well, the first one he built for me that my birds are in now, dh put windows in it and then added shutters. So if I shut the shutters it's airtight, but if I leave them cracked, it's ventilated. And the windows are at the very top of the house (it's barn-shaped, so high at the top) and wire mesh so the raccoons can't get in there. The new house is going to be double the size of the old one so hopefully, if the babies are girls and I keep them, I can integrate them all in the spring into one big house and just use the small one for storing feed and what not. Just because this is the first year we've had them, I'm worried about the cold. Yesterday while it was raining and they were free ranging in the yard, they all came up on the back porch to get out of the weather. DH isn't going along with my plan to convert the garage though, so have to tell him exactly what they need for him to build the new house.