Comment by JanSt

German rents go up in most places. There was an influx of 1-2 million migrants and refugees, all of which need living space. Additionaly, it's very expensive to build living space because of very high special requirements for insulation and energy efficiency. It's not worth it / possible for investors to build profitable cheap living spaces, so mostly luxury apartments are build. There are also high ancillary cost (10-15% of price) - i.e. taxes, notary etc.