we do have screens here, I have no clue if they are required lol but all the newish variety windows, doors with windows, and patio doors here have screens. so at my house the only windows that have screens are the windows we put in after we moved in, the rest of the windows are a really really old style that hardly lets anything in even when the windows are open lol they are just 3 golf ball sized holes covered with a board that you lift off and wala your window is "open"