Optimizing window configuration counterbalancing energy saving and indoor visual comfort for Sydney dwellings

Building penetrations are the most-potent elements providing daylight and moderating the lighting energy consumption and affecting indoor comfort and consequent energy usage. In a semi-tropical climate with a green environment such as Sydney, there is a radical demand to extend windows providing views. This research aims to optimize sunlight admission and maintain indoor comfort while minimizing energy consumption. The method for investigation is to simulate a multiobjective optimization using NSGA-II considering visual and thermal comfort along with energy usage and view of the outside. A combination of human and machine assessments responding to manual and microcontroller-operated indoor validating simulation improves the generalizability. The solutions were assessed for local codes compliance and double-checked against statistical sky conditions. Regarding north, a window-to-wall ratio of 10.7-20% delivers an optimum daylight metric, yielding a 12.16% decrease in energy use intensity. For an east-facing window, altering 26.4% of WWR decreases 2% in lighting energy and a provides a drastic change in visual comfort. Regarding west, changing WWR by about 51% brings about a 50% saving in lighting but no change in other energy loads. Regarding south, when window length is limited to 39% envelope width, it delivers the optimum energy consumption. This study covers visual and thermal comfort together with energy usage and view of the outside, which has not been investigated for southern hemisphere dwellings. A combined simulation and field measurement of human and machine assessment justifies the solutions.