Spend time in any historic European city and youll start to see a trend emerge: The same housing designs occur and again and again. Seen from the outside, buildings may vary greatly from street to street, but behind their facades, similarly configured units are reproduced much more uniformly than you might expect. But these iconic floor plans vary tremendously from city to city, and have played a key role in their host citys attitudes to housing. How did these housing standards come to be? And how did certain types of buildings shape citizens expectations about what is and isnt a real home?