Here in Denmark most people have forgotten the "rule" about not hanging washing out on a Sunday or other religious holiday, but washing is hung in the back garden if you live in a house. Housing associations and blocks of flats do have rules about where and when you may do your washing or hang it out. Usually, if you share accommodation /live in flats you can't use a washing machine or dryer between the hours of 9 p.m. and 7 or 8 a.m. Some places allow you to dry washing in a backyard, in others you may hang washing anywhere, but most commonly washing hung on your own balcony has to be hung below the level of the balustrade, so it is not visible to others.
Someone once told me, but I don't know if it is true, that in Switzerland you hang your washing in the front garden so everyone can see how nice and clean it is!