Jali screens are traditional window treatments in vernacular buildings throughout South Asia and the Middle East. Contemporary builders are starting to incorporate Jali screens as decorative façade elements; however, architects and scholars have largely ignored the impact of Jali screens on overall building energy and day-lighting performance. This research evaluates the effect of Jali screens, across a range of perforation ratios, on energy utilization and day-lighting quality in contemporary office buildings. The data collection and analysis is through fieldwork in Lahore, Pakistan, as well as through computational energy modeling. Results demonstrate that Jali screens have a promising positive impact on cooling loads and may improve visual comfort. The findings suggest a holistic perspective combining traditional architecture and performance enhancement by architects and designers.