1 big coop or several smaller.

[lazy gardener]

I would go with big coop which can be divided as needed. Less work to feed and water flock if they are all in the same building. Not to mention, not as many integration issues.

 

[aart]

By heat the air I meat the chickens body heat heating the air, or more so escaping into the air. I find big coops and not enough chickens make cold birds.

Most of a chickens body heat is trapped by their feathers.
A coop will only 'hold heat' (no matter the source) if there is a lack of ventilation.

 

[aart]

This comes to mind....

https://www.marthastewart.com/914692/chickens-and-their-coop

Gary

 

[oldhenlikesdogs]

This comes to mind....

https://www.marthastewart.com/914692/chickens-and-their-coop

Gary

I love Martha Stewart, and love her coop. She counts her eggs when she collects them just like I do.