Regarding 749.3041(2), can you clarify the difference between windows being used for ventilation and windows not used for ventilations?
If the foster family is opening the window to use fresh air from the outside to ventilate the room, then a screen is required. If they are keeping the windows closed and using air conditioning or fans to ventilate the room, then there is no need for a screen on the window. Generally, if they are going to open the window, we would expect a screen so that the house does not fill with insects.