The issue of “housing is too expensive” is primarily because of zoning. Most of Germany has zoning only in new, in-development districts. Major parts of most cities are not zoned at all.

This allows development of mixed use, middle-density (think: 3-8 floors) buildings, which provide a lot of housing at far lower cost compared to high rises.

These mixed, often mostly walkable, neighborhoods are what can help provide living space. Single-family housing is something that just gets cities into debt, increases traffic, yet does not improve the housing situation at all.