Phil,
Just a friendly word of caution . . . . about predators.
Raccoons and other critters will eventually find your flock and kill birds.
During the day [if the birds free range] you will eventually loose birds to hawks.
The windows I installed did come with screens - which I left installed...
Phil,
You're right chickens can take cold better than heat.
You need to add windows to your shed.
I installed these windows in my shed . . . without cutting any 2x4 studs.
14" x 27"
Safety Glass
White or Brown
Flush Mount or J-channel Mount
$33.00 ea
Lot of 4 $129.95
Here is a...