The escalating global energy consumption of the building sector highlights the imperative for architects and designers to efficiently configure indoor spaces due to their profound role in energy utilization globally. However, in the prevailing reliance on mechanical air conditioning systems, the influence of passive architectural elements, specifically ceiling height, on energy consumption and indoor thermal comfort has been regrettably overlooked in recent years. This paper investigates the impact of ceiling height on the building energy performance in nine cities across Afghanistan characterized by a lack of standardized building regulations. Employing the BEopt™ software, comprehensive energy simulations were conducted, considering varying floor-to-ceiling heights ranging from 8 to 15 feet. The study reveals Precise effects, indicating that elevated ceilings have minimal impact on cooling loads but significantly increases heating energy demand. Therefore, lower ceilings are recommended in regions with predominant heating loads (e.g. Bamiyan, Chaghcharan, Ghazni, Kabul), while in cooling-dominated areas (e.g. Farah, Kandahar, Jalalabad), higher ceilings enhance energy efficiency. The findings indicate that a 1-foot increase in ceiling height corresponds to an energy demand increase ranging from 3.7% in warmer regions to 11.3% in colder areas. The findings provide insights into the relationship between ceiling height and energy efficiency, contributing to the development of standardized building regulations in Afghanistan.