With the overall goal to integrate and implement occupancy and occupant behaviour into the design process and building operation to improve both energy performance and occupant comfort, IEA-EBC Annex 79 will focus on: a) developing new scientific knowledge about adaptive occupant actions driven by multiple interdependent indoor environmental parameters, b) understanding interactions between occupants and building systems, c) deploying ‘big data’ for the building sector based on various sources of building and occupant data as well as sensing technologies, d) developing methods and guidelines and preparing standards for integrating occupant models in building design and operation, and e) performing focused case studies to test the new methods and models in different design and operation phases in order to obtain valuable feedback for the researchers and practitioners. The purpose of IEA-EBC Annex 79 is to provide new insight into comfort-related occupant behaviour in buildings and its impact on building energy performance. An open collaboration platform for data and software will support the use of data-mining methods and advanced occupant behaviour models. It will further promote the usage of this knowledge in building design and operation processes by giving policy support, preparing proposals for standards and providing guidelines for practitioners. Results of the Annex will be widely disseminated through conference and journal publications, journal special issues, panel discussions, presentations, books, technical reports, and guidelines.