Detroit is an urban hell. But even in this city of the dying auto industry, there is reason to hope, if they manage to combine the creative forces of designers and other intellectual "suppliers" in other ways.

The Germans are often too bureaucratic, too fixated on rules and not risk-oriented enough. And some of their officials have the feeling that they need to make everything in the cityscape look nice and pretty as quickly as possible. That was particularly apparent in the former East Germany after reunification. Then cities sometimes get a bit too neat and tidy.

Hamburg is getting a new symbol with its new Elbe Philharmonic concert hall. Such an architecturally impressive building is built somewhere in the world maybe once every five years, if you're lucky.

All cities have one key resource: the special abilities of the people who live in them. You just have to find out what they are. In the Australian city of Adelaide, for example, which is overshadowed by Sydney and Melbourne, I discovered a number of experts in the penal system. I advised them to work with these special skills.

In a city like London, the fact that cultures live together and cross-fertilize is a beautiful and natural thing. The many cultures in Amsterdam contribute to the city's high level of craziness - something which every interesting city should offer. But sometimes immigrants can live in parallel worlds which can exclude others and not be very attractive.

City needs creativity to retain the high performers who have lived there for years as well as to attract new, interesting residents.

Another thing I like about German cities - and it's an advantage which they haven't sufficiently exploited yet - is that they are pioneers when it comes to environmental technologies. And green solutions are becoming more and more important.