I'm in the planning stages of building the dream coop. I've read about the concept of a structure that the south side is a greenhouse and the north side is coop. the ventilation between the 2 benefits both chickens and plants. the chickens breath out CO2 and the plants make fresh oxygen. They help keep each other warm as well, especially if I have a small composter going on the greenhouse side. It all sounds good in theory, but is this a permaculture sub-urban legend? Has anyone actual experience with this on a backyard scale?