Analyzing the impact of structural system modifications from steel to cast-in-situ concrete on project cost and timeline: a case study of the main load dispatch centre expansion project in Lugogo

Abstract

This study investigates the cost and timeline implications of modifying the structural system from structural steel to cast-in-situ concrete during the refurbishment of the Load Dispatch Centre at Uganda Electricity Transmission Company Limited (UETCL) Control Center in Lugogo. The original design proposed a steel frame to support an additional level on an existing structure without impacting any load on it; however, this was revised to a cast-in-situ concrete frame due to unavailability of the specified steel sections on the local market. The research employed a case study methodology, using project records, design documents, construction logs, and site observations. The analysis focused on timeline deviations, cost implications, workmanship quality, design integrity, and coordination challenges. Findings reveal that the structural system change had cascading effects—most significantly a threefold increase in the project duration, from six months to twenty. Delays were to foundation redesign, procurement constraints, and local labor capacity issues in implementing specialised components such as the suspended floor system. Despite these setbacks, the project highlighted the importance of flexible architectural design, coordination under pressure, and adaptive project management strategies. The study concludes by recommending proactive supplier engagement, context-specific structural decisions, and a more integrated design-and-build approach. These lessons contribute valuable insights to construction management practice in refurbishment scenarios.