra space once in a while. But if you can go with a shed, I would do so. Often times you can get a used one. Even if it looks rough, a lick of paint will help and chickens are not picky IF they have space. In Maine - I would expect snow, maybe heavy snow? You really need a building like a shed.
Another piece of advice for the run, IMO you need clutter in there. Right now, every chicken can see every other chicken 100% of time. There is no way to get out of sight. Pallets up on blocks, leaned against a wall, set up as a mini wall, can offer shade, a place to put a hidden feed bowl, and a way to get out of sight for a while. Good things to have in a run. A tote on the side or an open box can offer a place to get out of the wind. It really does not have to be the whole run.
The thing about 'free ranging' is that it is nice for chickens, I like to let my own out and about too. But it cannot make up for too small of a coop or run. They are not like dogs, where a little exercise, and they are content to nap. What one really needs is a space that will safely and happily keep chickens 24/7.
One needs adequate space for 3 reasons. The day length in the winters decreases dramatically, keeping your chickens roosted up for 15-16 hours a night. Ugly behaviors can start with overcrowding there. The weather - blizzard and they really won't spend much time outside. And predators - and once predators find you, they will be back and bring friends. When I get hit with a predator, I go into solid lockdown 24/7 for several weeks, so that the predator moves on.
I was afraid you had the pre-fab when you said they would not roost in it and your had 6 birds. Really - we as a community need to make them change that on all pre-fab coops.
Mrs K
