Here's a collection of images of rooftop living. Some are from a project I saw at the Berlin art school rundgang this year, in the architecture department (didn't see any names, but I think it was a collective student project). Some concern the use of rooftops in Japan, where I've seen temporary igloo-like structures erected on roofs to provide much-needed extra space, and where it's common for people to have parties or gatherings on rooftops in order to avoid disturbing neighbours.
The bottom row here is a "found street" on the roof of a semi-official squatted art building (a former factory) on Landsberger Allee here in Berlin. I often see structures like these on roofs and try to imagine them at street level. These ones, catching the late afternoon sun, looked like a "hidden" Japanese street up on the roof of a German building.
Someone left a comment after my Austerity after prosperity piece on Saturday asking about Kenji Kawai's beehive house, and adding: "I foggily remember a post some time ago about a commune in Germany with self-built shacks. This was you, right? Please provide a link if so."
The piece in question was Your inner hippy lives in Lohmuehle, a documentation of an alternative caravan community in the Treptower area of Berlin. Since photographing the outside of the wagon-like structures I've seen an exhibition (just next door to them) showing fisheye images of the interiors. They turn out to be surprisingly modern and luxurious inside (somehow you don't expect people to be using laptops inside alterna-caravans), and the wide-angle photography gives the impression, if not of vast space, at least of resourcefulness in giving that impression (the trompe l'oeuil forest murals, for instance). It's also interesting to see how many references there are, in these German caravans, to Japanese living.