When to Move to Coop

[Rileigh]

Hello, all! My family and I are new to chickens, and we're trying to figure out when to move them to the coop. We have three chickens that we got through a farm store, so while we know roughly how old they are, we don't know for sure. One (a Delaware) is quite large (possibly too large for the brooder) and feathery. Another (an Easter Egger) is smaller and has tail and wing feathers, but not much more. The three can all fly and have been getting used to a roost. The Delaware and a Spotted Sussex are getting quite stir-crazy, and will try to jump out of the brooder. They are used to about 80-85°, as we approximate them to be 4 weeks old. Our idea was to place the brooder in the coop with the light and keep the door open, so if it gets too cold, they can go in. Where we are, it gets to about 70° daily, with a low of 50°-60°. However, we're not sure if they have the brainpower to do so. Any suggestions or advice?
Thank you!

 

[rosemarythyme]

Photos of the chickens can help us guess at their ages.

Assuming they're at least 4 weeks old they can definitely stand colder temps than what you're providing. It'd start turning off the heat lamp during the day to acclimate them to colder temps, then after a few days, assuming they're indoors(?) turn it off at night as well.

Any photos of the coop set up? I assume there's no other chickens in it? Honestly at this point, I'd probably give them a week or to get off heat and then move them outside and lock them in there a few days so they get used to it. No need to complicate it.