German house prices are up only 8% (cumulative) since 1970
Germany's mortgage market was equivalent to 40.5% of GDP in 2017. This is not surprising as Germany has one of the lowest home ownership rates in Western Europe at 51.9%.
Looking at the Canadian mortgage market we see a different story. The Canadian mortgage market expanded from 39% of GDP in 2000 to over 68% of GDP in 2017.