The Noz Breizh Chair is a scientific consortium launched in 2022. This scientific chair aims to design transdisciplinary scientific programs and organize multi-partner scientific projects related to the night and nocturnal activities. There are three areas of research (social, technological, ecological) which, through an interdisciplinary approach, establish a dialogue and co-design theoretical and practical tools. Social : This area of research is dedicated to the analysis of the social practices of the city at night. It is based on scientific methods used in urban planning and sociology in order to understand and identify urban polarities related to nocturnal urban practices. Its aims are to conduct a detailed analysis that takes into account both people and activities of the night city, with the objective of improving the management of urban light policies (private and public). We work in partnership with sociologists and psychologists. Technological : This research area studies the role of public lighting of the “smart city” from a critical perspective, particularly with regard to the use of digital technologies in connection with the lighting network. We will explore the relationship between digital solutions and energy saving, as well as potential solutions to measure the impact of artificial light on biodiversity. We work in partnership with specialists in engineering and technology. Ecological : This third area of research identifies the nocturnal biodiversity of the defined study area beyond the most commonly studied species (e.g. chiropterans). The results can inform our hypotheses on the potential impact of decreased artificial light pollution on biodiversity. We work in partnership with researchers in ecology, biology and botany. We propose to present our first steps and protocols set up within the framework of the Noz Breizh Chair.