Hello again, sorry I didn't get back to you til now...busy time!On the narrow side, there is a door within a door, for the chickens to leave and enter.We are going to lean a 2*4 that has been scored similar to the "ladder" inside, so the chickens can get in and out. It will be taken down after they have bedded down at night, and they will be sealed inside. I think what you saw was the ladder for the chicks to be able to get from the floor to the roosts if they want to... I know that soon they won't need the ladder, but it's good for them now, and won't hurt anything later.
I would love your opinion on the ventilation. There is ventilation from 3 sources: the floor opening, the saw spacings around the front and back doors, and on the tall side, there is a gap along the top, between the wall and the roof, made by the narrow side of the 2*4s that support the roof. On the short side, the wall was notched to fill the gap. The egg boxes, food and water are all going to be on the narrow end, hopefully away from any direct wind, and there will be some space not in the egg boxes for chickens wanting out of any breeze. the floor opening is protected from critters by both the catch pans and the hardware cloth. Anything the saw spacing or hardware cloth lets in will probably become chicken food, and the space along the top is small enough to stop anything other than snakes or rats, which would have difficulty getting up that high. Thinking about it now, I might add a strip of hardware cloth up there, just to make sure.
This is the first time I have done more than just repair a coop, so I am quite happy to get input.
1)
Quote: Did you mean to say a 2" x 4" board? As your girls get mature there's no way that will be sufficient. And you really don't have to be able to take it down at night to 'seal' them in. Believe me, that will get real old real fast....put it up, take it down, put it up, take it down....

2) Ventilation...
Quote: The first thing you said that has me concerned is the "floor opening". You never ever want drafts coming up from the bottom of your coop into it. Why? We live in Oregon! And you know our winters can get really cold. I would suggest you re-think having wire for your flooring of the coop...besides, that will be hard on their feet over a period of time. I would put a small ventilation opening on both ends of your narrow walls up high to let hot air/humidity escape (yes, escape). Since you are limited on areas you can actually put in a window opening I'd suggest putting 1 window on one end only.
Glad you re-thought about putting hardware cloth over those openings. You will not believe how little a 'space' predators can get away with in getting in to your coop.
So there you have it. Now my next question....do you plan on putting up a run?