I don't know your Breed - and I think body pics will be needed - as hackle, tail and saddle feathers grow. On the move to outside, I began by pulling the brooder box to a sunny porch, at 3 weeks old, monitoring temperatures often to be sure they'd be comfortable. Then at 4 weeks, I carried each of mine out to a Chick Tractor most afternoons and warm mornings from 4 weeks on, with 1 night outside on a warm evening. Inside on rainy/windy days/nights til 6 weeks, with a couple nights under light, covered out on the porch. Now they are mostly outside, but need cozy roosts, wind, rain and predator protection - and light turned on before dark. or someone chirps loudly.
I assume you are reducing temps by 5 degrees each week? If outside temps are comfortable, and they can get adequate shade and wind protection, why not start transitioning them to a larger outdoor space so they can run around, sunbathe, dustbathe and learn to fly-hop to higher roosts? It allows you a chance to clean the Brooder, and they get used to moving when it is time to roost. Our neighbors love to stop and see the Chicks while they are out walking or biking with their dogs and kids. Our Chick tractor is 4x8, and their night space is usually separate, and almost completely covered. Our CHicks are now approaching 7 weeks old and doing great outdoors, as night temps are in the high 50's. They move to fresh grass for play daily. I've begun teaching them to transition to-from the Chick Tractor to their night shelter by a tunnel system. It's fun to watch them explore to figure it out. I set food or tap where I want their attention to be, and a leader always emerges and takes a victory flight to celebrate being first to occupy their familiar day roost without being picked up and carried. Take time with it, check them often, and have fun watching them explore!
