The document discusses research focusing on promoting energy efficiency in large buildings to achieve zero emission buildings (ZEBs). It presents initial case studies of large buildings in Norway, including a housing cooperative, health institution, university, and student housing organization. Preliminary findings suggest that energy efficiency management is currently characterized by local knowledge and initiatives rather than professional facility management. Greater involvement of "in-between actors" in building operation and an integrated approach combining design, technology, and user behavior are recommended to enhance energy efficiency.