My Cornish cross are 5weeks reds 4 weeks buff orpingtons not quite 4 weeks. They are almost feathered...just a few chick fuzz poking out yet lol they r cute the other 8 are supposedly almost 2 weeks. They r causing a ruckus in the house and no matter if I clean their pen twice a day they smell. This was the reason I kicked the others out...I figured the newest 8 will do fine with the light in one side of the coop so they can move if too hot etc. of course it will be a transition not just throwing them out....like I did with the others they have spent small amounts of time outside then after the fence is up and older ones r in new coop we can graduate to all day in the fenced run under coop. Then eventually outside (by this time they will be close to fully feathered like the last group lol. I am more worried with the older ones not having a light they haven’t had one last couple nights but it is ansmaller “house” the pics I am including are of the smaller house. I have the nesting boxes blocked off so currently the have just about half of that which helps them keep heat In im sure the other is our work in progress new coop for the older ones.How old are the older chickens? And how young are the others? I always kept the young ones in the house until they were fully feathered, then put them in the coop with no heat lamp.