Integrating daylighting and lighting in practice: Lessons learned from international case studies

This report presents lessons learned from twenty-five worldwide real-life case studies implementing the integration of daylighting and electric lighting. The case studies were monitored with respect to energy use for lighting, visual performance, non-visual performance, and users’ satisfaction. The monitoring is largely based on field measurements, but it is also complemented with simulations and calculations where needed. The report is divided in two parts. The first part provides an overview of the case studies and the overall lessons learned. The second part provides factsheets for each of the case studies; the factsheets include details on the monitoring, results, and specific lessons learned. Based on the lessons learned from the case studies, this report concludes that: • The energy demand for lighting is drastically reduced thanks to the combined effect of more efficient light sources, advances in controls, and raised awareness in the integration of daylighting and electric lighting. • Integrative lighting is currently driving the innovation in lighting technology and wider implementation is expected as knowledge in the field of non-visual requirements for lighting expands. • However, the current integration of the integrative lighting concept with daylighting in practice is limited, which may result in significant energy rebound (increases). • Daylighting integration is of utmost importance for achieving quality beyond energy savings. • Integrated daylighting and electric lighting design is facing new challenges: questions connected with comfort and health are yet to be answered.