Most existing daylight studies are focused on commercial buildings, with very few studies on residential. Due to flexible floor layouts of residential buildings and diverse interior activities, daylight analysis tools need to provide a flexible approach for designers to understand the horizontal illuminance distribution and light levels in multiple areas of the floor plan. When light levels are measured and averaged across the entire room, it is challenging to effectively distinguish the amount of light measured by each sensor point in different locations. This study introduces a novel computational workflow to customize illuminance ranges and select target areas to examine local light levels. The workflow allows users to further optimize the residential floor plan and fenestration design.