Luminous condition of urban canyons; an evolutionary computing-based approach to simultaneously improve outdoor illuminance and indoor visual comfort

Abstract Due to the rapid population growth, urban densification is inevitable. As cities become denser, the environmental quality of urban canyons reduces, and thus the associated energy use of buildings increases. Currently, cities are responsible for 70% of the world’s energy consumption. One of the efficient solutions to address this issue is allowing more solar access into interiors and thus making the most of daylight and solar heat gain. Accordingly, this study aims to develop general daylighting guidelines by optimizing urban and building design factors. This ultimately allows more daylight penetration into urban canyons (vertical daylight illuminance (VDI)) and, subsequently, improves indoor visual comfort (useful horizontal illuminance level (HIL)). This can also reduce the associated lighting and heating (during winter) energy use of buildings. Moreover, the correlation between indoor and outdoor illuminance levels is investigated to bridge the gap between daylight requirements in urban planning and building scale design. In this regard, a multi-objective evolutionary algorithm-based assessment of design variables is conducted employing computational simulation. This determines the extent to which each urban morphology can affect daylight access in both indoor and outdoor environments. Accordingly, the optimal range for different design factors is suggested.