The foundation stone was laid for the openOffice hybrid house in the grounds of the UNESCO World Heritage Site, the Zeche Zollverein colliery and industrial complex in Essen, on September 11, 2009. The openOffice hybrid house is one of five winning designs selected through the architectural competition, Mobile Working Spaces. It will be exhibited, for at least two years, as a temporary office building within the "designstadt" in Essen. The original aim of the competition was to develop experimental, temporary offices and studios for creative entrepreneurs. However, since then the range of intended purposes has been extended to create temporary space for public institutions such as nurseries and schools, a refectory, a library, etc., all incorporating energy-self-sufficient building technologies. In their search for a truly alternative and self-sufficient heating method, Dipl.-Ing. Rüdiger Karzel, architect at bk2a architecture in Cologne and lecturer at TU Darmstadt, specializing in “design and industrial methods of building construction", with his team and students finally decided in favor of SOLAR-RIPP ® solar heating. The heating elements are going to be designed for, and installed at the gable ends of openOffice, partly as semi-transparent canopies, and will be integrated in the service water heating system. The room installation can be viewed for the entire duration of Essens Kreative Klasse 2009. It is part of the exhibition portfolio of RUHR.2010, the European Capital of Culture 2010.