I am building a coop/run for my daughter. We live in NorCal SF East Bay where temperatures hit 32F and 100F only a few days a year. I am building a shed type coop with a slanted roof, 6 at the front and 5 at the back. Do ventilation holes at the top of the front and back walls need to be adjustable or are screened holes that are open all the time acceptable? I will be installing windows that may be opened.