i would brood inside until the weather's good enough to turn out (or if you have a smallish house you can put heat in for them) and keep them separated from your older birds, but close enough they can get to know each other thru wire...Let me just ask the Dorking pro's :
should I brood the Chick's in the hen house or in with us in say the bathroom where they are safe and can be watched closely until they get bigger..or (!) Make this choice if we still have freezing cold weather?
well, not having extra pens, i brood inside, then move outside and free range as soon as they've been outside a few weeks... htat gives the older birds time to get to know them, so they don't get chased or pecked. unfortunately, between the weather and predators (and 1 being stepped on by a horse...), my 20 mille fleur cochins are down to 6... but hopefully by the time i have another large group of chicks, i'll have my breeding pens done, and 1 will be dedicated to babies only.