Well, I have 5 hens currently, but I also have a second , smaller coop for them inside their fenced run, which is pretty big. Also, they're only indoors when they want to be (to nest/lay eggs, and overnight when they're locked up. )The rest of the time they're free either in the run or in our backyard where the run and coop are located. And ventilation: I've drilled 2 inch holes all the way around the top of the shed, right below the roofline, and sometime in the next week my husband will be using a jigsaw to cut out and then put in a 2x2 window on one side, about 4 feet up, which will be covered in hardware cloth. I am not sure yet what kind of ventilated winter cover I'll create/build to put over the window next winter when it gets really cold again (we're definitely starting to see early spring here in Tennessee at this point, so the weather is getting warmer quickly)