The living unit is currently undersized in Seattle multifamilyhousing. The design decisions for floor layout andunit configuration impact the interior daylight andoccupant visual comfort. This study uses the existingdaylight/glare metrics and investigates a simulationbasedworkflow. During schematic design, a series ofdesign alternatives will be compared regarding daylightperformance and glare perception. The decision-makingprocess is driven by the results of quantitative andqualitative simulation under the constraints of relateddesign codes. The final results will provide summarizeddesign guidelines that would be instructive for creatingwell-lit living spaces in Seattle.