Agree with 3KillerBs that more vents (and more natural light) would be beneficial.Here's an inside/outside pic of the coop!
Here's an old post with examples of some different vent options, as well as how to protect them from the elements: https://www.backyardchickens.com/threads/sufficient-ventilation.1475311/page-2#post-24583587
Also not sure how big the roost is, but it looks a bit narrow and maybe close to the wall? It's probably ok for chicks but ideally you want a roost that's 2" or more in diameter/width, and 12"+ from the nearest wall.