Stiftung trias is a non-profit foundation based in Hattingen, Germany, established in 2002 by a group of professionals and organizations active in co-housing and alternative land use. The foundation emerged in response to the observed challenges within the co-housing sector, such as scarce funding, limited access to land, and fragmented knowledge. Unlike traditional foundations, Stiftung trias does not have a single major donor, but rather was funded by over 200 contributors from civil society, functioning as a Bürgerstiftung—a citizen-run foundation with specialized expertise.
The foundation’s core mission is to remove land from speculative markets and ensure its long-term use for social and ecological purposes. It achieves this by acquiring properties and granting long-term heritable building rights (Erbbaurecht) to project groups. The groups pay a lease fee, which is pooled to enable further property acquisitions and support new initiatives. As of 2022, over 50 projects in Germany have become part of the “trias family,” spanning residential, work, and cultural spaces. The foundation had grown its initial capital reserve from €70,000 in 2002 to around €10 million, supported by more than 90 donors.
A notable example includes the collaboration with the Edith Maryon Foundation to acquire and repurpose the former Rotaprint factory in Berlin, now leased to social and cultural projects, artists, and local businesses. Another current project is the site in Schöneberger Linse, Berlin, developed with a focus on inclusion, ecological design, and community management. Stiftung trias is regarded for maintaining strict separation of land and building ownership, prohibiting resale for profit, and ensuring properties are self-managed and dedicated to collective, sustainable goals.