Buildings account for over one-third of global energy consumption and energy-related carbon emissions, making the optimisation of renewable energy utilisation a central objective in low-carbon building design. Although photovoltaic (PV) systems are increasingly deployed in institutional buildings, renewable performance depends not only on installed generation capacity but also on the temporal alignment between electricity demand and solar generation. Daylight availability offers an opportunity to influence this demand–generation relationship, particularly in tropical academic buildings where peak solar irradiance coincides with daytime occupancy; however, daylight performance and photovoltaic utilisation are typically analysed independently. This study evaluates how daylight-responsive façade strategies influence renewable energy utilisation in a multi-storey courtyard institutional building in Lagos, Nigeria. An integrated simulation framework combining Radiance climate-based daylight modelling and EnergyPlus energy simulation was applied to five façade-control scenarios. Daylight performance was analysed across horizontal depth zones and vertical floor levels, while renewable utilisation was assessed using Renewable Energy Fraction (REF) and PV Self-Consumption Ratio (SCR). Integrated façade control increases daylight penetration and reduces annual lighting electricity consumption by 33.5%, lowering daytime electricity demand during peak solar periods. Consequently, REF increases from 19.5% to 20.5%, while grid electricity imports decline by approximately 35,100 kWh annually. These results demonstrate that daylight-responsive façade design can function as a demand-side renewable optimisation mechanism, improving photovoltaic utilisation by reshaping daytime electricity demand in institutional buildings.