Given the intensifying water scarcity crisis and the considerable share of the construction sector in water consumption, identifying and prioritizing the factors affecting water consumption reduction in construction projects has become a strategic necessity, particularly in megacities such as Tehran. The main objective of this study is to systematically identify and prioritize the key factors influencing water consumption reduction in residential construction projects in Tehran with an emphasis on sustainable construction principles. In this regard, a systematic review of the literature was first conducted and the extracted indicators were refined using expert opinions. As a result, three main criteria, technical, managerial, and design–planning factors and a total of 13 sub criteria were identified. The design–planning criterion was considered as a combined category because design decisions and construction planning processes are typically closely interconnected during the pre construction phase. The criteria and sub criteria were then weighted and prioritized independently using the Analytic Hierarchy Process (AHP). The reliability of the pairwise comparison questionnaire was confirmed using Cronbach’s alpha coefficient (0.87), indicating a high level of reliability. The overall inconsistency ratio of the model was calculated as 0.09, which falls within the acceptable range. The results show that the technical criterion, with a weight of 0.707, ranked first, followed by the managerial criterion (0.186) and the design–planning criterion (0.108). At the sub criteria level, the use of water saving technologies and equipment obtained the highest priority with a final weight of 0.3189. The findings indicate that focusing on technological solutions, alongside managerial support and appropriate decisions during the design and planning stage, can provide a practical framework for reducing water consumption in residential construction projects in Tehran.