It has been a tumultuous year for one prominent German property developer: his efforts to sell his penthouse atop a Nazi-era air raid shelter have stalled, and just weeks ago his firm filed for insolvency.

The one-two punch for the developer, Stefan Hoeglmaier, and his company, Euroboden, mirror the travails of the broader property sector across Europe¡¯s largest economy as it suffers its worst slump in decades.

For years, low interest rates fueled a global boom, igniting interest in German property, seen as safe and stable as the country.