Dr. Jan Wienold is a leading expert in daylight research, visual comfort, and building performance simulation. His work focuses on understanding how daylight affects human perception and well-being, and on translating this knowledge into tools, metrics, and standards that shape climate-responsive and user-centered building design. He is internationally recognized for developing the Daylight Glare Probability (DGP) metric and for authoring evalglare, one of the most widely used tools for glare assessment in practice and research.

After completing his Diploma in Mechanical Engineering at the University of Stuttgart in 1993, Dr. Wienold began his career working on solar cooling and building simulations. He later joined the Fraunhofer-Institute for Solar Energy Systems ISE in Freiburg, where he spent nearly two decades as a senior scientist leading a research team on daylighting, building simulation, and zero-energy buildings. During this period, he completed his doctorate in architecture at the University of Karlsruhe (now KIT), conducting foundational daylight glare research in full-scale test rooms under real sky conditions. His PhD work resulted in the development of the DGP metric, which has since become the global reference for predicting daylight-induced glare and is now implemented in major European standards, including EN17037, EN12464, and EN14501. This early contribution earned several distinctions, including the Best PhD Award and the Best Paper of the Decade Award from Energy and Buildings.

In 2014, Dr. Wienold joined EPFL’s Laboratory for Integrated Performance in Design (LIPID) as Senior Scientist. He oversees the technical management of the lab, co-supervises PhD students, contributes to research strategy, and teaches the course Comfort and Architecture: Sustainable Strategies. At EPFL, his work continues to bridge scientific advances with practical applications to improve visual comfort, energy performance, and overall sustainability of buildings. His recent research includes projects funded by the Swiss National Science Foundation, the Swiss Federal Office of Energy, and European programs, addressing the dynamics of glare perception, interactions between color and discomfort glare, and the integration of high-dynamic-range imaging into standards for visual comfort assessment.

Throughout his career, Dr. Wienold has played an influential role in international standardization efforts. He was a key contributor to the development of the new European daylighting standard EN17037, which came into force in 2019 and marked a major step in bringing advanced daylighting research into building practice across Europe. He currently serves in multiple technical committees at CIE, CEN, ISO, and the Swiss SIA, where he works on daylight metrics, glare assessment, and harmonized daylight requirements. He chairs the CIE Technical Committee on glare measurements using imaging luminance devices and has initiated global efforts to develop a unified glare database.

Dr. Wienold’s research has been complemented by substantial contributions to building consultancy. He has applied state-of-the-art climate-based daylight and thermal simulations to high-profile architectural projects, including the double-skin façade of the Fraunhofer headquarters in Munich and the shading optimization for the ThyssenKrupp headquarters in Essen. These consultancy projects helped pioneer early examples of high-rise and office buildings that achieve exceptional thermal and visual comfort with minimal mechanical conditioning. His expertise has also been central to the design and evaluation of several zero-energy buildings, particularly in Korea, where he led the development of integrated daylighting, thermal, and ventilation concepts.