This study investigates the major constraints affecting school building construction projects in Dhangadhi Sub-Metropolitan City, Nepal, with a focus on identifying and analyzing these limitations to propose effective remedial measures. Drawing from the Theory of Constraints (TOC), the research examines various factors such as financial, administrative, resource, technical, environmental, legal, and social constraints prevalent in the construction sector, particularly in developing countries like Nepal. Using a mixed-methods approach, data were collected through questionnaires and interviews from 34 technical personnel involved in 24 selected school building projects (20 completed and 4 ongoing), each with a contract value exceeding NPR 20 lakh. Principal Component Analysis (PCA) via IBM SPSS was employed to reduce 28 identified constraints into seven key components: Financial and administrative challenges, Resource management and coordination, Strategic management of on-site challenges, Project planning, labor issues, and cost estimation, Project scheduling and financial forecasting, Stakeholder engagement, and Budgeting and decision-making issues. These components account for 79.338% of the total variance, highlighting critical areas like delayed payments, coordination issues, and inadequate planning. Similar PCA-based categorization of construction delays has been successfully applied in Nepalese municipal projects (Nepal et al., 2024). The findings underscore the need for improved policy frameworks, better resource allocation, and enhanced stakeholder involvement to mitigate constraints and ensure timely, cost-effective project completion. This research provides valuable insights for project managers, contractors, and policymakers in Nepal's construction industry.