New technologies appearing in the market like semitransparent photovoltaics and motorized venetian blinds can make windows an active tool in controlling visual and thermal comfort, while allowing for energy generation. The goal of this study is to present a transmittance model for a triple glazed window with bi-facial silicon photovoltaic cells on the outer glazing and integrated venetian blinds, with the objective of integrating the model in a control strategy to optimize visual comfort and reduce energy consumption for heating by controlling passive solar gains. The model accounts for variations in the transmittance of the fenestration caused by changes in the incidence angles and in the blind tilt angle. A 9 surface radiosity analysis is then conducted to calculate the work plane illuminance obtained from the model. The results are validated using experimental data collected in a test room located in Montreal, Quebec. The RMSE between theoretical and experimental results has been reduced by an average of 46% for small blind tilt angles, and by 68% for large blind tilt angles compared to models in the literature.