What makes housing future-proof? If the inhabitants of a building run it for themselves, relatively autonomous, without much need for the interference of others - owners, property managers etc. They decide for themselves how to use the building, how to maintain it, how to connect it to its surroundings, how to develop it. To achieve this, several points are important: The building must be owned by its inhabitants, not individually but as a group. This group has to consist of people who know each other and are able to organize decisions among themselves efficiently and fair to all participants. And the group has to define (and, maybe, refine from time to time) a common target. While the materiality of many residential buildings might be fine for such a community, the immaterial, the organization of property and decision, seldom fits these criteria. Housing is usually developed by big companies, be it non-profit or for profit, which have different agendas than their tenants or buyers. That means future-proof housing is not mainly a problem of design of materiality, but of immateriality. Building cooperatives are one possible answer to this. In Vienna, building cooperatives have been a pilot model in the 1970s to 1990s but have completely come to a stop afterwards. For a few years now, new projects are being developed and the concept gains new importance and wins new supporters, but the conditions are still difficult. With my work I try to support the establishment of this model as a broadly used alternative. My work consists (in this case) of research, public information, education and lobbying, partly as member of the board of the non-profit association "Initiative fur gemeinschaftliches Bauen und Wohnen" (Initiative for community building and housing).