In Saudi Arabia, residential buildings are one of the major contributors to total energy consumption. Even though there are abundant natural resources, it is somewhat difficult to apply them to building designs, as design variables, due to slow progress and private issues in Saudi Arabia. Thus, the present study demonstrated the development of sustainable residential building design by examining the daylighting and energy performance with design variables. Focusing on the daylighting system, the design variables were chosen, including window-to-wall ratios (WWR), external shading devices, and types of glazing. The illuminance level by these design variables in a building was evaluated by using daylight metrics, such as spatial daylight autonomy and annual sunlight exposure. Moreover, the building energy consumption with these design variables was analyzed by using energy simulation. As a result, the daylighting was improved with the increase in WWRs and the tinted double glazing, while these design options can cause overheating in a residential building. Among types of glazing, the double pane windows with a low-E coating showed better energy performance. Based on the results, it is necessary to find the proper design variables that can balance the daylighting and energy performance in residential buildings in hot climates.

Variable Transmission Glazing (VTG) windows are an energy efficiency measures that have relatively high first cost. This paper describes the in-situ performance of VTG installed in an atrium space at the University of Portland. An experiment was conducted using thermocouples and photosensors to examine temperature gradients and solar gains across electrochromic glazing windows to quantify the performance of the installed system in terms of energy and cost saving. The system performance was measured with an average efficiency of 98.73% when the VTG was operating. The annual savings of the glazing system installed was estimated to be $7,683.