Its your call. Its not enough ventilation where I live. Temps are in the 100's alot here & the predators are hungry. Here's one of my coops its positioned under a big tree so the birds don't cook. Three of the 4 sides have windows. My other two coops are three sided which is ideal for the long...
I would agree on adding some ventilation to the coop. You will eventually have to because old man winter will come & they will need to be inside. I'd add one more section of hardware cloth just to be safe. Guess I'm paranoid. I would hate to loose a bird because I was to lacy & cut corners but...