Oh, and while you might like the noise, I think the bunnies will prefer being noise free. I can listen to the noise inside all I want. But sitting in what is basically an echo chamber with a tin roof on top without anything in between doesn't sound like fun to me. I'm not going to bother building an inner roof for the bunnies, just a framework to support the roof. And the walls will be a single layer of TnG without any insulation or similar constructions.