OK, you still need to open up top level venting because the windows on that are at roost level and don't provide airFLOW. Installing top-hinged windows as high up on the gable peak as you can manage -- remembering to think in square FEET not square inches. Here's a good example in an article about making a safe, adjustable prop:
https://www.backyardchickens.com/articles/window-support-for-top-hinged-windows.74810/
In addition to recommending that you don't keep any males this first season, I recommend that you don't push up to the limits of your space this first time and wait to get more until next spring. That way you'll know better what you're doing, what you like in a chicken, and what you want to avoid.
Some breeds do better in different areas and we don't always know what we like at first -- I never expected to love my Blue Australorps the way I do.