by the 1960s and 1970s, a few new apartment blocks had been built here and there. in the wake of the agglomeration of zürich, weiach became subsumed by the city in the mid 1980s. new residential areas were designated according to the "quartierpläne". this triggered a construction boom, beginning on the edge of sanzenberg. 30 per cent of the apartments which existed in 2000 had been built in the previous ten years. the population grew by over 35 per cent thanks to the building of 80 new apartment blocks between 1991 and 2000. never before had so many people lived simultaneously in the parish of weiach. the start of urbanisation can be seen from the explosion in the number of single person households from 1990 (an increase of 132 per cent).