The only solution to this problem is new, denser housing. That way you can accommodate the people who've lived there for awhile plus all the new arrivals. But unfortunately it won't happen with rent control, strict zoning regulations, and restrictions on knocking down existing apartment buildings (to replace them with bigger ones). That's why SF has such a terrible housing crunch that is growing worse over time. I don't know why Berlin would want to go down that road too, but it seems to be their desire.
