To block noise, without blocking light. See for example [0] (in Budapest, Hungary), where the house would not get much light during the day with a solid barrier

To block noise, without blocking light. See for example [0] (in Budapest, Hungary), where the house would not get much light during the day with a solid barrier and it's also kinda depressing to stare at a wall immediately in front of your window (even a busy road is a better view). (Note also the bird stickers.) [0] http://iho.hu/img/kozut/111004_kaotikuskoki/zajfal.jpg http://iho.hu/img/kozut/111004_kaotikuskoki/zajfal.jpg