[danohu]

Berlin is pretty dense, even without skyscrapers. Tightly-packed six-storey buildings can get you very high density (look at Paris for a more extreme demonstration). The area of Kreuzberg I'm in now has the same population density as Manhattan (28,000 people per square kilometre), despite not having anything more than 7 storeys high.

Housing everywhere in Berlin -- especially new-build -- is very dense. Importantly that's true throughout the city, not just in the centre.

Keeping Berlin so dense is an impressive achievement, given that it's surrounded by flat, empty countryside. Partly it's because of the cold war division of the city. But mainly it's cultural -- most Berliners are happy with apartments rather than individual houses.

Politicians religiously promise to maintain the 'berliner mix', where zoning encourages housing and commercial use in the same area, and keeping a social mix by having affordable housing everywhere. A new higher-density mixed-use zone category ('urban area') has just been introduced nationally, largely at Berlin's request.