How Can Reflected Light Modify Solar Gains in a Compact Urban District

Urban sprawl has become a major concern worldwide. The historical solution is the compact urban district, current in the old centers of many European cities. Their compactness presents many advantages that must be preserved for an efficient urban design. However, the compact urban district seems to be more challenging regarding daylight availability (Patriarche Mesure et modelisation de la lumiere naturelle dans les canyons urbains. PhD thesis, ENTPE, Vaulx-en-Velin (France), September 9, 2014) and solar gains (Beckers et al. Sustainable building for a cleaner environment. Springer, Cham, 2018). The study here presented has been realized in Rue des Tonneliers, a street of Old Bayonne, a heritage city in the southwest of France. Its compact morphology and high density have deserved an urban retrofitting project enhancing the livability of the district and its energy performance.