One more questions! When framing out the smaller coops, are they 2x2 construction or 2x4 construction? It's hard to tell on some of the pictures. I know 2x4 might be more durable, but is it necessary, especially in a sheltered environment? I'd really like some input because as a woman leading her children to work on much of the project, I'd like to work with the smaller stuff. Any thought? Thanks Again!