Yesterday DBF bought a lovely playhouse for me to convert into a coop. The biggest issue I have is should I insulate it? There are three large windows on 3 walls. One is going to have nesting boxes installed and the other two will be made into working windows. The 4th wall is obviously the door. We're right between zone 6a and 5b (coldest temps between -5F and -15F) and I'm wondering if it is worth insulating the whole coop or should I just do the roof? because of the large windows on the walls, not to mention the openings I'll add for ventilation, I'm afraid that attempting to insulate the ENTIRE coop will be a piecemeal job and a waste of money. I don't want to spend $50 and only use $5 worth of materials. We have 20 chickens, so they should be able to keep each other plenty warm, right? All opinions welcomed! Thanks for your help!