Why houses have windows Windows are made out of glass and they are see through. sunlight comes through buildings.Windows have different frames like square, rectangular and more.if we did not have sunlight everywhere it will be so dark that we can not see. Sunlight makes us healthy. if we were in our houses we will have no fresh air but if you open the windows we will have fresh air in our rooms and everywhere else like cars and more thing that have windows.In your house if you don’t open your windows your house will smell